Rhoton Yoshioka Atlas of the Facial Nerve

Unique Atlas Opens Window and Related Structures Into Facial Nerve Anatomy… Atlas of the Facial Nerve and Related Structures “His meticulous methods of anatomical dissection and microsurgical techniques helped transform the primitive specialty of neurosurgery into the magnificent surgical discipline that it is today.”— Nobutaka Yoshioka American Association of Neurological Surgeons. Albert L. Rhoton, Jr. Nobutaka Yoshioka, MD, PhD and Albert L. Rhoton, Jr., MD have created an anatomical atlas of astounding precision. An unparalleled teaching tool, this atlas opens a unique window into the anatomical intricacies of complex facial nerves and related structures.

An internationally renowned author, educator, brain anatomist, and neurosurgeon, Dr. Rhoton is regarded by colleagues as one of the fathers of modern microscopic neurosurgery. Dr. Yoshioka, an esteemed craniofacial reconstructive surgeon in Japan, mastered this precise dissection technique while undertaking a fellowship at Dr. Rhoton’s microanatomy lab, writing in the preface that within such precision images lies potential for surgical innovation.

Special Features • Exquisite color photographs, prepared from carefully dissected latex injected cadavers, reveal anatomy layer by layer with remarkable detail and clarity • An added highlight, 3-D versions of these extraordinary images, are available online in the Thieme MediaCenter • Major sections include intracranial region and skull, upper facial and midfacial region, and lower facial and posterolateral neck region

Organized by region, each layered dissection elucidates specific nerves and structures with pinpoint accuracy, providing the clinician with in-depth anatomical insights. Precise clinical explanations accompany each photograph. In tandem, the images and text provide an excellent foundation for understanding the nerves and structures impacted by neurosurgical-related pathologies as well as other conditions and injuries.

An exceptionally stunning anatomical reference, this book is a must-have reference for residents and advanced clinicians specializing in neurosurgery, facial plastic surgery, oto- laryngology, maxillofacial surgery, and craniofacial surgery.

Nobutaka Yoshioka, MD, PhD, is Director, Department of Craniofacial Surgery and Plastic Surgery, Tominaga Hospital, Osaka, Japan. Albert L. Rhoton, Jr., MD, is R.D. Keene Family Professor and Chairman Emeritus, Department of Neurosurgery, University of Florida College of Medicine, Gainesville, Florida, USA.

An award-winning international medical and scientific publisher, Thieme has demonstrated its commitment to the highest standard of quality in the state-of-the-art content and presentation of all of its products. Thieme’s trademark blue and silver covers have become synonymous with excellence in publishing.

ISBN 978-1-62623-171-9

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ffirs01.indd i 2/10/2015 1:41:03 PM ffirs01.indd ii 2/10/2015 1:41:03 PM Atlas of the Facial Nerve and Related Structures

Nobutaka Yoshioka , MD, PhD Director Department of Craniofacial Surgery and Plastic Surgery Tominaga Hospital Osaka, Japan

Albert L. Rhoton , Jr., MD R.D. Keene Family Professor and Chairman Emeritus Department of Neurosurgery College of Medicine University of Florida Gainesville, Florida

With 97 Illustrations

Thieme New York • Stuttgart • Delhi • Rio de Janeiro

ffirs02.indd iii 2/10/2015 2:07:52 PM Thieme Medical Publishers, Inc. Important note: Medicine is an ever-changing science undergoing 333 Seventh Ave. continual development. Research and clinical experience are continu- New York, NY 10001 ally expanding our knowledge, in particular our knowledge of proper treatment and drug therapy. Insofar as this book mentions any dosage Executive Editor: Timothy Hiscock or application, readers may rest assured that the authors, editors, and Managing Editor: Sarah Landis publishers have made every eff ort to ensure that such references are Editorial Assistant: Nikole Connors in accordance with the state of knowledge at the time of production Senior Vice President, Editorial and Electronic Product of the book. Development: Cornelia Schulze Nevertheless, this does not involve, imply, or express any guaran- Production Editor: Barbara A. Chernow tee or responsibility on the part of the publishers in respect to any International Production Director: Andreas Schabert dosage instructions and forms of applications stated in the book. International Marketing Director: Fiona Henderson Every user is requested to examine carefully the manufacturers’ Director of Sales, North America: Mike Roseman leaflets accompanying each drug and to check, if necessary in consul- International Sales Director: Louisa Turrell tation with a physician or specialist, whether the dosage schedules Vice President, Finance and Accounts: Sarah Vanderbilt mentioned therein or the contraindications stated by the manufac- President: Brian D. Scanlan turers diff er from the statements made in the present book. Such Compositor: Toppan Best-set Premedia Limited examination is particularly important with drugs thatare either rarely used or have been newly released on the market. Every dosage Library of Congress Cataloging-in-Publication Data schedule or every form of application used is entirely at the user’s Yoshioka, Nobutaka, author. own risk and responsibility. The authors and publishers request every Atlas of the facial nerve and related structures / Nobutaka user to report to the publishers any discrepancies or inaccuracies Yoshioka, Albert L. Rhoton, Jr. noticed. If errors in this work are found after publication, errata will p. ; cm. be posted at www.thieme.com on the product description page. Includes index. Some of the product names, patents, and registered designs ISBN 978-1-62623-171-9 (alk. paper) referred to in this book are in fact registered trademarks or propri- I. Rhoton, Albert L., 1932– , author. II. Title. etary names even though specific reference to this fact is not always [DNLM: 1. Facial Nerve—anatomy & histology—Atlases. made in the text. Therefore, the appearance of a name without des- 2. Head—anatomy & histology—Atlases. 3. Neck—anatomy & ignation as proprietary is not to be construed as a representation by histology—Atlases. WL 17] the publisher that it is in the public domain. QP327 612.9’2078—dc23 2014044551

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ffirs03.indd iv 2/10/2015 1:41:06 PM Contents

Preface by Nobutaka Yoshioka...... vii Preface by Albert L. Rhoton, Jr...... ix

Section I Intracranial Region and Skull ...... 1 1 Intracranial Region...... 3 2 Skull: External and Internal Views ...... 7 3 Orbit and Facial Bone ...... 12

Section II Upper Facial and Midfacial Region...... 19 4 Upper Facial and Midfacial Region Overview...... 21 5 Forehead and Orbital Region...... 23 6 Temporal Region...... 32 7 Super fi cial Structures in the Midfacial Region...... 38 8 Maxillary Region...... 49 9 Masseteric Region ...... 56 10 Deep Structures in the Midfacial Region...... 61

Section III Lower Facial and Posterolateral Neck Region ...... 79 11 Lower Facial Region ...... 81 12 Oral Floor and Upper Neck Region ...... 88 13 Posterior Neck and Occipital Region...... 91 14 Lateral Neck Region ...... 102

Index...... 105

Note: Every fi gure shows the left side whenever the unilateral side is shown.

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It has been more than ten years since I fi nished my fellowship Facial reanimation surgery has been my life ’ s work for at the Microneuroanatomy Laboratory at the University of more than 10 years, and with this book, Dr. Rhoton and Florida. I fi rst met Dr. Albert Rhoton at the seventh meeting I had as our goal the creation of an atlas of anatomy of the of the Japanese Society for Skull Base Surgery, held in Hakata, facial nerve illustrated with precisely dissected specimens, Japan, in 1995. I will never forget how deeply impressed I was similar to the beautifully illustrated Pernkopf Anatomy . I by the anatomical illustrations he showed at that meeting. As believe that an atlas of anatomy consisting of specimens is every neurosurgeon now knows, his images detail delicate more understandable than one with illustrations, even if they brain anatomy in a unique way, and it was something that I are delicately drawn. Our appreciation of basic human had never seen before. Then, from Septembr 2003 to August anatomy is not always complete, and a thorough reevaluation 2004, I had an opportunity to study head anatomy at his labo- of the literature supplemented by detailed cadaver dissec- ratory. At that time, I was a board-certifi ed plastic surgeon tions can lead to new insights that may alter our surgical and a board-certifi ed neurosurgeon in Japan. Although I had technique. been working exclusively as a plastic surgeon rather than as Finally, I want to express my appreciation for the patience a neurosurgeon, Dr. Rhoton generously allowed me to study of my children, Aya, Satoshi, Akira, and Jun, while I have been the anatomy of the extracranial region at his laboratory. This immersed in this project and clinical work. I think this book had been my major interest as a plastic surgeon, and I found should be dedicated to the donors of the specimens shown in my research that the qualities of anatomical specimens because only their devotion made this work possible. varied greatly. For example, the quality of silicon injection of the extracranial region diff ered from the intracranial region, Nobutaka Yoshioka, MD, PhD and this concerned me. Fortunately, at Dr. Rhoton’s laboratory I was fi nally able to obtain some good specimens in which the silicon was almost perfectly injected into the extracranial region.

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One of the joys of my professional career has been to work full course of the facial nerve. Each section is fi lled with with Nobutaka Yoshioka, MD, PhD, an outstanding plastic stunning color images of his magnifi cent dissections, and surgeon, on this atlas. My applause and congratulations go to every fi gure is supplemented with a concise, well-focused him for this outstanding book. Michelangelo and da Vinci and description that provides a wealth of information. Surgeons, many great artists pursued cadaveric dissection as a way of particularly neurosurgeons and plastic surgeons, as well as achieving perfection in their art; this beautiful anatomical ENT and head and neck specialists around the world will volume highlights Dr. Yoshioka’ s own passion for perfection. benefi t from this work. Students and trainees will also benefi t Dr. Yoshioka worked in our microsurgery laboratory, where from studying this book cover to cover, while readers with he created precise and accurate dissections of the facial nerve advanced knowledge and experience will fi nd it a useful as a guide to improving the lives of our patients. We are for- reference. tunate to have had Dr. Yoshioka in our laboratory, where he My work with Dr. Yoshioka and other young surgeons from worked night and day to achieve the excellence refl ected in across the globe has been one of the most rewarding aspects the photographs in this book. of my career and a source of many treasured friendships. This In sections, which begin with the skull and intracranial book is a refl ection of this friendship and cooperation. structures, followed by the upper, mid, and lower face and the posterolateral neck, this atlas captures the Albert L. Rhoton, Jr., MD

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Motor root of V Cerebellum Sensory root of V

Vestibulocochlear n. Facial n. (cisternal segment) Trigeminal ganglion

Anterior semicircular canal Greater (superficial) V3 petrosal n. (GSPN) Lesser petrosal n. Posterior semicircular canal Superior tympanic a. Lateral semicircular canal Middle meningeal a. Tympanic cavity Stapes Malleus Incus

Facial n. Chorda tympani

Fig. 1.1. Middle fossa from above. The tegmen tympani and the roof of the internal acoustic meatus have been opened.

The facial nerve contains motor fi bers, which are responsible sublingual glands. The two components merge within the for facial expression, as well as other nerve fi bers involved in meatus. sensation (auricular concha; see Fig. 13.3b), taste (anterior The greater (superfi cial) petrosal nerve (GSPN) is a branch two-thirds of the tongue; see Fig. 1.3 ), and secretory function of the facial nerve and carries parasympathetic fi bers to the (lacrimal gland, submandibular gland, and sublingual gland; pterygopalatine fossa. It emerges within the facial canal of the see Fig. 5.9a and Fig. 12.1 ). temporal bone, close to the geniculate ganglion of the facial The facial nerve emerges from the brainstem at the junc- nerve. It then passes through the bone to appear on the fl oor tion of the pons and medulla. The course of the facial nerve of the middle cranial fossa and runs medially in a shallow may be divided into intracranial, intratemporal, and extra- groove to the foramen lacerum. Passing within the foramen temporal segments. The intracranial segment, known as the lacerum, the greater petrosal nerve enters the pterygoid canal pontine or cisternal segment, spans roughly 25 mm and con- that lies at the base of the pterygoid process. On leaving the nects the facial nerve from its origin to the entrance of the pterygoid canal, the nerve emerges into the pterygopalatine internal acoustic meatus. The intratemporal segment can be fossa and joins the pterygopalatine ganglion (see Fig. 10.15 ). divided into four segments: meatal, labyrinthine, horizontal, The lesser petrosal nerve is a branch of the glossopharyn- and vertical. The facial nerve, accompanied by the vestibulo- geal nerve and carries parasympathetic fi bers to the otic gan- cochlear nerve, enters the temporal bone through the internal glion. The nerve arises in the middle ear and passes on to the acoustic meatus. Initially, there are two separate components, fl oor of the middle cranial fossa through a hiatus in the petrous which are the motor root supplying the muscle of the face part of the temporal bone. The nerve lies in a groove located and the nervus intermedius that contains sensory fi bers con- lateral to that of the greater petrosal nerve and runs toward the cerned with the perception of taste and parasympathetic foramen ovale and then enters the infratemporal fossa through (secretomotor) fi bers to the lacrimal, submandibular, and the foramen ovale to join the otic ganglion (see Fig. 10.12 ).

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Anterior inferior cerebellar a., Facial n., Nervous intermedius, Internal carotid a. Vestibulocochlear n.

V2 Anterior semicircular canal Greater petrosal n. (cut) Cochlea (opened) (GSPN) V3 Tensor tympani m. Geniculate ganglion Middle meningeal a. Posterior semicircular canal Lateral semicircular canal Eustachian tube Facial n. Chorda tympani Chorda tympani

Mandibular fossa (opened)

External acoustic meatus

Fig. 1.2. Middle fossa from above. The mandibular fossa and the roof of external acoustic meatus have been opened.

The trigeminal nerve supplies sensations to the face, mucous tympanic cavity. It draws the handle of the malleus medially, membranes, and other structures of the head. It is the motor and the muscle tenses the tympanic membrane and helps to nerve for the muscles of mastication and contains proprio- damp sound vibrations. The nerve to the tensor tympani ceptive fi bers. It exits the brain by a large sensory root and a muscle is derived from the mandibular division of the tri- smaller motor root emerging from the pons at its junction geminal nerve. with the middle cerebral peduncle. It passes laterally to join The middle meningeal artery, which is a branch of the the trigeminal (gasserian or semilunar) ganglion in the tri- maxillary artery (mandibular segment), enters the middle geminal cave (Meckel’ s cave) close to the apex of the petrous cranial fossa through the foramen spinosum. This artery part of the temporal bone, and then it appears as three major has branches to the trigeminal ganglion and to the tympanic (ophthalmic, maxillary and mandibular) divisions. After cavity (superior tympanic branch). The superior tympanic removing the dura, the maxillary (V2) and mandibular (V3) artery supplies the tensor tympani muscle. An accessory nerves are identifi ed. The ophthalmic and maxillary nerves meningeal artery, which is a branch of the maxillary pass through the lateral wall of the cavernous sinus. The man- artery (mandibular segment), runs through the foramen dibular nerve passes directly to the foramen ovale. ovale into the middle cranial fossa to supply the trigeminal The tensor tympani muscle lies within a bony canal situ- ganglion and the dura lining the fl oor of the middle cranial ated above the Eustachian tube in the anterior wall of the fossa.

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Temporal fascia

Middle fossa dura Anterior semicircular canal Superior petrosal sinus

Lateral semicircular canal Posterior fossa dura Short process of incus Posterior semicircular canal Sigmoid sinus

Facial n. (vertical part) Endolymphatic sac Chorda tympani (blue sheet is in the sac) Meningeal br. of occipital a., Emissary v.

Digastric ridge Digastric m. Facial n. (extratemporal) Occipital a. Auricular br. of posterior auricular a.

Fig. 1.3. Lateral view of the mastoid after mastoidectomy

The mastoid process is a prominence projecting from the Within the facial canal, close to the pyramid, arises the undersurface of the mastoid portion of the temporal bone. nerve to the stapedius muscle. The stapedius is the smallest This process is a point of attachment for the splenius capitis, skeletal muscle in the human body. At just over 1 mm in the longissimus capitis, the digastric posterior belly, and the length, its purpose is to stabilize the smallest bone in the sternocleidomastoid muscles. body, the stapes. This muscle helps to damp excessive sound The chorda tympani is given off just before the stylomas- vibrations and functions when sound is too loud. toid foramen. It is the branch from the nervus intermedius. It The digastric ridge corresponds to the digastric groove contains parasympathetic fi bers going to the submandibular and marks the location of the facial canal just anterior to ganglion and taste fi bers from the anterior two-thirds of the it. This is a ridge of bone just deep or medial to the mastoid tongue. It initially runs within its own canal before entering tip. the tympanic cavity to cross the malleus. It then enters Hypoglossal-facial nerve side-to-end anastomosis without another canal before leaving the temporal bone through the nerve grafting can be performed to cut the facial nerve at the petrotympanic (squamotympanic) fi ssure. point just below the lateral semicircular canal.

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Anterior fossa Internal carotid a. Mucosa of sphenoid sinus Optic n. (with dura) Oculomotor n. Lateral edge of superior orbital fissure Trochlear n. Orbital br. to lacrimal a. (from middle meningeal a.) V1

Foramen rotundum Trigeminal ganglion V2

Middle fossa

V3

Fig. 1.4. The superior orbital fi ssure and trigeminal nerve. The optic canal has been opened, and anterior clinoidectomy has been done.

The trigeminal nerve has three divisions: ophthalmic (V1), mylohyoid, and digastric. These muscles produce elevation, maxillary (V2), and mandibular (V3). The ophthalmic nerve depression, protrusion, retraction, and the side-to-side passes into the orbit through the superior orbital fi ssure. The movements of the mandible. The motor division also maxillary nerve passes into the pterygopalatine fossa through supplies the tensor tympani and tensor veli palatini the foramen rotundum. The mandibular nerve passes into the muscles. infratemporal fossa through the foramen ovale. All divisions The meningo-orbital foramen is located in the lateral wall have meningeal branches. The dura mater is innervated by of the orbit and links the orbit to the cranial cavity. It repre- the meningeal branches mainly from the trigeminal nerves. sents a passage for the artery connecting the orbital branch The motor division of the mandibular nerve supplies of the anterior division of the middle meningeal artery and the muscles of mastication: masseter, temporalis, pterygoid, lacrimal branch of the ophthalmic artery.

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Tympanic part of Petrotympanic fissure temporal bone Vaginal process Stylomastoid foramen Foramen for stylomastoid artery Styloid process (cut) Spine of sphenoid bone Foramen spinosum

Foramen ovale Eustachian tube Carotid canal Sphenopetrosal suture Jugular foramen Emissary foramen Intrajugular process

Foramen lacerum Occipital condyle Petrooccipital fissure

Fig. 2.1. The external surface of the skull base. Close-up view of the stylomastoid foramen.

The facial nerve exits from the stylomastoid foramen and is foramen are the sigmoid sinus and jugular bulb, the inferior supplied by the stylomastoid artery, which usually originates petrosal sinus, the meningeal branches of the ascending pha- from the posterior auricular artery. The stylomastoid artery ryngeal and occipital arteries, the glossopharyngeal, vagus, enters into the skull from the foramen adjacent to the stylo- and accessory nerves with their ganglia, the tympanic branch mastoid foramen. of the glossopharyngeal nerve (Jacobson’ s nerve), the auricu- The foramen ovale allows passage between the middle lar branch (also known as the mastoid branch) of the vagus cranial fossa and the infratemporal fossa of the mandibular nerve (Arnold’ s nerve), and the cochlear aqueduct. The intra- division of the trigeminal nerve, the lesser petrosal branch of jugular process is a small, curved process which partially or the glossopharyngeal nerve, the accessory meningeal branch completely divides the jugular foramen into lateral and medial of the maxillary artery, and some emissary veins. Behind the parts. foramen ovale lies the foramen spinosum, which transmits Behind the foramen spinosum, the bone is raised to form the middle meningeal vessels and meningeal branch of the the spine of the sphenoid to which the sphenomandibular mandibular division of the trigeminal nerve. ligament is attached. The posterior margin here is grooved The jugular foramen is located between the temporal bone and is related to the cartilaginous component of the Eusta- and the occipital bone. The structures that traverse the jugular chian tube (see Fig. 10.18 ).

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Zygomatic arch Supramastoid crest Articular tubercle Mandibular fossa Inferior orbital fissure External acoustic meatus Infratemporal crest Mastoid process Vaginal process Tympanomastoid suture (Drop-off point) (Tympanic part) Mastoid notch (Digastric Groove) Foramen spinosum Stylomastoid foramen Styloid process (cut) Lateral pterygoid plate Carotid canal Foramen ovale Jugular foramen Eustachian tube Pterygoid hamulus Hypoglossal canal Condylar canal Occipital condyle Vomer

Foramen Magnum

Fig. 2.2. Infratemporal fossa. The mandible has been removed.

The digastric muscle is attached to the mastoid notch (digas- above the stylomastoid foramen, where it gives off a branch tric groove) , the anterior end of which indicates the stylo- that joins the facial nerve. The nerve fi nally reaches the mastoid foramen. The tympanomastoid suture is a landmark surface by passing through the tympanomastoid suture. It of facial nerve trunk. The facial nerve (stylomastoid foramen) divides into two branches: one joins the posterior auricular can be identifi ed at 6 to 8 mm medial to the inferior “drop- nerve, while the other innervates the skin of the concha and off ” point of the tympanomastoid suture. a small area of the cranial surface near the mastoid (see Fig. Jacobson ’ s nerve arises from the petrous ganglion of the 13.3 ). glossopharyngeal nerve. It enters the tympanic cavity via the The osseous boundaries of the infratemporal fossa are the inferior tympanic canaliculus and contributes to the tym- posterolateral maxillary surface anteriorly, the lateral ptery- panic plexus. It contains both sensory and parasympathetic goid plate anteromedially, the mandibular ramus laterally, fi bers. The sensory fi bers supply the middle ear. The para- and the tympanic part of the temporal bone and the styloid sympathetic fi bers leave the plexus as the lesser petrosal process posteriorly. The fossa is domed anteriorly by the nerve and enter the otic ganglion. infratemporal surface of the greater sphenoid wing, the site Arnold ’ s nerve originates from the superior ganglion of the of the foramina ovale and spinosum, and posteriorly by the vagus nerve below the jugular foramen. It passes behind the squamous part of the temporal bone. The inferior, posterome- internal jugular vein and ascends through the mastoid cana- dial, and superolateral aspects are open without bony walls. liculus on the lateral wall of the jugular fossa. It traverses the The infratemporal crest is the boundary between the tempo- substance of the temporal bone and crosses the facial canal ral fossa and infratemporal fossa.

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Pterion

Superior temporal line Temporal bone Groove for middle temporal a. Frontozygomatic suture

Greater wing of Supramastoid crest sphenoid bone Suprameatal spine (Henle) Zygomatic bone Articular tubercle Zygomaticofacial foramina External acoustic meatus Mandibular Condylar process Tympanomastoid suture Coronoid process notch Mastoid process

Occipital condyle

Fig. 2.3. Lateral view of the skull with the temporal bone highlighted.

The suprameatal triangle, a depressed area located below the Pterion is the landmark for frontotemporal craniotomy. It anterior part of the supramastoid crest and behind the pos- is the H-shaped region where the four calvarial bones (frontal, terosuperior margin of the external acoustic meatus, marks sphenoid, parietal, and temporal) meet. the deep location of the mastoid antrum. The suprameatal The superior temporal line begins at the zygomatic process spine (the spine of Henle), which locates anterior part of the of the frontal bone and fi rst curves superoposteriorly and suprameatal triangle, approximates the deep site of the tym- then inferiorly and anteriorly to the supramastoid crest. It panic facial nerve segment and the lateral canal. provides attachment for temporal fascia. The zygomaticofacial nerve is a sensory nerve of the cheek The groove for the middle temporal artery, which supplies and one of the two branches of the zygomatic nerve that posterior and upper part of temporalis muscle, is sometimes originated from the maxillary nerve. It comes out to the face prominent on the temporal bone. through the zygomaticofacial foramen. This foramen is some- The base of the temporomandibular ligament is attached times doubled, and this fi gure shows two zygomaticofacial to the zygomatic process of the temporal bone and the articu- foramina. lar tubercle (see Fig. 9.1 ).

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Lambdoid suture

Asterion Inion (External occipital protuberance) Parietomastoid suture

Occipitomastoid suture Inferior nuchal line

Mastoid foramen External occipital crest

Mastoid process External acoustic meatus Condylar canal Mastoid notch Occipital groove Foramen Magnum Mandibular condyle

Occipital condyle

Fig. 2.4. Posterolateral view of the skull.

The mastoid notch (digastric groove), where the digastric over the junction of the lower part of the transverse and muscle is attached, and the occipital groove, where the occip- sigmoid sinuses. ital artery courses on, are parallel grooves on the posterior The external occipital protuberance is a projection of the aspect of the mastoid process. external surface of the occipital squama. It is situated approx- The meningeal branch of the occipital artery and emis- imately at the mid-point of the squama. It provides attach- sary vein penetrate the cranium through the mastoid ment for the medial fi bers of the trapezius muscle. Below this foramen. prominence is a crest that runs inferiorly to the back edge of The asterion located at the junction of the lambdoid, occip- the foramen magnum. This crest, called the external occipital itomastoid, and parietomastoid sutures is usually located crest, provides attachment for the nuchal ligament.

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Frontal crest

Crista galli

Foramina of cribriform plate Sphenoidal ridge Lesser wing of Superior orbital fissure sphenoid bone Optic canal Greater wing of Anterior clinoid process Tuberculum sellae sphenoid bone Sella turcica (Pituitary fossa) Foramen rotundum Groove for middle Carotid groove meningeal artery Dorsum sellae Foramen ovale

Fig. 2.5. Anterior and middle skull base (internal surface).

The sensory innervation of the face is via the three divisions of of the maxillary artery, and an emissary vein from the cavern- the trigeminal nerve: ophthalmic, maxillary, and mandibular. ous sinus to the pterygoid venous plexus pass through the The superior orbital fi ssure lies between the greater and foramen. lesser wings of the sphenoid at the junction of the roof and The ophthalmic nerve supplies the forehead, upper eyelid, lateral wall of the orbit. It transmits the oculomotor nerve, and dorsum of the nose. The maxillary nerve supplies the the trochlear nerve, and the sympathetic fi laments from the lower eyelid, the cheek, the upper lip, the ala of the nose, and internal carotid plexus, the abducens nerve, and the ophthal- part of the temple, the maxillary teeth, and the nasal cavity. mic division of the trigeminal nerve, together with the oph- The mandibular nerve has motor and sensory fi bers. The thalmic veins. It may also transmit the orbital branch of the latter supplies the skin over the mandible, the lower cheek, middle meningeal artery and the recurrent branch of the part of the temple and ear, the lower teeth, the gingival lacrimal artery (see Fig. 3.1 ). mucosa, and the lower lip. The foramen rotundum lies within the greater wing of the The crista galli is the thick crest of bone that projects above sphenoid. It allows communication between the middle the cribriform. The crest is thickest near its base and tapers cranial fossa and the pterygopalatine fossa. The maxillary superiorly. It projects between the two cerebral hemispheres division of the trigeminal nerve passes through the foramen. with the falx cerebri attaching to its posterior margin. The foramen ovale is also in the greater wing of the sphe- The frontal crest is an anterior crest of bone in the midline noid, and it communicates between the middle cranial fossa of the internal surface of the frontal bone. This sharp ridge of above and the infratemporal fossa below. The mandibular bone is a continuation of the converging edges of the sulcus division of the trigeminal nerve, the lesser petrosal branch of for the superior sagittal sinus. The anterior part of the falx the glossopharyngeal nerve, the accessory meningeal branch cerebri attaches to the ridge.

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Frontal bone Fossa for lacrimal gland Frontonasal suture Sphenofrontal suture Superior orbital fissure Meningo-orbital foramen Frontomaxillary suture Frontozygomatic suture Optic canal Greater wing of sphenoid bone Sphenozygomatic suture Internasal suture

Inferior orbital fissure Zygomatico-orbital foramen Infraorbital sulcus (groove)

Fig. 3.1. Anterior view of the orbit.

The inferior orbital fi ssure lies at the junction of the lateral foramina on the orbital surface of the zygomatic bone. When wall and the fl oor of the orbit. Through this fi ssure pass the one foramen is present, the zygomatic vessels and nerve enter infraorbital and zygomatic branches of the maxillary division and then branch within the bone to exit diff erent foramina as of the trigeminal nerve and accompanying vessels. the zygomaticofacial and zygomaticotemporal vessels and The infraorbital nerve is the terminal branch of the maxil- nerve. The zygomaticotemporal nerve provides sensation to lary nerve. It courses along the orbital fl oor in the infraorbital the temporal skin, and the zygomaticofacial nerve provides sulcus (groove) into a canal and onto the face at the infraor- sensation to the skin over the prominence of the cheek. bital foramen. Meningo-orbital foramen (lacrimal foramen) is located in The zygomatic nerve arises from the maxillary nerve in the greater wing of the sphenoid, anterior to the tip of the the pterygopalatine fossa and passes through the inferior superior orbital fi ssure, and is the source of an anastomosis orbital fi ssure to course along the lateral wall of the orbit, between the lacrimal artery and the orbital branch of the where it divides into zygomaticofacial and zygomaticotempo- middle meningeal artery. This foramen is present in approxi- ral branches. The branches enter the zygomatico-orbital mately 50% of Caucasian people.

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Meningeal br. to falx Crista galli Crista galli Anterior ethmoidal groove Anterior ethmoidal a.(to the nasal cavity) Cribriform plate Anterior ethmoidal a.(from the orbit) Posterior ethmoidal groove Falx a c

Supraorbital foramen

Frontal bone Meningo-orbital foramen Frontal notch

Anterior ethmoidal foramen Superior orbital fissure Posterior ethmoidal foramen Optic canal Optic strut Orbital plate (Ethmoid bone) Nasal bone Foramen rotundum Inferior orbital fissure Anterior lacrimal crest Lacrimal fossa Infraorbital sulcus (groove) Maxilla Posterior lacrimal crest Zygomaticofacial foramen

b

Fig. 3.2a-c. (a) Superior view of the cribriform plate. (b) Anteromedial view of the orbit. (c) Superior view of the ethmoid bone.

The supraorbital foramen, the frequency of which is 20 to through the posterior ethmoidal foramen to enter the nose. It 30%, is the passage mainly for the supraorbital nerve, espe- supplies the sphenoidal sinus and the posterior ethmoidal air cially its lateral branch, one of the medial branches, and its cells. The view of the ethmoid bone from above ( Fig. 3.2c ) concomitant small artery (see Fig. 5.3b). The main trunk of shows anterior and posterior ethmoidal grooves for the same the supraorbital artery generally passes under the supraor- nerves and vessels, which are converted into foramina by bital notch or just below the supraorbital rim. The supraor- articulation with frontal bone. It is important that lowest point bital notch also transmits the supraorbital nerve. The frontal of the cribriform plate (lowest point of the anterior skull base) notch, which is medial to the supraorbital notch, transmits is generally below the anterior and posterior ethmoidal the supratrochlear nerve and artery. foramen on the medial orbital wall (Fig. 3.2a ). The optic canal lies within the lesser wing of the sphenoid The fossa for the lacrimal sac is formed by the lacrimal and transmits the optic nerve and ophthalmic artery. incisure on the maxilla and a matching groove on the lacrimal The anterior and posterior ethmoidal foramina for the same bone. When the adjacent grooves are combined, they form a nerves and vessels are situated at the medial wall. The anterior fossa and a canal that houses the lacrimal sac and transmits ethmoidal nerve exits the orbit through the anterior eth- the beginning of the lacrimal duct toward the nasal cavity. moidal foramen and enters the anterior cranial fossa. It runs The cribriform plate is the horizontal plate of the ethmoid into the roof of the nose through small slits lying on each side bone perforated with numerous foramina for the passage of of the crista galli. The posterior ethmoidal nerve exits the orbit the olfactory nerve fi laments from the nasal cavity.

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b

Supraorbital foramen

Nasal bone Fossa for lacrimal gland

Nasal septum Middle nasal concha

Anterior nasal spine Inferior nasal concha Infraorbital foramen Intermaxillary suture

Zygomatic arch Coronoid process

a

Fig. 3.3a,b. (a) Anteroinferior view of the skull. (b) Anteroinferior view of the maxilla after removing the anterior and posterior sinus walls to show the foramen rotundum.

The infraorbital foramen lies below the infraorbital rim. The the infratemporal fossa and posterior to the maxilla on each infraorbital branch of the maxillary nerve and infraorbital side of the skull, located between the pterygoid process and vessels pass through the foramen. the maxillary tuberosity, close to the apex of the orbit. It is The anterior and posterior walls of the left maxillary sinus the indented area medial to the pterygomaxillary fi ssure have been opened to see the pterygopalatine fossa and leading into the sphenopalatine foramen. It communicates foramen rotundum (Fig. 3.3b ). Black string is passing from with the nasal and oral cavities, the infratemporal fossa, the the foramen rotundum to the infraorbital foramen. The ptery- orbit, the pharynx, and the middle cranial fossa through eight gopalatine fossa is a cone-shaped paired depression deep to foramina (see Fig. 8.4 ).

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Foramen ovale Pterygoid hamulus

Choana Vomer Lesser palatine foramen Lesser palatine foramen Posterior nasal spine

Greater palatine foramen Horizontal plate of palatine bone

Transverse palatine suture

Palatine process of Median palatine suture maxillary bone

Infraorbital foramen Incisive fossa and canal

Fig. 3.4. Inferior view of the palatine bone.

The nasopalatine nerve, which is a branch of the pterygopala- as the incisor teeth. It supplies the gums, the mucous tine ganglion, enters the nasal cavity through the sphenopala- membrane, and the glands of the hard palate, and it com- tine foramen and runs obliquely downward and forward on municates in front with the terminal fi laments of the naso- the nasal septum. It terminates as the incisive nerve, which palatine nerve. passes through the incisive canal with an accompany artery The lesser palatine nerve passes through the greater pala- onto the hard palate to supply oral mucosa around the inci- tine canal and onto the palate at the lesser palatine foramen. sive papilla. It communicates with the corresponding nerve It runs backward to supply the soft palate. It also has nasal of the opposite side and with the greater palatine nerve. branches that innervate the nasal cavity. The greater palatine nerve is a branch of the pterygopala- The pterygoid hamulus is the laterally defl ected hook of tine ganglion that carries both general sensory and parasym- bone at the inferior end of the medial pterygoid plate. It pathetic fi bers. It passes through the grater palatine canal serves a pulley-like function for the tendon of the tensor veli and onto the hard palate at the greater palatine foramen. palatini muscle and serves as the attachment for the ptery- It passes forward in a groove in the hard palate, nearly as far gomandibular raphe.

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Supraorbital foramen Glabella Frontonasal suture Nasal part of frontal bone Frontal notch

Nasomaxillary suture Frontomaxillary suture Superior orbital fissure Frontal process of maxilla

Inferior orbital fissure

Infraorbital foramen Piriform aperture

Canine fossa

Canine eminence

Incisive fossa

Incisive fossa Mental foramen

Mental protuberance

Fig. 3.5. Anterior view of the skull.

The orbicularis oculi muscle arises from the nasal part of the zygomaticotemporal suture. The zygomaticus minor muscle frontal bone, the frontal process of the maxilla, and the medial also arises from the zygomatic bone, just in front of the origin palpebral ligament. of zygomaticus major. The corrugator supercilii muscle arises from the medial The canine eminence overlies the root of the canine tooth. end of the supraorbital ridge on the frontal bone. It separates the anterior surface of the maxilla into two The procerus muscle arises from the nasal bone and the concave areas: a shallow, incisive fossa in front and a deeper, lateral nasal cartilage. canine fossa behind. The levator anguli oris muscle arises The nasalis and depressor septi muscle arise from the from the canine fossa of the maxilla, immediately below the maxilla in the region overlying the root of the lateral incisor infraorbital foramen. and canine tooth. The supraorbital foramen, the infraorbital foramen, and The levator labii superioris muscle arises from the maxilla the mental foramen are found approximately in line at the inferior orbital rim, above the infraorbital foramen. vertically. The levator labii superioris alaeque nasi muscle arises from The piriform aperture (anterior nasal aperture) is a heart- the frontal process of the maxilla. or pear-shaped bony nasal opening in the skull. The zygomaticus major muscle arises from the lateral surface of the zygomatic bone, just in front of the

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Condylar head

Coronoid process

Condylar neck

Retromolar fossa

External oblique line

Incisive fossa Mental foramen

Mental tubercle Mental protuberance

Fig. 3.6. Anterior view of the mandible.

The depressor labii inferioris muscle arises from the mandible There are fi bers by which the orbicularis oris muscle is just in front of the mental foramen. connected with the maxilla and the septum of the nose above The depressor anguli oris muscle arises from an extensive and with the mandible below. area around the external oblique line of the mandible. A distinct prominence, the mental protuberance, lies at the The platysma muscle arises from the superfi cial fascia of inferior margin in the midline of the mandible. On each side the upper part of the thorax. It runs up to the neck to insert of the protuberance are the mental tubercles. Above the into the lower border of the body of the mandible, the skin of mental protuberance lie a shallow depression called the inci- the lower part of the mouth, and the mimetic muscles around sive fossa. The mental foramen is in the region of the premo- the angle of the mouth. lar teeth. The mental nerve, which originated from the inferior The mentalis muscle originates from the incisive fossa of alveolar nerve, and the accompanying vessels pass onto the the mandible. face through this foramen. The buccinator muscle is attached to the alveolar margin of the maxilla and mandible in the region of the molar teeth.

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Coronoid process Condyle Head Mandibular notch Pterygoid fovea Condyle Neck

Temporal crest Lingula Mandibular foramen Ramus

Mylohyoid groove (groove for mylohyoid n.) Sublingual fossa Mylohyoid line Angule Body Submandibular fossa

Fig. 3.7. Posterolateral view of the mandible.

The temporalis muscle inserts onto the apex, the anterior and The medial pterygoid muscle inserts into the rough- posterior borders, and the medial surface of the coronoid ened surface of the angle of the mandible on its medial process. The insertion extends down the anterior border of aspect. the ramus near the third molar tooth. Many of the fi bers have The mandibular foramen, through which the inferior alve- a tendinous insertion. The temporal crest is a ridge along olar nerve and vessels pass into the mandibular canal, lies in anteromedial aspect of the coronoid process and upper ramus the center of the medial surface of the ramus. of the mandible into which the temporalis muscle inserts. A bony process, the lingula, extends from the anterosupe- A small depression, the pterygoid fovea, is a site of attach- rior surface of the foramen and gives attachment to the sphe- ment of the lower head of lateral pterygoid muscle. It is situ- nomandibular ligament. ated on the anterior part of the neck of the condyle. The upper The mylohyoid groove is where the mylohyoid nerve runs head of the lateral pterygoid muscle insets into the capsule down from the posteroinferior surface of the mandibular and medial aspect of the articular disc of the temporoman- foramen. dibular joint. The sublingual gland lies adjacent to the sublingual fossa. The masseter muscle inserts into the lateral surface of the The submandibular fossa is a depression for the submandibu- angle, ramus, and coronoid process of the mandible. lar gland.

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c04.indd 19 2/10/2015 1:39:39 PM c04.indd 20 2/10/2015 1:39:39 PM Upper Facial and Midfacial 4 Region Overview

Temporoparietal fascia (Superficial temporal fascia) Superficial temporal a.

Auriculotemporal n.

Zygomatico-orbital a.

Orbicularis oculi m.

Levator labii superioris m. Zygomaticus minor m. Zygomaticus major m. Parotid fascia

Levator anguli oris m.

Buccal fat pad Facial a.

Risorius m.

Platysma

Fig. 4.1. Lateral view of the face. The superfi cial musculoaponeurotic system (SMAS) is shown after removing the skin.

In the scalp, the superfi cial musculoaponeurotic system vary. Some mimetic muscles, such as the levator labii superioris (SMAS) is represented by the galea aponeurotica, which then and the zygomaticus major, are almost always present, whereas splits to ensheath the frontalis, the occipitalis, the procerus, the risorius muscle is relatively uncommon. Moreover, there is a and some of the periauricular muscles. In the temporal region, striking degree of variability in their size and shape from indi- the SMAS, the superfi cial temporal fascia, and the temporo- vidual to individual. Many of the mimetic muscles are attached parietal fascia are synonymous. In the cheek, the SMAS is to the facial skeleton and insert into the skin. Mimetic muscles represented by the parotid fascia as a remnant of the primi- cause movement of the facial skin to refl ect emotions. tive platysma. The SMAS is relatively thick over the parotid The risorius muscle does not arise from bone but origi- gland. However, it thins considerably, thereby making it dif- nates from the connective tissue overlying the parotid gland. fi cult to dissect medially. The SMAS is continuous with the The muscle runs horizontally across the face to insert into the platysma below and extends to the zygoma above. The precise skin at the corner of the mouth. It pulls the corner of the anatomy of the SMAS, its regional variations, and even the mouth laterally, as in grinning. existence of the SMAS are still debated. The facial artery runs superfi cially above the SMAS layer The facial nerve and its branches are under the SMAS. The at the buccal (on the buccinator muscle) and nasolabial (on frequency of appearance of certain mimetic muscle is known to the orbicularis oris muscle) region.

c04.indd 21 2/10/2015 1:39:39 PM 22 II Upper Facial and Midfacial Region

Parietal br. of superficial temporal a. Frontalis m. Galea aponeurotica Frontal br. of superficial temporal a. Superior auricular m. Auriculotemporal n. Corrugator supercilii m. Orbicularis oculi m. Occipitalis m. Posterior auricular v. Zygomatico-orbital a. Occipital a. Superficial temporal a., v. Posterior auricular m. Temporal brs.

Zygomatic br. Greater occipital n. Transverse facial a. Levator labii superioris m. Splenius capitis m. Parotid duct Posterior auricular a. Zygomaticobuccal brs. Parotid gland Levator anguli oris m. Zygomaticus major m. Masseter m. (with fascia) Orbicularis oris m. Lesser occipital n. Modiolus Sternocleidomastoid m. Buccinator m. Accessory n. Marginal mandibular br. Great auricular n. Facial a., v. Cervical br. Depressor anguli oris m. External jugular v. Depressor labii inferioris m. Platysma m.

Fig. 4.2. Lateral view of the face. The superfi cial musculoaponeurotic system (SMAS) has been removed to show the facial nerve branches. Every mimetic muscle and part of the temporoparietal fascia and galea are preserved.

Mimetic muscles, with the exception of the buccinator, the process of the temporal bone. It divides into anterior levator anguli oris, and the mentalis, are innervated from (frontal) and posterior (parietal) branches. A transverse facial their deep surface by the facial nerve branches. These muscles artery arises from the superfi cial artery within the parotid are located in the deepest layer among the mimic muscles and gland and crosses the masseter muscle above the parotid are innervated from their superfi cial surface. The superior duct. auricular muscle arises from the temporoparietal fascia and The superfi cial temporal vein is formed above the zygo- inserts into the upper part of the cranial surface of the auricle. matic arch by the union of anterior and posterior tributaries. It is innervated by the temporal branch of the facial nerve. It The superfi cial temporal vein then enters the substance of the displaces the auricle superiorly. parotid gland. It unites fi rst with the middle temporal vein The facial artery and vein are independently running and then with the maxillary vein to form the retromandibular obliquely from the mandibular angle toward the medial vein in the gland. When the superfi cial temporal vein is canthus. The superfi cial temporal artery is one of the termi- poorly developed or, as occasionally happens, is absent, the nal branches of the external carotid artery. The artery posterior auricular vein usually compensates for it, as shown passes upward toward the scalp, crossing the zygomatic in this fi g u r e .

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Lateral br. of supraorbital n.

Frontalis m.

Medial brs. of supraorbital n. Temporoparietal fascia

Frontal br. of superficial temporal a.

Auriculotemporal n. Supraorbital v. Superficial brs. of Orbicularis oculi m. supraorbital a. and supratrochlear a. Zygomatico-orbital a.

Fig. 5.1. The frontotemporal region. The skin has been removed to show the frontalis muscle and galeal layer.

The galea aponeurotica extends from the external occipital The forehead sensation is supplied by the supraorbital and protuberance and supreme nuchal lines to the eyebrows. supratrochlear nerves. The supratrochlear nerve provides The aponeurotica is continuous laterally with the temporo- sensation to the medial side of the forehead. The supraorbital parietal fascia overlying the temporal fascia. The galea nerve has medial (superfi cial) and lateral (deep) branches. aponeurotica contains the occipitofrontal muscle. Each frontal The former provides sensation to the forehead region, and the belly of the frontalis muscle arises from the anterior margin latter supplies sensation to the frontoparietal region. The of the galea aponeurotica and passes forward to merge with lateral branch penetrates the frontalis muscle and galeal layer the orbicularis oculi muscle. The main function of the occipi- at the forehead, usually above the hairline. tofrontalis muscle is to elevate the eyebrows to produce The superfi cial temporal artery and vein run on the galeal transverse furrows of the forehead. This frontalis muscle is aponeurotica. The superfi cial branches of the supraorbital innervated by the temporal branch of the facial nerve. and supratrochlear arteries communicate with the superfi cial temporal artery on the galeal layer.

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Communicating br. Frontal br. of superficial Deep br. of temporal a. supraorbital a. Lateral br. of supraorbital n. Pericranium Superficial br. of supraorbital a. Temporoparietal fascia

Orbicularis oculi m.

Temporal fascia

Temporal brs. of facial n.

Fig. 5.2. The frontotemporal region. The frontalis muscle has been separated from the orbicularis oculi muscle and lifted.

The temporal branches of the facial nerve generally course nerve to the frontoparietal scalp. There is a loose areolar along the undersurface of the temporoparietal fascia and in tissue between the galea aponeurotica and the pericranium the subgaleal fat pad. The temporoparietal fascia (galea) and that allows scalp mobility. its extension frontalis muscle are elevated to leave the tem- The arterial communication between the superfi cial tem- poral branches of the facial nerve on the temporal fascia in poral artery and the deep branch of the supraorbital artery this specimen. is shown. The deep (lateral) division of the supraorbital nerve runs The pericranium is continuous with the temporal fascia cephalad across the lateral forehead between the frontalis in the temporal region. muscle and galeal layer and the pericranium as the sensory

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Lateral br. of supraorbital n. Deep brs. Medial br. of supraorbital n. Supraorbital a. b Superficial br.

Pericranium (with loose areolar tissue)

Lateral br. of supraorbital n.

Pericranial v.

Supratrochlear a. Supraorbital a. (Deep br.) (Deep brs.) Corrugator supercilii m. Supraorbital v. (separated to leave the Supraorbital n. attachment) (Medial br.) Supratrochlear a., n., v. Supraorbital n. to skin(cut)

Rt. Eye Frontalis m.

a

Fig. 5.3a,b. (a) The supraorbital region. The forehead skin and frontalis muscle have been refl ected inferiorly. (b) Medial view of the supraorbital region.

The frontalis muscle has been refl ected inferiorly. The attach- The main trunk of the supraorbital and supratrochlear arter- ment of the corrugator supercilii muscle is shown at the ies course below the orbital roof and divide near or above the medial side on the frontal bone. supraorbital rim into superfi cial and deep branches ( Fig. 5.3b ) . The supraorbital nerve has two divisions: a superfi cial The superfi cial branch run in the galea-frontalis layer of the (medial) division that passes shortly over the pericranium scalp, and the deep branches ascend in and supply the pericra- and then pierces the frontalis muscle, providing sensory nium. The deep branch of the supratrochlear artery generally supply to the forehead skin, and a deep (lateral) division that penetrates the corrugator supercilii muscle before reaching the runs cephalad across the lateral forehead between the galea pericranium. The forehead pericranium is supplied dominantly aponeurotica and the pericranium as the sensory nerve to the from the deep branches of the supraorbital artery. frontoparietal scalp. The deep division consistently courses Both the deep veins from the pericranial layer and the super- approximately 1 cm medial to the superior temporal line, fi cial veins from the galea-frontalis layer empty into a trans- which is the attachment of the temporal fascia. It can be verse channel in the supraorbital area that courses between the identifi ed at the level of hair line just beneath the galea apo- galea-frontalis layer and the pericranium. This transverse neurotica. In contrast, the supratrochlear nerve has only a venous trunk joins the supratrochlear veins on the medial side superfi cial branch. and the superfi cial temporal veins on the lateral side.

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Levator palpebrae Ophthalmic a. superioris m. Supraorbital a. Frontal n. Superior oblique m. Lacrimal a. Superior rectus m. Lacrimal n.

Nasociliary n.

Superior ophthalmic v. Ophthalmic a.

Optic n. Trochlear n.

Fig. 5.4. Superior view of the orbit without orbital fat. Extraocular muscles above the optic nerve have been retracted laterally to show the ophthalmic artery.

The ophthalmic nerve passes along the lateral dural wall The nasociliary nerve passes into the orbit through the of the cavernous sinus and gives off three main branches superior orbital fi ssure and runs forward and medially across just before the superior orbital fi ssure. The three branches are the optic nerve. The nasociliary nerve gives rise to the sensory the lacrimal nerve, the frontal nerve, and the nasociliary branches to the ciliary ganglion, the long ciliary branches, and nerve. the posterior ethmoidal nerves. The posterior ethmoidal nerve The lacrimal nerve enters the orbit through the superior leaves the orbit through the posterior ethmoidal foramen to orbital fi ssure. It passes forward along the lateral wall of the enter the nose. It supplies the sphenoidal sinus and the poste- orbit on the superior border of the lateral rectus muscle. It rior ethmoidal air cells. Near the anterior ethmoidal foramen, passes through the lacrimal gland to supply the conjunctiva the nasociliary nerve divides into its terminal branches: the and the skin of the lateral part of the upper eyelid. The lacri- anterior ethmoidal and the infratrochlear nerves. mal nerve communicates with the zygomaticotemporal The ophthalmic artery arises from the internal carotid branch of the maxillary nerve. The parasympathetic fi vers to artery, and it traverses the optic canal below the optic nerve. the lacrimal gland are conveyed via the zygomatic branch of It passes from the lateral side to the medial side immediately the maxillary nerve. beneath the superior rectus muscle. Then, it runs with the The frontal nerve enters the orbit through the superior nasociliary nerve and passes between the superior oblique orbital fi ssure and passes forward on the levator palpebrae and medial rectus muscles. The ophthalmic artery terminates superioris muscle. It divides into the supraorbital and the near the medial canthus by dividing into the dorsal nasal and supratrochlear nerves. the supratrochlear arteries.

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Supraorbital a., n.

Supraorbital n.

Superior ophthalmic v. Supratrochlear n.

Lacrimal gland

Levator palpebrae Ophthalmic a. superioris m.

Superior rectus m. Nasociliary n. Lacrimal a.

Lacrimal n. Superior oblique m.

Lateral rectus m.

Frontal n.

Superior ophthalmic v.

Periorbita Recurrent meningeal a.

Fig. 5.5. Superior view of the orbit without orbital fat.

The supraorbital nerve emerges from the orbit through the The anterior ethmoidal nerve exits the orbit through supraorbital notch and foramen (only some of its branches the anterior ethmoidal foramen. It enters the anterior always pass through whenever there is a foramen [see Fig. cranial fossa where the cribriform plate of the ethmoid bone 5.3]). It supplies most of the forehead and upper lid, except meets the orbital part of the frontal bone. It then runs into for its lateral region. the roof of the nose through a small foramen at the side of The supratrochlear nerve emerges from the orbit above the the crista galli. The anterior ethmoidal nerve terminates trochlea and gives a descending branch to the infratrochlear on the face as the external nasal nerve to supply the skin of nerve. It ascends onto the medial part of the forehead through the nasal tip. the frontal notch. The ophthalmic artery gives rise to four branches The nasociliary nerve divides into the anterior ethmoidal within the orbit to supply the face: the lacrimal artery, and the infratrochlear nerves near the anterior ethmoidal the supraorbital artery, the supratrochlear artery, and the foramen. dorsal nasal artery. The lacrimal artery reaches the skin The infratrochlear nerve passes forward along the medial through the upper lateral corner of the orbit and supplies wall of the orbit below the pulley of the superior oblique the lateral part of the eyelids. Within the orbit, the lacrimal muscle. It passes above the medial palpebral ligament to artery gives off zygomaticofacial and zygomaticotemporal reach the side of the nose to supply the skin of the medial arteries. aspect of the upper eyelid.

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Frontalis m.

Procerus m. Oblique head (corrugator supercilii m.) Corrugator supercilii m. Transverse head Supratrochlear a. (Deep brs.)

Medial br. of supraorbital n. Supraorbital a. (Deep brs.)

Lateral br. of Lateral br. of supraorbital n. supraorbital n.

Pericranium (with loose areolar tissue)

Fig. 5.6. The supraorbital region. The skin and frontalis muscle have been refl ected.

The corrugator supercilii muscle originates from the medial courses approximately 1 cm medial to the superior temporal end of the supraorbital ridge on the frontal bone, deep to the line. orbicularis oculi muscle. It passes upward and outward The deep branches of the supratrochlear and supraorbital through the orbicularis oculi muscle to insert into the skin arteries, which supply the pericranium, and the medial of the middle of the eyebrow. This muscle has two branches of the supraorbital nerve, penetrate the corrugator muscle bellies: a transverse head and an oblique head. This supercilii muscle. muscle produces vertical ridges above the bridge of the nose The scalp consists of fi ve layers: the skin, the connective when frowning by drawing the eyebrow downward and tissue, the galea (aponeurosis), the loose areolar tissue, and inward. the pericranium. The fi rst three layers are bound together as The frontalis muscle mingles with the corrugator supercilii a single unit. This unit can move along the loose areolar tissue and orbicularis oculi muscles. The medial fi bers of frontalis over the pericranium, which is adherent to the calvaria. The muscle are continuous with procerus muscle. pericranium is the external periosteum that covers the outer The lateral branch of the supraorbital nerve, which surface of the skull. supplies the frontoparietal scalp, courses obliquely along The pericranial fl ap consists of the pericranium and loose the superior temporal line on the pericranium with areolar tissue. The main blood supply to the fl ap is from the concomitant artery. The lateral division consistently deep branches of the supratrochlear and supraorbital vessels.

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Supratrochlear n. Supratrochlear a. Frontal br. of superficial temporal a. Corrugator supercilii m. Procerus m. Supratrochlear v.

Dorsal nasal a. Zygomatico-orbital a. Infratrochlear n. Palpebral part Angular v. Orbicularis oculi m. Angular a. Orbital part Temporal br. of facial n. Nasalis m. Zygomaticobuccal br. Nerve to nasalis m. to orbicularis oculi m. Levator labii superioris Upper zygomatic br. alaeque nasi m. of facial n. Levator labii superioris m. Facial v. Lateral nasal a. Transverse facial a. Inferior palpebral br.(V) Zygomaticus minor m. Zygomaticus major m. Zygomaticobuccal br. of facial n.

Fig. 5.7. The orbital region. The skin has been removed.

The temporal branch of the facial nerve does not always reach The levator labii superioris alaeque nasi muscle arises from the corrugator supercilii muscle, while the zygomaticobuccal the frontal process of the maxilla. This inserts into the skin branch (see Fig. 7.5 ) usually reaches the corrugator supercilii and the greater nasal cartilage of the nose and into the skin and procerus muscles. and muscle of the upper lip. It elevates the upper lip and The lower orbicularis oculi, zygomaticus major, levator dilates the nostril. anguli oris, zygomaticus minor, risorius, levator labii superi- The infratrochlear nerve is a branch from the nasociliary oris, levator labii superioris alaeque nasi, corrugator superci- nerve. It supplies the skin over the bridge of the nose and at lii, procerus, nasalis, and depressor septi muscles are the medial corner of the upper eyelid. It leaves the orbit below innervated by the zygomaticobuccal branches. the trochlea. The lower orbicularis oculi muscle is generally innervated The dorsal nasal artery is one of the terminal branches of from its inferomedial side by one or two zygomaticobuccal the ophthalmic artery. It accompanies the infratrochlear branches. nerve and emerges between the trochlea of the superior The levator labii superioris muscle arises from the maxilla oblique muscle and the medial palpebral ligament and sup- at the infraorbital rim, above the infraorbital foramen. Some plies the upper part of the nose. It anastomoses with the of the fi bers pass downward to insert into the skin overlying angular artery of the facial artery. the upper lip. Other fi bers merge with those of orbicularis oris muscle. It elevates the upper lip.

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Pericranium Supratrochlear a., v., n. Supraorbital a., v., n. Corrugator supercilii m. (oblique head) Corrugator supercilii m. Orbital septum (transverse head) Orbicularis oculi m. Tarsus of upper lid (orbital part) Angular v. Superior palpebral a. Procerus m. Dorsal nasal a. Medial palpebral ligament Orbicularis oculi m. (lacrimal part) Angular v. Tarsus of lower lid Levator labii superioris Inferior palpebral a. alaeque nasi m. Nasalis m. Orbicularis oculi m.

Fig. 5.8. The orbital region. The mimetic muscles have been cut and partially removed to leave their attachments.

The procerus muscle arises from the nasal bone and the passes behind the lacrimal sac where some fi bers insert into upper lateral nasal cartilage and reaches into the skin between the lacrimal fascia. The lacrimal part dilate the lacrimal sac, the eyebrows. It produces transverse wrinkles over the bridge thereby aiding the fl ow of tears into the sac. of the nose. The upper orbicularis muscle is innervated by temporal The orbicularis oculi muscle is composed of three parts: the branches, and the lower orbicularis muscle is innervated by orbital, the palpebral, and the lacrimal. The muscle is a sphinc- the zygomatic and zygomaticobuccal branches. ter of the eyelids. The orbital part is the largest and arises from The lacrimal nerve is a small branch of the ophthalmic the nasal part of the frontal bone, the frontal process of the nerve. It emerges from the upper lateral margin of the orbit maxilla, and the medial palpebral ligament. The fi bers pass to supply the lateral part of the upper eyelid. around the orbit in concentric loops. The orbital part is involved The supraorbital, the supratrochlear, the dorsal nasal, and in forced closure. The palpebral part is the central part and is the superior and inferior medial palpebral arteries are the confi ned to the eyelids. It arises from the medial palpebral liga- branches of the ophthalmic artery. The superior and inferior ment and runs across the eyelids to insert into the lateral pal- lateral palpebral arteries are the branches from the lacrimal pebral ligament. The palpebral part closes the eyelids gently in artery. The eyelids derive their blood supply from the medial involuntary or refl ex blinking. The palpebral part is divided and lateral palpebral arteries. The supraorbital, supratroch- into three parts: the pretarsal, the preseptal, and the ciliary lear, and angular veins form the superior ophthalmic vein in part. The lacrimal part arises from the lacrimal bone and the orbit.

c05.indd 30 2/10/2015 1:39:51 PM 5 Forehead and Orbital Region 31

Hiatus semilunaris Accessary maxillary ostium Inferior concha Orifice of nasolacrimal duct

b

Supratrochlear n.

Supratrochlear a. Trochlea Lacrimal gland (orbital part) Infratrochlear n. Superior medial palpebral a. Dorsal nasal a. Medial palpebral ligament lacrimal canaliculus Inferior medial palpebral a. Lacrimal sac

Inferior oblique m.

Nasolacrimal duct Periorbita

Levator labii External nasal a. superioris m. a

Fig. 5.9a,b. (a) The orbital region. The lacrimal apparatus has been exposed. (b) Medial view of the lateral nasal wall.

The lacrimal apparatus consists of lacrimal gland, the lacri- The lacrimal sac lies adjacent to the lacrimal groove in the mal canaliculi, the lacrimal sac, and the nasolacrimal duct. anterior part of the medial wall of the orbit. The sac is bounded The lacrimal gland is divided into two parts: orbital and anteriorly by the anterior lacrimal crest of the maxilla and palpebral. The orbital is larger and lies in a fossa in the frontal posteriorly by the posterior lacrimal crest of the lacrimal bone. The innervation of the lacrimal gland is associated with bone. pterygopalatine ganglion. Postganglionic parasympathetic The nasolacrimal duct passes downward from the lacrimal fi bers pass into the maxillary nerve and run with its zygo- sac to the anterior portion of the inferior meatus on the matic branch into the orbit. They join the lacrimal nerve, lateral wall of the nose. The duct lies in a bony canal and derived from the ophthalmic nerve, to reach the lacrimal produces a ridge in the medial wall of the maxillary sinus. gland. Sensory fi bers associated with the gland are derived The shape and position of the opening of the nasolacrimal from the lacrimal nerve. duct into the inferior meatus varies (Fig. 5.9b ).

c05.indd 31 2/10/2015 1:39:52 PM 6 Temporal Region

Zygomatico-orbital a.

Superior auricular a.

Temporal br. to superior auricular m. (blue rubber under it) Superficial temporal a., v. Auriculotemporal n.

Subgaleal fat pad Temporal brs. of Temporal br. of facial n. facial n.(anterior br.) (posterior br.) Transverse facial a. (The masseteric fascia has been opened) Zygomatic br. Parotid gland of facial n.

Fig. 6.1. The temporal region. A part of the temporoparietal fascia has been removed to show the temporal branches.

The temporal branches and communication branches are The zygomatico-orbital artery is a constant branch from shown. The temporal branches of the facial nerve leave the the superfi cial temporal artery to the orbicularis oculi muscle. parotid gland immediately inferior to the zygomatic arch. The The superior auricular artery is a branch from the super- nerve provides motor innervation to the frontalis, to the fi cial temporal artery, and it runs onto the upper part of the upper orbicularis oculi muscles, and occasionally, to the cor- helix. rugator muscle. There are 3 to 5 temporal branches and the The transverse facial artery is shown after opening the most auricular sided (blue rubber under it) branch innervates masseteric fascia. The zygomatic branches are also under this the superior auricular muscle. The other branches innervate fascia and run forward with the artery. the frontalis and upper orbicularis muscles. The superfi cial temporal vein runs superfi cially on the The auriculotemporal nerve ascends on the side of the superfi cial temporal artery in front of the auricle and tempo- head with superfi cial temporal vessels. It supplies the skin of ral region. However, the artery runs superfi cially on the vein the temple and the upper part of the auricle. in the vertex region (see Fig. 13.2a ).

c06.indd 32 2/10/2015 1:39:55 PM 6 Temporal Region 33

Frontal branch of Superior auricular m. superficial temporal a.

Frontalis m. Superficial temporal a., v. Auriculotemporal n. Zygomatico-orbital a. Orbicularis oculi m.

Subgaleal fat pad

Temporal br. of facial n.

Parotid gland

Fig. 6.2. The temporal region. The temporal branches and their innervation to the frontalis and orbicularis oculi muscles are shown.

The temporal branches entering the frontalis muscle and three rami with numerous twigs, entering deeply into the the upper orbicularis oculi muscle are shown (blue rubbers lateral end of orbicularis oculi muscle and the frontalis under branches) after removing a part of the temporoparietal muscle. The temporal branches of the facial nerve generally fascia. The temporal branches of the facial nerve travel in the run below the frontal branch of the superfi cial temporal subgaleal fat pad. The temporal branches divide into mean artery.

c06.indd 33 2/10/2015 1:39:56 PM 34 II Upper Facial and Midfacial Region

Temporoparietal fascia Sentinel v. Zygomaticotemporal n. Superficial layer of temporal fascia Temporoparietal fascia (reflected) Superior auricular a. Transparent superficial fat pad

Superficial temporal a.

Zygomatic arch Superficial temporal v.

Auriculotemporal n.

Zygomatic br. Facial n.

Transverse facial a. Retromandibular v. Zygomaticus major m. Transverse facial a. Masseter m. External carotid a. Zygomaticobuccal br. Buccal branch Parotid duct

Fig. 6.3. The temporal region. The temporoparietal fascia and subgaleal fat pad have been refl ected anteriorly.

The “sentinel vein” is the signal for the proximity of the tem- margin of the orbit. This nerve is located about 1 cm lateral poral branch of the facial nerve. The temporal branch of the to the sentinel vein that passed between a perforation in facial nerve, which courses along the undersurface of the tem- the temporal fascia and the skin surface. The temporal branch poroparietal fascia, is generally found cephalad to the sentinel of the facial nerve has a communication with the zygomati- vein. This vein is located approximately 5 mm lateral to the cotemporal nerve at the temporal region. The zygomatico- frontozygomatic suture line and is a tributary of the internal temporal nerve gives a branch to the lacrimal nerve in maxillary vein draining the temporal region. the orbit, and parasympathetic fi bers that are associated with The zygomaticotemporal nerve provides sensation to the the pterygopalatine ganglion are conveyed to the lacrimal temporal skin. This nerve emerges from the orbit into gland. the temporal fossa at approximately 14 mm inferior to the The superfi cial fat pad is the interfascial fat pad between frontozygomatic suture and 10 mm lateral to the lateral the superfi cial and deep layer of the temporal fascia.

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Superficial layer of Superficial fat pad temporal fascia (Interfascial fat pad)

Sentinel v. Deep layer of temporal fascia

Zygomaticotemporal n.

Middle temporal v. Transparent deep fat pad Temporoparietal fascia Temporoparietal fascia (reflected downward) (reflected) Superficial temporal a., v. Zygomatic arch

Retromandibular v.

Facial n. Transverse facial a.

Fig. 6.4. The temporal region. The superfi cial layer of the temporal fascia has been refl ected upward.

The facial nerve branches mostly course on the lateral side of the parotid gland. The retromandibular vein is joined by the the retromandibular vein. There may be some parotid tissue maxillary vein in the parotid gland. Near the tail of the parotid between the nerve and the vein. gland, it usually divides into anterior and posterior branches. The sentinel vein passes backward, inferiorly and deeply, The deep fat pad, which is between the temporalis muscle through the temporal fascia to the middle temporal vein. The and the deep layer of the temporal fascia, is transparent middle temporal vein passes deeply on the temporalis muscle through the deep layer of the temporal fascia. The temporal and comes up to be joined by the superfi cial temporal vein fascia splits into the superfi cial and the deep layer below the below the zygomatic arch to form the retromandibular vein in level of the superior orbital rim.

c06.indd 35 2/10/2015 1:39:57 PM 36 II Upper Facial and Midfacial Region

Temporalis m.

Middle temporal v. Zygomaticotemporal n. Middle temporal a.

Superficial temporal a., v.

Zygomatic arch

Retromandibular v.

Facial n.

Fig. 6.5. The temporal region. The deep layer of the temporal fascia and the deep fat pad have been removed.

The middle temporal artery arises from the superfi cial tem- The temporal fascia is attached above to the superior tem- poral artery at the level of the zygomatic arch or 1 or 2 cm poral line on the cranium. The superfi cial layer of the tempo- below it. This artery supplies the temporal fascia and approxi- ral fascia is attached onto the lateral border of the zygomatic mately 20% of the posterior and upper parts of the temporalis arch, while the deep layer of the temporal fascia is attached muscle. This artery may leave a groove on the temporal bone onto the medial border of the arch and merges with connec- (see Fig. 2.3 ). tive tissue beneath the masseter muscle. The middle temporal vein arises at approximately the same level as the middle temporal artery and accompanied it closely into the deep fascia.

c06.indd 36 2/10/2015 1:39:58 PM 6 Temporal Region 37

Temporoparietal fascia (galea) and subgaleal fat pad Sentinel v. Superficial layer of temporal fascia Superficial fat pad Upper rim of orbit (Interfascial fat pad) Middle temporal v. Deep layer of temporal fascia

Temporalis m.

Vertex side

Fig. 6.6. The temporal region. The superfi cial and deep layers of the temporal fascia have been separated.

The temporal branch of the facial nerve courses on the The temporal fascia is the fascia of the temporalis muscle. underside of the temporoparietal fascia and into the subgaleal The thick layer arises from the superior temporal line, where fat pad. Several techniques in frontotemporal craniotomy it fuses with the pericranium. The temporalis muscle arises preserve the temporal branch of the facial nerve. The dissec- from the deep surface of the temporal fascia and the entire tion between the deep layer of the temporal fascia and temporal fossa. At the level of the upper orbital rim, the tem- the temporalis muscle is the most reliable technique for poral fascia splits into the superfi cial layer and the deep layer. facial nerve preservation. However, postoperative temporal The former attaches to the lateral border and the latter to the hollowing after the coronal approach is related to a medial border of the zygomatic arch. The fat pad between the decrease in the volume of the superfi cial temporal fat pad. superfi cial and deep layer of the fascia is superfi cial fat pad Therefore, the better cosmetic result can be achieved by (interfascial fat pad). suprafascial (superfi cial layer of the temporal fascia) There are three fat pads in the temporal region: subgaleal, dissection. superfi cial (interfascial), and deep.

c06.indd 37 2/10/2015 1:39:58 PM Superfi cial Structures in the 7 Midfacial Region

Zygomaticofacial n. Temporal brs.

Inferior palpebral branch of infraorbital n. Transverse facial a. Zygomaticobuccal br. of facial n. Zygomatic br.

Zygomatic br. to zygomaticus major m.

Fig. 7.1. The midfacial region. The lower lateral portion of the orbicularis oculi muscle has been refl ected.

Innervation to the lower orbicularis oculi muscle and zygo- The zygomaticofacial nerve (shown in Fig. 7.1 with blue maticus major muscle are shown. The zygomaticus major sheet under it) is a sensory nerve, which supplies the small muscle is innervated by the zygomatic branches and also region of the cheek, and it is divided from the zygomatic from the zygomaticobuccal branches (see Fig. 7.5 ) in its lower nerve in the orbit. part of the muscle. The lower orbicularis muscle is innervated The transverse facial artery, which originates from the from its inferolateral side by one or two zygomatic branches superfi cial temporal artery within the parotid gland, courses and temporal branches. anteriorly beneath the masseteric fascia above the parotid duct.

c07.indd 38 2/10/2015 1:40:02 PM 7 Superfi cial Structures in the Midfacial Region 39

Temporal brs. Orbicularis oculi m.

Lateral nasal a. Zygomatic brs. Levator labii superioris m. Transverse facial a. Buccal br. Infraorbital n. Parotid duct Zygomaticobuccal brs. Levator anguli oris m. Parotid gland Zygomaticus major m. Masseteric fascia

Buccinator m. Great auricular n. Premasseteric a.

Orbicularis oris m. Marginal mandibular br. Depressor anguli oris m. External jugular v. Cervical br. Facial a., v.

Platysma m. Sternocleidomastoid m.

Fig. 7.2. The midfacial region.

The buccinator muscle, upper orbicularis oris muscle, and branches can also be exposed via preauricular skin incision. levator anguli oris muscle are innervated by the zygomatico- The careful selection of the donor facial nerve branches is buccal branches (see Fig. 7.5 ). The buccinator muscle and the mandatory for facial reanimation surgery because some of levator anguli oris muscle are the deep-seated muscles and the buccal and zygomaticobuccal branches might not inner- they are innervated from their superfi cial surface. vate the zygomaticus major muscle, which is the target The anterior margin of the parotid gland is a site which is muscle for smile reconstruction. suitable to identify the zygomatic and buccal branches for The levator anguli oris muscle arises from the canine fossa facial reanimation surgery. Several zygomatic and buccal of the maxilla, immediately below the infraorbital foramen, branches can be exposed via the small skin incision made just and passes downward toward the corner of the mouth. It below the zygomatic arch and anterior to the mandibular elevates the corner of the mouth. notch. The notch can be identifi ed by palpation. These

c07.indd 39 2/10/2015 1:40:02 PM 40 II Upper Facial and Midfacial Region

Auriculotemporal n.

Zygomatico-orbital a.

Superficial temporal a., v. Orbicularis oculi m. Temporal brs.

Zygomatic brs.

Levator labii superioris m. Transverse facial a. Facial v. Buccal br. Infraorbital n. Parotid duct Facial a. Zygomaticus major m. Parotid gland

Levator anguli oris m. Masseteric fascia

Fig. 7.3. The midfacial region. Close-up view of upper branches of the facial nerve.

The facial nerve branches do not always run on the same The buccal branch of the facial nerve has a close relation- plane. Some of the zygomatic branches run beneath the mas- ship with the parotid duct. The branch is most likely inferior seteric fascia anterior to the parotid gland. It is also an impor- and within 1 cm to the duct. tant surgical point that we can only divide the parotid gland just over the facial nerve branch during the dissection of the facial nerve branches in the parotid gland.

c07.indd 40 2/10/2015 1:40:03 PM 7 Superfi cial Structures in the Midfacial Region 41

Orbicularis oculi m. Temporal brs. of facial n. Masseteric fascia Inferior palpebral br. Transverse facial a. of Infraorbital n. Zygomatic brs. Levator labii superioris m. of facial n. and zygomaticus minor m. Parotid gland (reflected medially) Parotid duct Infraorbital n., a. Communicating br. Buccal brs. of facial n. Lateral nasal a. Levator anguli oris m.

Zygomaticus major m. Masseteric fascia Orbicularis oris m. Facial v. Buccinator m.

Fig. 7.4. The midfacial region. Deep seated mimetic muscles and the infraorbital nerve are shown.

Some of the zygomaticobuccal branches (see Fig. 7.5 ) course The levator anguli oris and buccinator muscles are in downward along the parotid duct, pass under the zygomatic the deepest layer of the mimetic muscles and are innervated major muscle, then course upward to reach the lower orbicu- from their superfi cial surface. The levator anguli oris muscle, laris oculi muscle, and fi nally end up at the medial canthal which originated from the canine fossa, inserts into the region. The upper orbicularis oris muscle is generally inner- modiolus. vated by the zygomaticobuccal branches. The branches reach The facial nerve branches have communications with the its upper lateral side, which is medial to the zygomaticus branches of the infraorbital nerve. major muscle.

c07.indd 41 2/10/2015 1:40:03 PM 42 II Upper Facial and Midfacial Region

Orbicularis oculi m. Superficial temporal a., v.

Temporal brs. Inferior palpebral br. Zygomatic br. Retromandibular v. Transverse facial a. Levator labii superioris m. and zygomaticus minor m. Parotid duct Temporofacial division

Levator anguli oris m. Cervicofacial division Zygomaticus major m. Buccal brs.

Buccinator m. Masseter m. without the fascia

Fig. 7.5. The midfacial region. Zygomaticobuccal plexus is shown. The superfi cial lobe of the parotid gland has been removed.

The facial nerve divides into temporofacial (upper trunk) and procerus, nasalis, depressor septi, levator anguli oris, and cervicofacial (lower trunk) divisions just before entering the levator labii superioris) are generally innervated by the zygo- parotid gland. These divisions generally pass forward over the maticobuccal branches. retromandibular vein in the parotid gland. The zygomaticus major muscle originates from the lateral The facial nerve and its branches course in the parotid surface of the zygomatic bone, just in front of the zygomati- gland, thereby dividing the parotid gland into deep and super- cotemporal suture. It pulls the corner of the mouth upward fi cial lobes. There is no anatomical plane between the lobes. and outward. The inferior zygomatic branches usually form a zygomati- The zygomaticus minor muscle originates from the zygo- cobuccal plexus (see circled area ) with the buccal branches. matic bone just in front of the origin of zygomaticus major The mimetic muscles (zygomaticus major, zygomaticus and runs downward and forward to insert into the upper lip. minor, risorius, lower orbicularis oculi, corrugator supercilii, It elevates the upper lip.

c07.indd 42 2/10/2015 1:40:04 PM 7 Superfi cial Structures in the Midfacial Region 43

Superficial temporal a., Retromandibular v.

Tragal pointer Great auricular n. Auricular br. of posterior auricular a. Temporofacial division Facial n. Buccal brs. Occipital a. Occipital br. of posterior auricular a. Posterior auricular a. Cervicofacial division

Marginal mandibular br. Posterior auricular v. Posterior belly Marginal mandibular br., of digastric m. Cervical br. Retromandibular v.

Fig. 7.6. The midfacial region. The intraparotid facial nerve branches are shown.

The buccal branches generally originate from both the upper facial nerve on exiting the stylomastoid foramen. The facial and lower trunk of the facial nerve and connect with the nerve exits about 1 cm below and medial to the tip of the marginal mandibular branch. tragal pointer. However, the cartilage is mobile and asym- The tragal pointer or cartilage, which lies anterior to the metrical, with a blunt irregular tip, so it might be diffi cult to opening of the external acoustic meatus, points directly to the decide on the position of the tragal pointer.

c07.indd 43 2/10/2015 1:40:05 PM 44 II Upper Facial and Midfacial Region

Superficial temporal a.

Auriculotemporal n., Communicating brs. Zygomatic brs. Transverse facial a.

Zygomaticus major m.

Retromandibular v. Zygomaticobuccal brs. Facial n.

Condylar process Buccal brs.

Parotid gland Masseter m.

Fig. 7.7. The midfacial region. The substance of the parotid gland has been removed.

The facial nerve communicates with the trigeminal nerve. meatus. Study shows that the branches of the auriculotempo- The auriculotemporal nerve courses from the posterome- ral nerve constantly communicate with the upper trunk of the dial aspect of the neck of the mandibular condyle to an antero- facial nerve in the parotid gland. These communications might lateral direction to wrap around the neck of the condyle. It convey proprioceptive impulses from the upper facial muscles emerges approximately 1.5 cm below the condylar head. This to the trigeminal nuclei of the brainstem. nerve innervates the capsule of the temporomandibular joint. The retromandibular vein in the parotid gland is a land- On entering the parotid gland, it turns to emerge superfi cially mark for the facial nerve branches. The vein mostly courses between the temporomandibular joint and external acoustic just beneath the facial nerve.

c07.indd 44 2/10/2015 1:40:05 PM 7 Superfi cial Structures in the Midfacial Region 45

Supratrochlear v. Corrugator supercilii m. Orbital septum Supraorbital v. Procerus m. Superior palpebral a. Angular v. Medial palpebral ligament External nasal v. Orbicularis oculi m. Inferior palpebral a. Levator labii superioris Alar arcade from alaeque nasi m. lateral nasal a. Alar cartilage

Lateral nasal a. Levator labii superioris m. Levator labii superioris m.

Infraorbital n., a., v. Facial V. Levator anguli oris m. Septal a. Columellar a. Septal a.

Fig. 7.8. The midfacial region. The mimetic muscles have been removed to leave their attachments.

The angular vein is formed by the confl uence of the supraor- the mandible. The angular vein also has valves in its tributar- bital and supratrochlear veins at the medial eyelid area. ies. There is a communication between the facial vein The transverse supraorbital vein, which joins the supratroch- and cavernous sinus via the supratrochlear and superior oph- lear veins on the medial side and the superfi cial temporal thalmic veins. The infraorbital vein links the facial vein with vein on the lateral side, is located in the supraorbital area (see the pterygoid venous plexus in the infratemporal fossa (see Fig. 5.3 ). The angular vein becomes the facial vein at its junc- Fig. 10.4 ). tion with the superior labial vein, but the latter is not invari- The septal artery and columellar artery, which supplies the ably present. The external nasal vein drains the external nose nasal septum and columella, generally originate from and empties into the angular or facial vein. The facial vein the superior labial artery. Bilateral lateral nasal arteries form does have venous valves, particularly around the level of the alar arcade on the dorsum of nose.

c07.indd 45 2/10/2015 1:40:06 PM 46 II Upper Facial and Midfacial Region

Zygomaticobuccal brs. to procerus and corrugator supercilii m. Dorsal nasal a. Orbicularis oculi m.

Facial v. Nasalis m. (transverse part)

External nasal br. Levator labii superioris m. (Infraorbital n.) Zygomaticus minor m. Zygomaticobuccal br. Zygomaticus major m. to nasalis m. Infraorbital n., a. Lateral nasal a.

Superior labial br. (Infraorbital n.)

Levator anguli oris m. Zygomaticobuccal br. of facial n. Septal a., Columellar a. Zygomaticus major m. Superior labial a. Facial v.

Fig. 7.9. The midfacial region. The proximal site of the zygomaticobuccal branches are cut and dislocated downward.

Innervation to the procerus, corrugator supercilii and nasalis The facial artery bifurcates into the lateral nasal artery and muscles are shown. These muscles are dominantly innervated superior labial artery at the angle of the mouth. After the by the zygomaticobuccal branches (see Fig. 7.5 ), although the bifurcating, the facial artery terminates as the angular artery, corrugator supercilii muscle might be innervated by the tem- which communicates with the dorsal nasal artery of the oph- poral branches of the facial nerve. thalmic artery. The communications between the infraorbital nerve and zygomaticobuccal branches are shown.

c07.indd 46 2/10/2015 1:40:07 PM 7 Superfi cial Structures in the Midfacial Region 47

Levator labii superioris alaeque nasi m. Orbicularis oculi m.

Nasalis m. (transverse part) Levator labii superioris m.

Infraorbital n., a.

Lateral nasal a. Facial v.

Levator anguli oris m. Nasalis m. (alar part)

Periosteum of the Maxilla

Septal a.

Depressor septi m. Facial a. (cut)

Columellar a. Gingiva

Fig. 7.10. The midfacial region. The levator labii muscles have been removed to leave their attachments.

The nasalis muscle arises from the maxilla, overlying the root The levator labii superioris muscle arises from the maxilla of the canine tooth (transverse part) and the lateral incisor at the infraorbital rim, above the infraorbital foramen. (alar part). The transverse part of nasalis inserts into the The levator anguli oris muscle arises from the canine lateral nasal cartilage and also passes over the dorsum of the fossa of the maxilla, immediately below the infraorbital nose to join the opposite side. The alar part of nasalis inserts foramen. into the greater nasal cartilage. The former compresses the The infraorbital nerve emerges from the infraorbital nasal aperture and the latter dilate the nostril. Nasal obstruc- foramen just below the origin of levator labii superioris tion in facial nerve paralysis is due to the nasalis muscle muscle, and it divides into four branches: inferior palpebral weakness. branch, which innervates the lower eyelid skin and conjunc- The depressor septi muscle arises from the incisor region tiva; the external nasal branch, which innervates the lateral of the maxilla and passes upward from beneath the orbicu- surface of nose; the internal nasal branch, which innervates laris oris muscle to insert into the nasal septum. It pulls the the nasal vestibule and nasal septum; and the superior labial nasal septum downward and constricts the nostril. branch, which innervates the upper lip skin and mucosa.

c07.indd 47 2/10/2015 1:40:07 PM 48 II Upper Facial and Midfacial Region

External nasal n.

Lateral nasal wall

b

Levator labii superioris alaeque nasi m. Orbicularis oculi m.

External nasal n. Upper lateral cartilage Infraorbital n., a. Communication between external nasal a. External nasal v. and lateral nasal a. Levator anguli oris m. Alar cartilage Facial v.

Lateral nasal a.

Columellar a. Septal a. Nasalis m., Depressor septi m. a

Fig. 7.11a,b. (a) The midfacial region. The nasalis and depressor septi muscles have been removed to leave their attachments, (b) Medial view of the lateral nasal wall.

The anterior ethmoidal nerve and artery enter the roof of the between the nasal bone and the lateral nasal cartilage. When nasal cavity and give rise to the lateral and medial internal the anterior ethmoidal nerve and artery emerge at the infe- nasal branches. The lateral internal branches pass to the rior margin of the nasal bone, they become the external nasal lateral wall of the nose, whereas the medial internal nasal nerve and artery. The external nasal nerve and artery supply branches run to the nasal septum. These branches supply an the nasal tip, with the exception of the nasal alar region. area in front of the nasal conchae and the anterior extremities The lateral nasal artery or superior labial artery gives off of the middle and inferior conchae. Then, the nerve and artery the septal artery to the nasal septum, and the former com- run under the surface of the nasal bone (Fig. 7.11b ) and pass municates with the external nasal artery.

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Nasal bone Deep temporal n. Zygomaticofacial n. Nasomaxillary suture Zygomaticofacial foramen

External nasal n. Zygomatic bone Infraorbital n., a. Zygomaticomaxillary suture Buccal n. External nasal a. Anterior superior alveolar n., a. Maxillary a.

Nasal septum Lateral pterygoid plate

Maxillary bone Maxillary tuberosity

Fig. 8.1. The maxillary region. The mimetic muscles have been removed.

The infraorbital nerve and zygomaticofacial nerve pass nonexistent, so the posterior superior alveolar nerve alone through each foramen respectively. The zygomaticofacial innervates the premolars and molars. nerve supplies the skin over the prominence of the cheek. The infraorbital artery originates from the pterygopalatine The anterior superior alveolar nerve arises from the infra- segment of the maxillary artery. It enters the orbit through orbital nerve within the infraorbital canal and runs within the inferior orbital fi ssure, runs on the fl oor of the orbit in the the bone of the anterior maxillary wall. It supplies the ante- infraorbital groove and canal, and emerges onto the face at rior third of half side of teeth. the infraorbital foramen. The middle superior alveolar nerve is an inconsistent The anterior superior alveolar artery originates from branch that arises from the infraorbital nerve or maxillary the infraorbital artery within the infraorbital canal. It sup- nerve. It supplies the sinus mucosa, the middle third of half plies the anterior teeth and the anterior part of the maxillary side of teeth when it presents. In the majority of cases, it is sinus.

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Orbit Nasolacrimal duct

Infraorbital n., a.

Maxillary ostium

Orbital floor

Nasolacrimal torus

Posterior wall of maxillary sinus Gingiva Masseter m.

Fig. 8.2. The maxillary region. The anterior wall of the maxilla has been removed to expose the sinus and nasolacrimal duct.

The infraorbital nerve and vessels run on the roof of the max- The bony canal for the nasolacrimal duct has been illary sinus. The maxillary ostium is seen at a high position partially opened to expose the nasolacrimal duct. The behind the nasolacrimal duct on the medial wall of the sinus. duct forms a bony torus on the medial wall of the maxillary An accessory ostium is sometimes present behind the major sinus. ostium. The innervation of the maxillary sinus is derived from the maxillary nerve via its infraorbital and anterior, middle, and posterior superior alveolar nerves.

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Orbit Nasolacrimal duct

Maxillary ostium

Nasolacrimal torus Infraorbital n., a.

Ethmoid sinus

Sphenoid sinus

Gingiva Sphenopalatine a. Maxillary n.

Pterygopalatine ganglion

Greater palatine n., a. Masseter m.

Fig. 8.3. The maxillary region. The posterior and medial walls of the maxilla have been opened.

The ethmoid sinus and the sphenoid sinus have been opened accompanies the posterior superior nasal nerve and supplies through the medial maxillary wall. The infraorbital nerve and the posterior part of the lateral nasal wall before crossing vessels are exposed by removing the bony roof of the maxil- the roof of the nasal cavity to accompany the nasopalatine lary sinus. nerve and supply the posterior-inferior part of the nasal The sphenopalatine artery enters the lateral wall of the septum. nose through the sphenopalatine foramen. The artery

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Ethmoidal sinus

Sphenoid sinus Infraorbital n. Zygomatic n.

Foramen rotundum Middle superior alveolar n. V2 Infraorbital a. Ganglionic branches Posterior superior alveolar n. Sphenopalatine a. Pterygopalatine ganglion

Greater & Lesser palatine n.

Posterior superior alveolar a. Maxillary a. Greater & Lesser palatine a. Lateral pterygoid m. Pterygoid plate

Fig. 8.4. The maxillary region. The veins have been removed.

The pterygopalatine ganglion is a parasympathetic ganglion The nasopalatine nerve and sphenopalatine vessels run found in the pterygopalatine fossa and largely innervated by into the nasal cavity through the sphenopalatine foramen, the greater petrosal nerve. It is situated just below the maxil- and they pass across the roof of the nasal cavity to reach the lary nerve. The ganglionic branches, usually two in number, nasal septum and supply the posteroinferior part of the nasal connect the maxillary nerve to the pterygopalatine ganglion. septum. The pterygopalatine ganglion supplies the lacrimal gland, the The zygomatic nerve arises in the pterygopalatine fossa paranasal sinuses, the glands of the mucosa of the nasal from the maxillary nerve. It enters the orbit by the inferior cavity and pharynx, the gingiva, and the mucous membrane orbital fi ssure and divides at the back of that cavity into and glands of the hard palate. two branches, the zygomaticotemporal nerve and the zygo- The pterygopalatine fossa contains blood vessels and maticofacial nerve. The zygomatic nerve carries sensory nerves supplying the nose, palate, and upper jaw, including fi bers from the skin. It also carries postsynaptic parasympa- the maxillary division of the trigeminal nerve which passes thetic fi bers (originating in the pterygopalatine ganglion) to through the foramen rotundum; the nerve of the pterygoid the lacrimal nerve via a communication. These fi bers will canal and accompanying vessels which pass through the pter- eventually provide innervation to the lacrimal gland. These ygoid canal; the nasopalatine and posterior superior nasal parasympathetic postganglionic fi bers come from the facial nerves and the sphenopalatine vessels which pass through nerve. the sphenopalatine foramen; the greater and lesser palatine The third segment of the maxillary artery is the pterygo- nerves, which together with accompanying vessels pass palatine segment. It has fi ve branches: the posterior superior through the greater and lesser palatine foramina. The pharyn- alveolar artery, the infraorbital artery, the artery of the ptery- geal branch of the pterygopalatine ganglion runs through the goid canal, the descending palatine artery, and the spheno- palatovaginal canal to supply the nasopharyngeal mucosa. palatine artery.

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Incisive a., n.

Greater palatine a., n. Lesser palatine a.

Palatine aponeurosis

Pterygoid hamulus

Levator veli palatini m.

Ascending palatine a.

Fig. 8.5. The palatal region. The palatal mucosa has been removed on the right side and the soft palate has been removed on the left side.

The greater and lesser palatine nerves and arteries pass from The lesser palatine nerve and artery emerge onto the palate the pterygopalatine fossa down the greater palatine canal at the lesser palatine foramen. They run backward into the at the back of the lateral wall of the nose. The greater palatine soft palate. nerve and artery run through the greater palatine foramen The nasopalatine nerve terminates as the incisive nerve and onto the back of the hard palate. They pass toward which passes through the incisive canal with an accompany the front of the hard palate. They supply the palatal mucosa artery onto the hard palate to supply oral mucosa around the and palatal gingiva. Within the greater palatine canal, the incisive papilla. It communicates with the corresponding nerve and artery give off nasal branches that innervate nerve of the opposite side and with the greater palatine the posteroinferior part of the lateral wall of the nasal cavity. nerve.

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Hard palate

Deep temporal n., Masseteric n. Greater palatine a., n.

Lesser palatine a. Pterygoid hamulus Posterior edge of nasal septum Tensor veli palatini m. Palatine aponeurosis Maxillary a.

Levator veli palatini m. Ascending palatine a.

Inferior alveolar n.

Soft palate Buccinator m. Lingual n.

Fig. 8.6. The palatal region. The levator and tensor veli palatini muscles are shown on the left side.

The tensor veli palatini muscle arises from the scaphoid Eustachian tube. The muscle curves downward, medially, and fossa of the sphenoid bone (at the root of the pterygoid plate) forward to enter the palate immediately below the opening and from the lateral side of the cartilaginous part of the of the Eustachian tube. This muscle produces upward and Eustachian tube. The fi bers converge toward the pterygoid backward movement of the soft palate. This muscle is inner- hamulus, where the muscle becomes tendinous. The tendon vated by the accessory nerve via the pharyngeal plexus. bends at right angles around the hamulus to become the The ascending palatine artery originates from the facial palatine aponeurosis. The aponeurosis is attached to the pos- artery in the neck. It divides near the levator veli palatini terior border of the hard palate. This muscle pulls the soft muscle into two branches. One supplies and follows the palate laterally. This muscle is innervated by the branch of the course of this muscle and, winding over the upper border of mandibular nerve via the nerve to the medial pterygoid the superior pharyngeal constrictor, supplies the soft palate muscle. and the palatine glands. The other pierces the superior pha- The levator veli palatini muscle originates from the base of ryngeal constrictor and supplies the palatine tonsil and audi- the skull at the apex of the petrous part of the temporal bone tory tube, anastomosing with the tonsillar branch of the facial and from the medial side of the cartilaginous part of the artery and the ascending pharyngeal artery.

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Zygomaticotemporal n. Middle temporal a. Middle temporal v.

Temporalis m. Superficial temporal a. Middle temporal a. Zygomatic arch Superficial temporal v. Auriculotemporal n. Orbicularis oculi m. Lateral ligament (reflected) Zygomaticus major m. Retromandibular v.

Auriculotemporal n. Muscle br. Facial n. Masseter m. Transverse facial a. Mandibular condyle Parotid duct

Fig. 9.1. The masseteric region. The parotid gland and the facial nerve branches have been removed.

The zygomaticus major muscle, the masseter muscle, and the the posterior auricular vein to form the external jugular vein. temporal fascia and lateral ligament are the structures which The common facial vein drains into the internal jugular vein are attached to the zygomatic arch. (see Fig. 11.2 and Fig. 12.3 ). The origin of the zygomaticus major muscle is the subzygo- The temporomandibular joint has one major ligament, the matic fossa, which is located posterior and inferior to the malar temporomandibular ligament, also termed the lateral liga- eminence and anterior to the zygomaticotemporal suture. The ment, which is actually the thickened lateral portion of the subzygomatic fossa is usually an easily palpable landmark. capsule. It has two parts: an outer oblique portion and an The retromandibular vein usually divides into anterior and inner horizontal portion. The base of this triangular ligament posterior branches near the tail of the parotid gland. Outside is attached to the zygomatic process of the temporal bone and the gland, anterior branch joins the facial vein to form the the articular tubercle. Its apex is fi xed to the lateral side of common facial vein, while the posterior branch unites with the neck of the mandible.

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Zygomatic arch

Zygomaticus major m. Lateral ligament

Attachment of superficial part of masseter m. Middle part of masseter m.

Masseteric n., a., v. Buccal fat pad

Parotid duct Masseter m. (cut and reflected) (superficial part)

Buccinator m.

Fig. 9.2. The masseteric region. The superfi cial part of the masseter muscle has been refl ected.

The masseter muscle is one of the muscles of mastication. It force. The lateral pterygoid muscle assists in opening the is quadrilateral in shape and consists of three layers. The mouth, but its main action is to draw forward the condyle layers are fused anteriorly, but diverge posteriorly. The most and articular disk so that the mandible is protruded and pronounced layer is superfi cial. It originates from the anterior the inferior incisors projected in front of the upper. In this two-thirds of the inferior border of the zygomatic arch up to action, it is assisted by the medial pterygoid muscle. The the zygomatic process of the maxilla. Initially, it is aponeu- mandible is retracted by the posterior fi bers of the temporalis rotic and passes obliquely in an inferomedial direction. It muscle. The medial and lateral pterygoid muscle of two sides inserts into the inferior border of the external surface of the contract alternately to produce side-to-side movement of the angle of the mandible. Its insertion extends anteriorly to the mandible. junction of the ramus with the body of the mandible. The transfer of functional innervated musculature into the The chief muscles of mastication are the temporalis, mas- face off ers the possibility of meaningful facial movement. And seter, medial pterygoid, and lateral pterygoid. The fi rst three the temporalis, masseter, and digastric muscles can be used muscles raise the mandible against the maxilla with great for facial reanimation.

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Middle temporal v.

Superficial temporal a., v. Orbicularis oculi m. (reflected) Zygomatic arch Lateral ligament Zygomaticus major m. Attachment of middle part Retromandibular v. Attachment of superficial part Masseteric n., a., v. Deep part of masseter m. Facial n. Buccal fat pad Middle part of masseter m. Parotid duct (cut and reflected)

Fig. 9.3. The masseteric region. The middle part of the masseter muscle has been refl ected.

The masseteric nerve and vessels course anteroinferiorly on deep parts of masseter muscle permits the entry of its blood the deep part of the masseter muscle after passing the man- supply—the masseteric artery—which is a branch of the max- dibular notch. illary artery. The deep part of masseter muscle has a similar The middle part of masseter muscle originates from the course to the middle part but is separated from it by the mas- middle third of the zygomatic arch. It blends with the super- seteric nerve. Similar to the artery, the nerve enters posteri- fi cial part at the mandibular insertion and anteriorly. The orly where the layers diverge. posterior divergence of fi bers between the superfi cial and

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Middle temporal v. Superficial temporal a.

Temporalis m. Superficial temporal v.

Zygomatic arch Auriculotemporal n. Lateral ligament Retromandibular v.

Zygomaticus major m. Mandibular condyle Facial n. Coronoid process Masseteric n. Tendon of temporalis m. Mandibular notch External carotid artery Buccal fat pad Masseter m. (middle, deep part)

Masseter m. Facial v. (superficial part) Parotid duct (reflected)

Fig. 9.4. The masseteric region. The every part of the masseter muscle has been refl ected downward.

The upper border of the ramus of mandible is thin and is landmarks can be used to identify the masseteric nerve. The surmounted by two processes, the coronoid process anteri- mandibular notch is a palpable and reliable bony landmark orly and the condylar process posteriorly. These are separated for identifying the masseteric nerve, which is located just by a deep concavity, the mandibular notch, or sigmoid notch. above the notch on the deep part of the masseter muscle. The It allows the passage of the masseteric nerve, the masseteric masseteric nerve is a potential source of axons for facial rein- artery, and the masseteric vein. nervation when the proximal facial nerve stump is not avail- The masseteric nerve leaves the infratemporal fossa able but the distal facial nerve and facial musculature are through the mandibular notch. At this level, the nerve usually present and functional. consists of one or more branches. Several intraoperative

c09.indd 58 2/10/2015 1:40:19 PM 9 Masseteric Region 59

Middle temporal v.

Temporal extension of buccal fat pad Superficial temporal v. (Deep temporal fat pad) Superficial temporal a. Auriculotemporal n.

Facial n. Tendon of temporalis m. Masseteric n.

Buccal extension of buccal fat pad Ramus Retromandibular v.

Fig. 9.5. The masseteric region. The zygomatic arch has been removed and the deep temporal fat pad preserved.

The buccal fat pad is located superfi cial to the buccinator capsule. The proposed function is to provide a surface for the muscle at the anterior edge of the masseter muscle and pro- gliding motion of the muscles of mastication. The temporal vides fullness to the cheek inferior to the malar prominence. extension of the buccal fat pad is identical to the deep tem- It has three main extensions: buccal, pterygoid, and temporal. poral fat pad, which is situated between the temporalis These extensions are each contained within a separate muscle and the deep layer of the temporal fascia.

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Middle temporal v. Zygomaticotemporal n. Superficial temporal a. Middle temporal a. Superficial temporal v.

Temporalis m. Lateral ligament, Joint capsule

Masseteric n. Facial n.

Occipital a. External carotid a. Buccal fat pad Ramus Retromandibular v. Posterior belly of Parotid duct digastric m. Stylohyoid m. Buccinator m. Masseter m.

Fig. 9.6. The masseteric region. The deep temporal fat pad has been removed.

The temporalis muscle arises from the fl oor of the temporal commissure and provides trigeminally controlled dynamic fossa and from the overlying temporal fascia. The fi bers con- movement. verge toward their insertion onto the apex, the anterior and The middle temporal artery, which is a branch of the posterior borders, and the medial surface of the coronoid superfi cial temporal artery, arises immediately above the process, and the anterior border of the ramus almost as far as zygomatic arch, and, perforating the temporal fascia, gives the third molar tooth. Many of the fi bers have a tendinous branches to the temporalis muscle, anastomosing with the insertion. The anterior (vertical) fi bers of the temporalis deep temporal artery. It supplies the posterior part and the muscle elevate the mandible; the posterior (horizontal) fi bers upper part of the temporalis muscle. retract it. The temporalis muscle is an alternative muscle for reani- mation of the smile. It serves as a static support to the oral

c09.indd 60 2/10/2015 1:40:20 PM 10 Deep Structures in the Midfacial Region

Semicircular canal Geniculate ganglion V2 (GSPN cut) Internal carotid a. V3 Incus Tensor tympani m.

Zygomaticotemporal n.

Frontozygomatic suture Zygomaticotemporal foramen Middle temporal a.

Deep temporal n., a., v. Superficial temporal a., v. Auriculotemporal n. Root of zygomatic arch

Temporalis m. (reflected) Zygomaticofacial n.

Fig. 10.1. Superior view of the middle fossa and temporal fossa.

The neurovascular bundle is shown on the deep surface of the zygomaticotemporal nerve emerges from the orbit into the temporalis muscle. The dissection of the muscle from the temporal fossa at approximately 14 mm inferior to the fron- temporal bone might cause the muscle to atrophy because of tozygomatic suture and 10 mm lateral to the lateral margin of damage to its motor nerves. the orbit through the zygomaticotemporal foramen. Then, it The zygomaticotemporal nerve is a terminal branch of passes through the temporalis muscle and pierces the tempo- the maxillary division of the trigeminal nerve. The zygo- ral fascia about 2 cm above the zygomatic arch. The foramen matic nerve enters the orbit through the inferior orbital is always found posterolateral to the edge of the lateral orbital fi ssure, and it divides into the zygomaticotemporal and rim. It is a sensory nerve that provides sensation to the skin zygomaticofacial nerves along the lateral wall of the orbit. The of the temporal region.

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Buccal n., Anterior Mandibular n., deep temporal nerve Foramen ovale Middle meningeal a.

Br. to upper head of Lateral pterygoid m. Upper head of lateral pterygoid m.

Middle and Posterior deep temporal n.

Anterior deep temporal a. Masseteric n. Posterior deep temporal a.

Temporalis m.

Masseter m. (deep part) Zygomatic arch

Fig. 10.2. Superior view of the middle fossa without bone.

The buccal nerve and the anterior deep temporal nerve gen- Three main arteries supply the temporalis muscle: the erally pass between the upper and lower heads of the lateral anterior deep temporal, the posterior deep temporal, and the pterygoid muscle. The middle and posterior deep temporal middle temporal. The anterior deep temporal artery, which nerve and masseteric nerve run on the superior surface of the arises from the pterygoid segment of the internal maxillary upper head. artery, enters the anterior portion of the muscle and supplies The temporalis muscle is innervated predominantly by the about 30% of the muscle. The posterior deep temporal artery, deep temporal nerves, which are branches of the anterior which arises from the same segment of the maxillary artery, trunk of the mandibular nerve. The number of the deep tem- enters the central part of the muscle and supplies about 50% poral nerves generally vary from one to fi ve. The temporal of the muscle. The middle temporal artery. which arises from branches, which innervate the temporalis muscle, also arise the superfi cial temporal artery, supplies the temporal fascia from the buccal nerve and the masseteric nerve. They inner- and approximately 20% of the posterior and upper parts of vate the anterior and posterior part of the temporalis muscle the temporalis muscle. respectively.

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Deep temporal n. Masseteric n. (reflected) Superior, inferior joint space Zygomaticofacial n. Articular disc Superficial temporal a. Lateral pterygoid m. Mandibular condyle (upper head) Auriculotemporal n. Infraorbital a. Maxillary a. Facial n. Buccal n. Deep temporal a. Posterior superior alveolar n., a., v. Lateral pterygoid m. External carotid a. (lower head) Medial pterygoid m. Deep facial v. (superficial head) Buccal a., lingual br. Buccinator m. Inferior alveolar n., a. Minor salivary gland Lingual n. Facial v. Mandible Parotid duct (partially removed)

Fig. 10.3. Infratemporal fossa. The temporalis muscle and the coronoid process have been removed to show the infratemporal fossa.

The lingual nerve is a branch of the posterior trunk of middle meningeal artery, an accessory meningeal artery, and the mandibular nerve. It is essentially a sensory nerve. It the inferior alveolar artery. emerges from the inferior border of the lateral pterygoid The inferior alveolar artery and vein descend downward muscle and curves downward and forward in the space and forward to join the inferior alveolar nerve. They descend between the ramus of the mandible and the medial pterygoid to the mandibular foramen on the medial surface of the muscle. ramus of the mandible and run along the mandibular canal The maxillary artery is a terminal branch of the external in the substance of the bone. Opposite the fi rst premolar carotid artery. It arises at the posterior border of the man- tooth, they divide into two branches: incisor and mental. dibular neck. It is divided into three segments. The fi rst is the The temporomandibular joint (TMJ) is formed by the mandibular segment, which lies behind the mandible and condyle of the mandible articulating in the mandibular fossa courses horizontally between the neck of the mandible and (glenoid fossa) of the temporal bone. The joint cavity is lateral to the sphenomandibular ligament. This segment has divided into two by an intra-articular disc. Its margins merge fi ve branches and all enter bone, where the segment lies par- with the joint capsule. The TMJ is basically a hinge joint, but allel to and a little below the auriculotemporal nerve. It it also allows for some gliding movements. Sensory innerva- crosses the inferior alveolar nerve and runs along the lower tion of the temporomandibular joint is derived from the border of the lateral pterygoid muscle. These branches include auriculotemporal nerve and the articular branch from the the deep auricular artery, the anterior tympanic artery, the masseteric nerve.

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Masseteric n. (reflected)

Deep temporal n.

Zygomaticofacial n. Deep temporal a. Inferior orbital fissure Lateral pterygoid m. (upper head) Infraorbital a., n. Lateral pterygoid m. (lower head) Maxillary v. Buccal n.

Maxillary a.

Posterior superior alveolar n., a., v. Deep facial v.

Fig. 10.4. Infratemporal fossa. The probe is passing through the inferior orbital fi ssure.

The lateral pterygoid muscle runs in the horizontal plane artery is passing into the pterygopalatine fossa. It runs onto and occupies most of the infratemporal fossa. It has two the maxillary tuberosity and supplies the maxillary molar distinct heads: a smaller upper infratemporal head and a and premolar teeth through the alveolar canal (see Fig. lower pterygoid one. The infratemporal head originates at 10.13b ), the buccal gingiva, and the maxillary air sinus. The the lateral surface of the greater sphenoid wing and the posterior superior alveolar vein drains into the pterygoid infratemporal crest of the sphenoid bone. It runs parallel to venous plexus or the maxillary vein. the fl oor of the middle cranial fossa and merges posteriorly The inferior orbital fi ssure transmits the maxillary nerve with the pterygoid head. The pterygoid head originates from and its zygomatic branch, the infraorbital vessels, the ascend- the lateral surface of the lateral pterygoid plate and runs ing branches from the pterygopalatine ganglion, and a vein laterally and superiorly. Both heads were inserted in a depres- that connects the inferior ophthalmic vein with the pterygoid sion at the anterior aspect of the neck of the mandible. The venous plexus. The orbitalis muscle (Müller ’ s muscle) occu- muscle assists in opening the jaws by pulling forward the pies the lateral part of the inferior orbital fi ssure and forms a mandibular condyle and the articular disc of the temporo- lamina of smooth muscle fi bers that cover the inferior orbital mandibular joint. The muscle is innervated by the mandibu- fi ssure. The orbitalis muscle is a rudimentary smooth muscle lar nerve. that crosses from the infraorbital groove and sphenomaxil- The posterior superior alveolar artery arises from the max- lary fi ssure and is intimately united with the periosteum of illary artery (pterygopalatine segment), frequently in con- the orbit. It lies at the back of the orbit and spans the infra- junction with the infraorbital artery just as the maxillary orbital fi ssure.

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Masseteric n. (reflected upward) Deep temporal n. Superior joint space Deep temporal a. Articular disc Infraorbital a., n. Auriculotemporal n. Superficial temporal a.

Posterior superior alveolar a., n. Maxillary a., v. Pterygoid venous plexus (deep component) Buccal n. Facial n. Deep facial v. Lateral pterygoid plate

Medial pterygoid m. External carotid a. Buccinator m. Buccal a. (attachment) Retromandibular v. Lingual n. Inferior alveolar n.

Fig. 10.5. Infratemporal fossa. The mandibular condyle and lateral pterygoid muscle have been removed.

The medial pterygoid muscle originates in the pterygoid fossa The pterygoid venous plexus has superfi cial and deep from the medial surface of the lateral pterygoid plate. Its components. The latter is more prominent and is located fi bers pass inferiorly to attach to the medial surface of the between the lateral and medial pterygoid muscles, posterior ramus and angle of the mandible. It elevates the mandible. to the lateral pterygoid plate, around the lingual and inferior The pterygoid segment, which is the second segment of alveolar nerves. It communicates with the cavernous sinus, the maxillary artery, is related to the pterygoid head of the the facial vein, the retromandibular vein, the inferior ophthal- lateral pterygoid muscle. It runs between the infratemporal mic vein, and the pharyngeal plexus. The primary drainage of and pterygoid heads of the lateral pterygoid muscle or later- the pterygoid venous plexus is posteriorly through the retro- ally to the pterygoid head of the lateral pterygoid muscle. It mandibular vein via the maxillary vein. The deep facial vein has fi ve branches: the deep temporal arteries (anterior and connects the facial vein with the pterygoid venous plexus in posterior), the pterygoid artery, the masseteric artery, the the infratemporal fossa. buccal artery, and a small lingual branch.

c10.indd 65 2/10/2015 1:40:26 PM 66 II Upper Facial and Midfacial Region

Masseteric n. Deep temporal a., n. Mandibular fossa Infratemporal crest

Infraorbital a., n. Superficial temporal a.

Anterior trunk Sphenomandibular ligament Buccal n. Posterior superior Auriculotemporal n., alveolar a., n. middle meningeal a. Accessory meningeal a. Facial n. Posterior trunk Maxillary a., v.

External carotid a. Styloid process Buccinator m. Buccal a. Inferior alveolar a., v. Medial pterygoid m. Mandible (cut) Lingual n. Inferior alveolar n.

Fig. 10.6. Infratemporal fossa. The pterygoid venous plexus has been removed.

The auriculotemporal nerve originates from the posterior The roof is the infratemporal surface of the greater sphenoid trunk of the mandibular nerve primarily in one or two wing. The medial wall is the lateral pterygoid plate anteriorly branches. The middle meningeal artery is encircled by them and the tensor veli palatine and medial pterygoid muscles in the latter. The two branches then converge to form a single posteriorly. The anterior wall is the posterior surface of the nerve. This nerve is essentially sensory but it also distributes maxilla. The fossa extends posteriorly to the glenoid fossa and autonomic fi bers to the parotid gland. The auriculotemporal the temporomandibular joint. Superiorly and laterally, the nerve crosses medially to the neck of the mandible and fossa blends into the temporal fossa and the belly of the tem- changes its direction upward in the parotid gland between the poralis muscle. The infratemporal crest is a transverse ridge temporomandibular joint and the external acoustic meatus. of the greater sphenoid wing that separates the temporal The infratemporal fossa is the anatomic space under the fossa from the infratemporal fossa. The inferior boundary of fl oor of the middle cranial fossa and posterior to the maxilla. the fossa is open.

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Deep temporal a. Mastoid tip Facial n.

Deep auricular a. Maxillary a., v.

Sphenomandibular ligament Stylomandibular ligament Occipital a. Accessory n.

Transverse process of atlas Mandible (cut)

Inferior alveolar n. Internal jugular v.

Fig. 10.7. Infratemporal fossa. The accessory ligaments of the temporomandibular ligament.

The accessory ligaments of the temporomandibular ligament spine of the sphenoid bone and descends to the lingula near are the stylomandibular ligament, the sphenomandibular the mandibular foramen in the medial surface of the ramus ligament, and the pterygomandibular raphe (ligament). The of the mandible. The deep auricular artery is the fi rst branch stylomandibular ligament extends from the tip of the styloid from the mandibular segment of the maxillary artery. It process and from the styloid ligament to the angle of the supply the skin of the external acoustic meatus and part of mandible. The sphenomandibular ligament attaches to the the tympanic membrane.

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Deep temporal n., a., Infratemporal crest Masseteric n. Infraorbital a., n. Mandibular fossa Superficial temporal a.

Deep facial v. Auriculotemporal n. Facial v. Middle meningeal a., Lateral pterygoid plate Maxillary a. Facial n. Buccinator m. (attachment) External carotid a. Tensor veli palatini m. Posterior auricular a. Superior pharyngeal constrictor m. Occipital a. Transverse process of atlas Pterygomandibular raphe Stylopharyngeus m. Inferior alveolar n., a., v.

Lingual n. Internal carotid a. Ascending palatine a. Tongue Styloglossus m. Hypoglossal n. Mylohyoid n. Internal jugular v. Facial a.

Fig. 10.8. Infratemporal fossa. The medial pterygoid muscle and the mandible have been removed.

The tensor veli palatini muscle pulls the soft palate laterally. middle portion of the buccinator muscle. It attaches to the When this muscle and the levator veli palatini muscle act pterygoid hamulus superiorly and to the posterior end of the together, the palatine aponeurosis becomes taut and horizon- mylohyoid line of the mandible. tal and provides a platform upon which other palatini muscle The superior pharyngeal constrictor muscle originates may act to change the position of the soft palate (see Fig. 8.6 ). mainly from the posterior border of the pterygomandibular The facial artery gives off the ascending palatine artery, the raphe. This raphe provides the site of origin for both the tonsillar artery, branches to the submandibular gland, and the superior constrictor and buccinator muscles. This muscle submental artery in the neck. constricts the upper part of the pharynx, and it is innervated The pterygomandibular raphe is a ligamentous band from the accessory nerve. between the superior pharyngeal constrictor muscle and the

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Deep temporal a., n., Masseteric n. External acoustic meatus Infraorbital a., n. Superficial temporal a. Chorda tympani n. (petrotympanic fissure) Posterior superior alveolar a., n. (Spine of sphenoid bone has been removed) Auriculotemporal n., Maxillary a. Middle meningeal a. Buccal n. Mastoid tip Facial n. Deep facial v. Stylomastoid a. Br. to digastric m. Lateral pterygoid plate Rectus capitis lateralis m.

Styloid process Posterior auricular a. Tensor veli palatini m. Occipital a. Ascending palatine a. Alveolar process External carotid a. Lingual n. Accessory n. Inferior alveolar n., a. v. Internal jugular v.

Fig. 10.9. Infratemporal fossa. The mandibular fossa has been drilled.

The mandibular nerve is the largest division of the trigeminal three branches: the auriculotemporal nerve, the lingual nerve and has motor and sensory fi bers. The sensory fi bers nerve, and the inferior alveolar nerve. supply the mandibular teeth, the anterior two-thirds of the The lingual nerve is essentially a sensory nerve, but fol- tongue and the fl oor of the mouth, the skin of the lower part of lowing union with the chorda tympani branch of the facial the face, and parts of the temporal and auricular region. The nerve, it also contains parasympathetic fi bers. The nerve lies mandibular nerve lies on the tensor veli palatini muscle after on the tensor veli palatini muscle deep to the lateral pterygoid passing through the foramen ovale. After a short distance, the muscle. Then the chorda tympani nerve, which has entered nerve divides into a smaller anterior trunk and a larger posterior the infratemporal fossa via the petrotympanic fi ssure, joins trunk. Prior to this division, the main trunk gives off the menin- the posterior surface of the lingual nerve. geal branch and the nerve to the medial pterygoid muscle. The tensor veli palatini muscle lies lateral to the Eustachian The anterior trunk has four branches: the masseteric tube. It runs downward toward the pterygoid hamulus at the nerve, the deep temporal nerve, the nerve to the lateral ptery- inferior border of the medial pterygoid plate, and its tendon goid muscle, and the buccal nerve. The posterior trunk has inserts in the soft palate.

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Superficial temporal a. Chorda tympani Maxillary a. Tympanomastoid suture

Facial n.

Mylohyoid n. Levator veli palatini m. Tensor veli palatini m. Posterior auricular a. Occipital a. Inferior alveolar n., a., v. Ascending palatine a. Transverse process of atlas Superior pharyngeal constrictor m. Accessory n. Stylopharyngeus m. Lingual n. Hypoglossal n. Glossopharyngeal n. Internal jugular v. Vagus n.

Fig. 10.10. Infratemporal fossa. The tensor veli palatini muscle has been lifted to show the levator veli palatini muscle.

The levator veli palatini muscle is medial and slightly poste- continues between the superior pharyngeal constrictor rior to the tensor veli palatini muscle. It spreads to attach muscle and the medial pterygoid muscle to near the base of widely to the soft palate. This muscle forms a U-shaped mus- the skull. cular sling. When the palatine aponeurosis is stiff ened by the The stylopharyngeus muscle elevates the pharynx tensor muscles, contraction of the levator muscles produces and larynx, and it is innervated from the glossopharyngeal an upward and backward movement of the soft palate. This nerve. muscle is innervated by the accessory nerve via the pharyn- The styloglossus muscle draws up the sides of the tongue geal plexus. to create a trough for swallowing, and it is innervated by the The ascending palatine artery arises close to the origin of hypoglossal nerve like all muscles of the tongue except the the facial artery and passes up between the styloglossus and palatoglossus muscle, which is innervated by the pharyngeal stylopharyngeus to the side of the pharynx along which it plexus of vagus nerve.

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Deep temporal n., Superficial temporal a. Masseteric n. (reflected) Deep temporal a. Chorda tympani Maxillary a. Auriculotemporal n.

Buccal n. Middle meningeal a.

Lateral pterygoid plate Facial n.

Occipital a.

Levator veli palatini m. Eustachian tube Inferior alveolar n., a., v. (probe is in the tube) Ascending palatine a.

Mylohyoid n. Lingual n. Internal jugular v.

Fig. 10.11. Infratemporal fossa. The tensor veli palatini muscle has been removed.

The mylohyoid nerve, which is given off from the inferior attachment to the tensor veli palatini muscle, the levator veli alveolar nerve just before the mandibular foramen, has motor palatini muscle, and the salpingopharyngeus muscle. The and sensory components. It supplies the mylohyoid muscle tensor veli palatini intervenes between the tube and the man- and the anterior belly of digastric muscle. It also supplies the dibular nerve, the otic ganglion, the chorda tympani nerve, skin of the submental region (see Fig. 11.4 ). and the middle meningeal artery. The functions of the Eusta- The Eustachian tube is also called the auditory tube. It chian tube are pressure equalization and mucus drainage. links the lateral wall of the nasopharynx to the anterior wall Under normal circumstances, the human Eustachian tube is of the tympanic cavity. The Eustachian tube runs anteriorly closed, but it can open to let a small amount of air through to and inferiorly from the middle ear to the nasopharynx. It has prevent damage by equalizing pressure between the middle a bony part in the petrous bone and a cartilaginous part that ear and the atmosphere. The Eustachian tube drains mucus lies in the infratemporal fossa. The cartilaginous part gives from the middle ear.

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Deep temporal a. Deep temporal n. Inferior alveolar n., a. & Masseteric n. (reflected) Infraorbital a., n. Mandibular fossa (opened)

Buccal n. Greater palatine a.

Lingual n. Branch to medial Maxillary a. pterygoid m. Middle meningeal a. Otic ganglion Auriculotemporal n. Vaginal process Eustachian tube (lateral wall of cartilaginous part) Internal carotid a. Levator veli palatini m.

Fig. 10.12. Infratemporal fossa. The mandibular nerve has been lifted to show the otic ganglion.

The otic ganglion is a parasympathetic ganglion, which lies on parasympathetic fi bers originate from the inferior salivatory the medial surface of the main trunk of the mandibular nerve nucleus in the brain stem. The fi bers pass out in the glossopha- immediately below the foramen ovale. It is concerned primar- ryngeal nerve, appearing as the lessor petrosal nerve from the ily with supplying the parotid gland. The parasympathetic, tympanic plexus in the middle ear cavity. Its sympathetic post- sympathetic, and sensory components reach the parotid gland ganglionic fi bers consists of a fi lament from the plexus sur- by way of the auriculotemporal nerve. The preganglionic rounding the middle meningeal artery.

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Alveolar canals

Maxillary tuberosity b Inferior orbital fissure Deep temporal n., (Lateral part) Masseteric n. Infraorbital a., n. Deep temporal a. Posterior superior alveolar n., a.

Greater palatine a.

Anterior trunk pterygomaxillary fissure Posterior trunk Buccal n. Auriculotemporal n.

Lateral pterygoid plate Maxillary tuberosity Maxillary a. Tensor veli palatini m. Lingual n. Br. to medial pterygoid m. Inferior alveolar n. a

Fig. 10.13a,b. Infratemporal fossa. (a) The maxillary artery has been lifted to show the greater palatine artery. (b) Lateral view of the skull with the maxillary tuberosity highlighted.

The posterior superior alveolar nerve arises from the maxil- maxilla and run in the posterior alveolar canals (Fig. 10.13b ) lary nerve in the pterygopalatine fossa. It descends onto the above the roots of the molar teeth. The three superior alveolar posterior wall of the maxilla and divides into dental and gin- nerves (anterior, middle and posterior superior alveolar) form gival branches. The dental branches and vessels enter the a plexus just above the roots of the maxillary teeth.

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Deep temporal a. Infraorbital a. External acoustic meatus

Superficial temporal a.

Pterygoid plate (fractured) Greater palatine a., n. Maxillary a.

Facial n. Maxillary tuberosity

External carotid a.

Eustachian tube Inferior alveolar n., a. Nasopharynx Stylohyoid ligament (cut) (Soft palate has been removed in the Lingual n. left side)

Fig. 10.14. Infratemporal fossa. The pterygoid plate has been fractured.

The pterygopalatine fossa communicates with the emerge at the greater and lesser palatine foramina (see Fig. infratemporal fossa through the pterygomaxillary fi ssure. 8.5 ). At the base of the pterygopalatine fossa, the greater The pterygomaxillary fi ssure transmits the maxillary and lesser palatine nerves, which arise from the pterygopala- artery from the infratemporal fossa. The fi ssure continues tine ganglion together with accompanying vessels (greater above with the posterior end of the inferior orbital fi ssure in and lesser palatine arteries), pass into the hard palate to the fl oor of the orbit.

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V1 Nerve to inferior oblique m. (III) Inferior ophthalmic v. Inferior orbital fissure Infraorbital n., a. V2 Pterygopalatine ganglion Posterior superior alveolar a., n. Nerve of pterygoid canal Orifice of maxillary sinus V3 (GSPN, Deep petrosal n.), A., V. of the pterygoid canal

Posterior trunk of V3 Posterior superior alveolar a., n.

Tensor veli palatini m.

Buccal n. Maxillary a.

Buccinator m.

Fig. 10.15. The nerve of pterygoid canal. The pterygoid canal, orbit, and maxillary sinus have been opened.

The pterygoid canal (also known as the vidian canal) is a carotid plexus and appear as the deep petrosal nerve. The passage in the skull leading from just anterior to the foramen deep petrosal nerve innervates the blood vessels of the lacri- lacerum in the middle cranial fossa to the pterygopalatine mal gland. The fi bers do not synapse at the ganglion and pass fossa. The greater petrosal nerve (preganglionic parasympa- to the lacrimal gland along the same course as the parasym- thetic), the deep petrosal nerve (postganglionic sympathetic), pathetic innervation. and accompanying vessels (artery and vein of the pterygoid The buccal nerve courses between the two heads of the canal), which originate from the pterygopalatine segment of lateral pterygoid muscle (see Fig. 10.2 , Fig. 10.3 , and Fig. the maxillary artery, enter the pterygoid canal. On leaving the 10.4) underneath the tendon of the temporalis muscle and pterygoid canal, the nerves emerge into the pterygopalatine then under the masseter muscle to connect with the zygo- fossa and join the pterygopalatine ganglion. From the supe- maticobuccal branches of the facial nerve on the surface of rior cervical ganglion, sympathetic fi bers pass to the internal the buccinator muscle (see Fig. 11.6 ).

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Chorda tympani (Spine of sphenoid bone has been removed.) Mandibular n., Mastoid tip Middle meningeal a. Vaginal process Stylomastoid a. Facial n. (reflected posteriorly) Styloid process (cut) Levator veli palatini m. Occipital a. (cut) Ascending pharyngeal a. Internal carotid a. Rectus capitis lateralis m.

Accessory n. External carotid a. (reflected) Transverse process of atlas Superior pharyngeal Internal jugular v. constrictor m. Hypoglossal n. Glossopharyngeal n. Pharyngeal plexus Levator scapulae m. Vagus n.

Fig. 10.16. Structures adjacent to the facial nerve trunk. The styloid process has been cut and the facial nerve has been refl ected laterally.

The stylomastoid artery, which generally originates from the lateral surface), and runs then backward and downward to posterior auricular artery or the occipital artery, supplies the reach the upper part of the sternocleidomastoid muscle (see facial nerve trunk and enters into the skull, close to the facial Fig. 12.3). Approximately 30% of nerves descend along the nerve, through the stylomastoid foramen. medial, rather than the lateral, surface of the internal jugular The hypoglossal nerve passes between the internal jugular vein. The spinal accessory nerve provides motor innervation vein and the internal carotid artery to the level of the trans- to two muscles of the neck: the sternocleidomastoid and the verse process of the atlas, where it turns abruptly forward trapezius. along the lateral surface of the internal carotid artery toward The glossopharyngeal nerve leaves the skull through the the tongue, leaving only the ansa cervicalis to descend with jugular foramen and passes between the internal jugular vein the major vessels. It then runs anteriorly between the internal and the internal carotid artery. The glossopharyngeal nerve and external carotid arteries and onto the stylopharyngeus is mostly sensory, with only one motor component. Glosso- muscle. It passes below the submandibular gland onto the pharyngeal nerve gets pain, temperature, and touch from the hyoglossus muscle to be distributed to the muscle of the tongue, ear, insides of the throat, and so on. It gets taste from tongue (see Fig. 12.2). The hypoglossal nerve is a source of the back one-third of the tongue. axons for facial reinnervation when the proximal facial nerve The pharyngeal plexus, with fi bers from CN IX, CN X, and stump is not available but the distal facial nerve and facial cranial part of CN XI, innervates all the muscles of the pharynx musculature are present and functional. except the stylopharyngeus muscle, which is innervated by Through the jugular foramen, the accessory nerve descends CN IX. The plexus provides sensory innervation of the oro- obliquely, crosses the internal jugular vein (usually on its pharynx and laryngopharynx.

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Mandibular fossa (opened) Semicircular canals Sigmoid sinus Handle of malleus Superficial temporal a., Auriculotemporal n. Chorda tympani Chorda tympani Tympanomastoid suture (Spine of sphenoid bone has been removed.) Digastric ridge Digastric groove Deep temporal a.

N. to digastric m., Maxillary a. Posterior auricular n. Chorda tympani Facial n. Lingual n. Stylomastoid a.

Posterior auricular a. Tensor veli palatini m. Accessory n. Styloid process Occipital a.

Fig. 10.17. Structures adjacent to the facial nerve trunk. The tympanic membrane has been removed to show the course of the chorda tympani.

The chorda tympani is given off just before the stylomastoid membrane. It passes between the malleus and the incus on foramen from the mastoid segment of the facial nerve. This the medial surface of the neck of the malleus. The nerve is the branch from the nervus intermedius. It contains para- continues through the petrotympanic fi ssure, after which it sympathetic fi bers going to the submandibular ganglion and emerges from the skull into the infratemporal fossa. It soon taste fi bers from the anterior two-thirds of the tongue. The combines with the lingual nerve at the infratemporal fossa. nerve initially runs within its own canal before entering The digastric ridge, which is a ridge of bone, corresponds the tympanic cavity. It travels through the middle ear, where to the digastric groove and marks the location of the facial it runs from posterior to anterior across the tympanic canal just anterior to it.

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Middle meningeal a.

Chorda tympani (Spine of sphenoid bone has been removed.)

Eustachian tube (opened) Vaginal process Facial n. Lingual n. Stylomastoid a. Styloid process (cut) Levator veli palatini m. Ascending pharyngeal a.

Maxillary a.

Accessory n. Internal carotid a. Glossopharyngeal n. Internal jugular v. Pharyngeal br. of vagus n. Hypoglossal n.

Fig. 10.18. Structures adjacent to the facial nerve trunk. The Eustachian tube has been opened.

The ascending pharyngeal artery is the smallest branch of the The middle meningeal artery is the main source of blood external carotid artery. It arises from the posterior surface of to the meninges and to the bones of the vault of the skull. It the external carotid artery, passing vertically upward to the ascends between the two roots of the auriculotemporal nerve pharynx. It terminates near the base of the skull. The menin- and leaves the infratemporal fossa through the foramen geal branches from the ascending pharyngeal artery enter spinosum. through the foramen lacerum and the hypoglossal canal. Both the jugular foramen and carotid canal are situated The middle cranial fossa is innervated by the meningeal behind the vaginal process, which encloses the root of the branch of the mandibular division of the trigeminal nerve. It styloid process and forms the posterior wall of the condylar enters the cranial cavity through the foramen spinosum. fossa.

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Frontal br. of superficial temporal a. Parietal br. of superficial Frontalis m. temporal a.

Temporoparietal fascia

Corrugator supercilii m. Superior auricular m. Orbicularis oculi m. Auriculotemporal n. Zygomatico-orbital a. Procerus m. Superficial temporal a., v. Temporal brs. Lateral nasal a. Transverse facial a. Zygomatics minor m., Levator labii superioris m. Parotid gland Zygomatic br., Buccal br., parotid gland Zygomatics major m. Levator anguli oris m. Posterior auricular a. Buccinator m. Modiolus Masseteric fascia Premasseteric a. Great auricular n. Marginal mandibular br. Depressor anguli oris m. Facial a., v. Cervical br. Orbicularis oris m. External jugular v. Depressor labii inferioris m. Sternocleidomastoid m.

Platysma m.

Fig. 11.1. Lateral oblique view of the face. The skin has been removed.

The modiolus is a nodular region at the corner of the mouth The levator anguli oris, the buccinator, and the mentalis where several mimetic muscles converge and interlace. It is muscles are deep-seated muscles that are innervated on their contributed by the orbicularis oris, buccinator, levator anguli superfi cial surface by the facial nerve branches. oris, depressor anguli oris, zygomatics major, and risorius The facial vein begins as the angular vein at the medial muscles. corner of the eye. The angular vein is formed by the confl u- The depressor labii inferioris muscle is partly covered ence of the supraorbital and supratrochlear veins. The facial by the anterior fi bers of the depressor anguli oris vein passes downward behind the facial artery independently muscle. to the inferior border of the mandible.

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Buccal brs. (masseteric fascia is opened) Buccinator m. Tail of parotid gland Sternocleidomastoid m. Masseteric fascia Posterior auricular v., posterior br. of Premasseteric artery retromandibular v.

Marginal mandibular br. Lesser occipital n. Great auricular n.

Cervical brs.

Facial a., v. External jugular v.

Anterior br. of retromandibular v. Transverse cervical n.

Fig. 11.2. The lower facial region. Close up view of the parotid tail and mandibular angle.

The marginal mandibular branches of the facial nerve emerge At the inferior border of the mandible near the anterior from the lower border of the parotid gland, and the branch edge of the masseter muscle, the facial artery and the vein runs near the inferior border of the mandible. Initially, it may course closely. pass into the neck below the angle of the mandible, but after The premasseteric artery arises at the lower border of the crossing the facial artery it usually comes up above the lower mandible from the facial artery and ascends along the ante- border of the mandible to the face. It innervates the depressor rior edge of the masseter muscle. anguli oris, the depressor labii inferioris, the mentalis, and The great auricular nerve perforates the deep cervical the lower orbicularis oris muscles. fascia and ascends upon the sternocleidomastoid muscle The cervical branch passes downward from the lower beneath the platysma to the parotid gland, where it divides border of the parotid gland to supply the platysma muscle in into an anterior and a posterior branch. It provides sensory the neck. Some of the its branches frequently innervate innervation for the skin over the parotid gland and the the depressor labii inferioris and the depressor anguli oris mastoid process, as well as both surfaces of the caudal region muscles. of the auricle. One of the buccal branches runs beneath the masseteric fascia in this fi gure. However, most of the marginal mandibu- lar branches generally run on the fascia.

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Zygomaticus major m. Zygomaticobuccal brs. Levator anguli oris m. Lateral nasal a.

Superior labial a. Buccinator m. Modiolus Facial v. Depressor anguli oris m.

Facial a.

Orbicularis oris m.

Inferior labial a.

Fig. 11.3. The lower facial region. Close up view of the oral commissure.

The modiolus may be fi xed by the action of some of The facial artery passes upward and forward from the the muscles to provide a base for the action of other mandible and lies deep to the zygomaticus major muscle and muscles. superfi cial to the buccinator muscle. It lies either superfi cial The orbicularis oris muscle is a complex of muscles in the or deep to the levator anguli oris muscle and levator labii lips that encircle the mouth. This muscle closes the mouth superioris muscle. The branches of the facial artery on the and puckers the lips when it contracts. It is innervated by face are the inferior labial and superior labial. It terminates the zygomaticobuccal branch and the marginal mandibular as lateral nasal arteries or the angular artery. The former two branch. branches are situated deep to the orbicularis oris muscle.

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Inferior alveolar a., v., n. (The mandibular canal Depressor anguli oris m. has been opened) (reflected upward)

Facial a., v.

Inferior labial a. Mylohyoid n. Orbicularis oris m. Marginal mandibular br. Mental n., a., v. Mylohyoid m.

Depressor labii inferioris m. Submental a.

Anterior belly of Depressor anguli oris m. digastric m. Mentalis m. Platysma m.

Fig. 11.4. The lower facial region. The platysma and depressor anguli oris muscles have been removed to leave their attachments.

The mentalis muscle is in the deepest layer among the The platysma muscle is a fl at muscle which inserts into mimetic muscles. It originates from the incisive fossa of the the subcutaneous tissues of the subclavicular and acromial mandible. Its fi bers descend to insert into the skin of the chin. regions inferiorly and then inserts into the chin at the com- This muscle raises and protrudes the lower lip. missures of the mouth and in the anterior one-third of the The depressor labii inferioris muscle arises from the man- oblique line of the mandible. This muscle is a depressor of the dible just in front of the mental foramen. The fi bers pass lower lip innervated by the cervical branch of the facial nerve. upward and medially to converge with the orbicularis oris The digastric muscle stretches between the mastoid process muscle in the lower lip. This muscle depresses the lower lip of the cranium to the mandible. Part of the way between, it and draws it laterally. becomes a tendon that passes through a tendinous pulley The depressor anguli oris muscle arises from an extensive attached to the hyoid bone. The anterior belly of the digastric area around the external oblique line of the mandible. Its muscle arises from a depression on the inner side of the lower fi bers pass upward to the corner of the mouth. This muscle border of the mandible called the digastric fossa, which is close depresses the corner of the mouth. to the symphysis, and passes downward and backward.

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Superficial temporal a. Maxillary a. Mandibular condyle Posterior superior alveolar n., a. Lateral pterygoid m. Posterior belly of Deep facial v. digastric m. Parotid duct Medial pterygoid m.

Lateral nasal a. Lingual n. Zygomaticus major m. Inferior alveolar a., n., v. Levator anguli oris m. Buccinator m. Superior labial a. Facial a. Depressor anguli oris m. Retromandibular v. Facial v. Common facial v. Inferior labial a. Facial a. Submental a. Mental n., a., v. Submandibular gland

Fig. 11.5. The lower facial region. The mandibular canal has been opened.

The buccinator muscle is in the deepest layer among the sensory components. It next enters the mandible with the mimetic muscles, and it functions principally during mastica- vessels via the mandibular foramen. While in the mandibular tion. An important relationship is with the parotid duct, canal within the mandible, the main trunk of the inferior which pierces the muscle opposite the maxillary third molar alveolar nerve divides near the premolars into mental and and then runs forward to open into the oral cavity opposite incisive nerves. The mental nerve and vessels run for a short the maxillary second molar. This muscle has two main origins. distance in a mental canal before leaving the body of the First, it arises from the anterior margin of the pterygoman- mandible at the mental foramen to emerge onto the face. It dibular raphe. Second, it is attached to the alveolar margins supplies the skin and mucosa of the lower lip and the labial of the maxilla and mandible in the region of the molar teeth. gingivae of the mandibular anterior teeth. The mental nerve The fi bers eventually run into the orbicularis oris muscle. has communication with the marginal mandibular branch of The inferior alveolar nerve arises from the mandibular the facial nerve. The mental artery arises from the mandibu- nerve and emerges from beneath the lateral pterygoid muscle. lar segment of the maxillary artery as a terminal branch of Then, it gives off a mylohyoid branch which has motor and the inferior alveolar artery.

c11.indd 85 2/10/2015 1:40:42 PM 86 III Lower Facial and Posterolateral Neck Region

Zygomaticus major m. Auriculotemporal n. Masseteric a., n.

Tendon of temporalis m. Facial n.

Ascending ramus Parotid duct

Buccal a.

Buccinator m.

Buccal n. Masseteric n.

Masseter m. (reflected)

Fig. 11.6. The lower facial region. The masseter muscle has been refl ected inferiorly to show the ascending ramus of mandible.

The buccal nerve runs into the upper part of the retromolar The buccal artery is a branch of the pterygoid segment fossa at the anterior border of the ramus of the mandible. The of the maxillary artery. It emerges onto the face from the buccal nerve divides into several branches within the bucci- infratemporal fossa and crosses the buccinator muscle to nator muscle. It innervates both the mucosa and the skin of supply the cheek. The masseteric artery is also a branch of the cheek and buccal gingivae of the mandibular cheek teeth. the pterygoid segment of the maxillary artery and courses The buccal nerve has communication with zygomaticobuccal close to the same nerve anteroinferiorly in the masseter branches of the facial nerve. muscle.

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Lateral pterygoid m. Infraorbital n. External carotid a. Zygomaticobuccal br. Posterior belly of of facial n. digastric m. Lateral nasal a. Lingual n. Parotid duct (probe is Septal a. in the duct) Buccinator m. Columellar a. Inferior alveolar n., a. Superior labial a. Mandible

Internal jugular v. Tongue Facial a., v. Submandibular gland Inferior labial a. Common facial v. Mental n., a, v. Submental a. Mylohyoid n. Mentalis m. Anterior belly of Depressor anguli oris m. digastric m. Platysma m.

Fig. 11.7. The lower facial region. The upper and lower lip have been removed to leave the facial artery.

The facial artery usually lies anterior to the facial vein through- anguli oris muscle and, penetrating the orbicularis oris out its course and courses close to the vein on the mandible. muscle, runs in a tortuous course along the edge of the lower The superior labial artery is larger and more egregious lip between this muscle and the mucous membrane. It sup- than the inferior labial artery. It courses along the edge of the plies the labial glands, the mucous membrane, and the upper lip, lying between the mucous membrane and the orbi- muscles of the lower lip, and it anastomoses with the artery cularis oris muscle, and it anastomoses with the artery of the of the opposite side opposite side. It supplies the upper lip and gives off in its The submental artery is a branch of the facial artery, given course two branches that ascend to the nose: a septal branch off just as that vessel leaves the submandibular gland. It runs ramifi es on the nasal septum and a columellar branch sup- forward upon the mylohyoid, just below the body of the man- plies the columella of the nose. dible and beneath the digastric muscle. It supplies the sur- The inferior labial artery arises near the angle of the rounding muscles and also a territory of skin in the submental mouth. It passes upward and forward beneath the depressor area.

c11.indd 87 2/10/2015 1:40:44 PM 12 Oral Floor and Upper Neck Region

Inferior alveolar n., a., v.

Posterior belly of digastric m.

Tongue Lingual n.

Facial a., v. Ducts of sublingual gland Submandibular ganglion Hyoglossus m. Sublingual gland Mylohyoid n. Hypoglossal n. Common facial v. Mylohyoid m. Sublingual a. Internal jugular v. Geniohyoid m. Submandibular Gland

Submental a. Anterior belly of digastric m.

Fig. 12.1. The oral fl oor from the side. Part of the mandible has been removed.

The submandibular ganglion is parasympathetic ganglion the mylohyoid muscle and the anterior belly of digastric that is found in the fl oor of the mouth on the superfi cial muscle. It also supplies the skin of the submental region. surface of the hyoglossus muscle. It lies between the lingual The lingual nerve courses toward the fl oor of the mouth nerve and the deep part of the submandibular gland. It from the infratemporal fossa. It supplies the mucosa covering is suspended by two roots from the lingual nerve. The sub- the anterior two-thirds of the dorsum of the tongue, the mandibular ganglion is responsible for innervation of the ventral surface of the tongue, the fl oor of the mouth, and the submandibular gland and sublingual gland. Preganglionic lingual gingivae of the mandibular teeth. The rest of the pos- parasympathetic fi bers originate from the superior salivary terior part of the tongue are innervated by the glossopharyn- nucleus in the brain stem. The fi bers pass with the nervus geal nerve. intermedius of the facial nerve into the internal acoustic The mylohyoid muscle arises from the mylohyoid line on meatus and exit the skull with the chorda tympani at the the medial surface of the body of the mandible. Its fi bers petrotympanic fi ssure. The chorda tympani nerve joins the interdigitate with the contralateral fi bers to form a medial lingual nerve. raphe. This raphe is attached above to the mandible and The inferior alveolar nerve branches off the mylohyoid below to the hyoid bone. The muscle raises the fl oor of the nerve before entering the mandibular canal. The mylohy- mouth during the fi rst stages of swallowing. It also helps to oid nerve courses inferiorly and anteriorly in the mylohyoid depress the mandible when hyoid bone is fi xed. Conversely, groove beneath the mylohyoid line (see Fig. 3.7 ). It supplies it aids in elevation of the hyoid bone.

c12.indd 88 2/10/2015 1:40:46 PM 12 Oral Floor and Upper Neck Region 89

Cerebellum Facial n. Auricular br. of posterior Stylomastoid a. auricular a. Posterior auricular a. Occipital a. Mandible

Stylomandibular ligament Accessory n. Stylopharyngeus m. Internal carotid a. Ascending pharyngeal a. Internal jugular v. Pharyngeal plexus (displaced laterally) Ascending palatine a. Tongue Sternocleidomastoid m. Mylohyoid n. (cut and reflected) Lingual a. Upper root of ansa cervicalis Styloglossus m. Glossopharyngeal n. Vagus n. Lingual n. Cervical plexus Facial a. Superior laryngeal n. Hypoglossal n. Hyoglossus m. Common carotid a. Submental a. Superior thyroid a.

Fig. 12.2. The upper neck region. The branches of the external carotid artery.

The common carotid artery divides at the upper border of the The ascending pharyngeal artery is the smallest branch of thyroid cartilage, which is generally on a level with the upper the external carotid artery. It is a long, slender vessel, deeply border of the fourth cervical vertebra. At its origin, the exter- seated in the neck beneath the other branches of the external nal carotid artery is actually anteromedial to the internal carotid and under the stylopharyngeus muscle. It arises from carotid artery. The external carotid artery ascends anteriorly the posterior surface of the external carotid artery and passes to the internal carotid artery through the parotid gland, deep vertically upward between the internal carotid and the side to the retromandibular vein. Proximal to its terminal bifurca- of the pharynx to under the surface of the base of the skull, tion into the maxillary and the superfi cial temporal arteries, lying on the longus capitis muscle. it gives rise to six branches: the superior thyroid artery, the The lingual artery arises from the external carotid artery ascending pharyngeal artery, the lingual artery, the facial just above the superior thyroid artery and passes beneath the artery, the occipital artery, and the posterior auricular artery. hyoglossus muscle to enter the tongue. Its branches are the The superior thyroid artery is the fi rst branch of the exter- infrahyoid artery and the sublingual artery, with the deep nal carotid artery. It arises at the level of the greater horn of lingual artery as its terminal branch. the hyoid bone and supplies the thyroid, the sternocleido- mastoid muscle, and the larynx.

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Retromandibular v. Cerebellum Mastoid process Posterior auricular a. (digastric groove) Facial n. (main trunk) Temporofacial division Br. to digastric m. and stylohyoid m. (facial n.) Cervicofacial division Occipital a. Digastric m. (posterior belly) Superior oblique m.

Sternocleidomastoid br. of occipital a. Masseter m. Accessory n. (br. to sternocleidomastoid m.) Hypoglossal n. Facial a. Internal jugular v. Stylohyoid m. Vagus n. Anterior br. of the retromandibular v. Internal carotid a. Superior thyroid a. Facial a., v. Ansa cervicalis Submandibular gland Sternocleidomastoid m. (reflected) Common facial v.

Fig. 12.3. The lower facial and upper neck region. Suboccipital craniotomy has been done and the posterior belly of the digastric muscle has been detached from the digastric groove.

The branches of the facial nerve to the posterior belly of the hyoid muscle, including the sternothyroid muscle, the sterno- digastric and stylohyoid muscles arise close to the stylomas- hyoid muscle, and the omohyoid muscle. toid foramen. The stylohyoid muscle is inserted into the body The facial artery arises from the external carotid artery of the hyoid bone. When it contracts, it elevates the hyoid. immediately above the greater horn of the hyoid bone. It runs This action is primarily brought about during swallowing. The upward behind the submandibular gland deep to the stylo- muscle is perforated near its insertion by the intermediate hyoid muscle and posterior belly of digastric muscle. Above tendon of the digastric muscle. the stylohyoid muscle, it turns downward and forward The ansa cervicalis is a loop of nerves that are part of the between the lateral surface of the submandibular gland and cervical plexus. The upper root of the ansa cervicalis is derived the medial pterygoid muscle to reach the lower border of the from the ventral ramus of the fi rst cervical nerve. This branch mandible. fi rst appears as the hypoglossal nerve loops around the occip- The vagus nerve exits through the jugular foramen and ital artery. It passes down on the carotid sheath covering the passes into the carotid sheath between the internal carotid carotid arteries and is joined by the lower root of the ansa artery and the internal jugular vein down below the head to cervicalis from the cervical plexus to form the ansa cervicalis. the neck, the chest, and the abdomen, where it contributes to Branches from the ansa cervicalis innervate most of the infra- the innervation of the viscera.

c12.indd 90 2/10/2015 1:40:47 PM 13 Posterior Neck and Occipital Region

Cranium Pericranium

Occipitalis m. Ascending br. of occipital a. Inion Medial br. of Transverse br. greater occipital n. of occipital a. Lateral br. of Tendinous arch greater occipital n. Descending br. of occipital a.(cutaneous br.) Splenius capitis m. Lesser occipital n. Posterior auricular v. Posterior auricular a. Lesser occipital n. Dorsal rami of cervical n. (C3~C5) Sternocleidomastoid m.

Trapezius m.

Fig. 13.1. The posterior neck region. The skin and the galea have been removed to leave the occipitalis muscle on the left side.

The occipitalis muscle has two muscle bellies that are sepa- superior nuchal line. It supplies the skin over the occipital rated in the midline by the aponeurosis. Each occipital belly part of the scalp up to the vertex of the skull. arises from the lateral two-thirds of the supreme nuchal line The lesser occipital nerve has a variable origin either from of the occipital bone and from the mastoid process of the the second or the second and third cervical ventral rami. The temporal bone. The muscle extends forward to become con- lesser occipital nerve lies at approximately 7 cm lateral to the tinuous with the galea aponeurotica. It is a part of the occipi- external occipital protuberance. This nerve supplies the skin tofrontalis muscle, along with the frontalis muscle. It is over the scalp and cranial surface of the upper part of the innervated by the posterior auricular branch of the facial auricle. nerve. Its function is to move the scalp back. The medial branches of the dorsal rami of the third, fourth, The greater occipital nerve and occipital artery reach the and fi fth cervical nerves pierce the trapezius muscle at subcutaneous tissues by passing between the attachment its paramedian position to supply skin over the back of the of the trapezius and sternocleidomastoid muscles to the neck. superior nuchal line. The occipital artery crosses deep to The trapezius muscle covers the back of the head and neck. the greater occipital nerve approximately 4 cm lateral to the It extends from the medial half of the superior nuchal line, external occipital protuberance (inion). After it pierces the the external occipital protuberance, and the spinous pro- deep fascia, it gives rise to three major cutaneous branches: cesses of the cervical and thoracic vertebrae and converges descending, transverse, and ascending. The greater occipital on the shoulder to attach to the scapula and the lateral third nerve branches into medial and lateral branches around the of the clavicle.

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Midline

Parietal foramen

c a

Parietal br. of Parietal br. of superficial temporal a. superficial temporal a.

Anastomotic a.

Galea Occipital a. Occipital a.

b Midline Fig. 13.2a-c. (a) The scalp from above. The skin has been removed to show the galea. (b) The scalp from above. The scalp without pericranium has been reversed. (c) The skull from above.

The branches from the superfi cial temporal, posterior auricu- or both sides. The vertical distance from the inion to the level lar, occipital, supraorbital, and supratrochlear arteries freely of the parietal foramen is approximately 8 cm, and the anastomose in the scalp. distance from the midline to the foramen is within 10 mm This fi gure shows the meningeal branch (anastomotic ( Fig. 13.2c ). artery) from the occipital artery bilaterally which is passing The superfi cial temporal artery that supplies the galea through the parietal foramen. The well-developed anasto- does not cross the midline or anastomose with the contralat- motic artery is found in approximately 50% of specimens, and eral superfi cial temporal artery on the galeal layer. The it develops the vascular network of the galea and scalp. The vein on the galea generally runs superfi cially on the artery rich vascular connection in the galea and scalp contributes except for the vertex region. The artery in the vertex region rich vascularity to galeal and scalp fl ap in the head. courses more superfi cially on the vein and anastomoses The parietal foramen is found in more than 60% of with the contralateral artery in the subcutaneous layer (Fig. skulls. It may be unilateral or bilateral or duplicate on one 13.2a ).

c13.indd 92 2/10/2015 1:40:51 PM 13 Posterior Neck and Occipital Region 93

Perforating artery from posterior auricular a. Arnold’s nerve

b

Occipitalis m.

Occipital a. Posterior auricular m.

Posterior auricular v.

Tendinous arch Posterior auricular n.

Greater occipital n. Occipital br. of posterior auricular a. Parotid gland Splenius capitis m. Great auricular n. Lesser occipital n.

Sternocleidomastoid m.

a

Fig. 13.3a,b. (a) The posterior neck region. (b) Lateral view of the auricular cartilage.

The posterior auricular nerve is the fi rst extracranial branch occipital muscles. The posterior auricular muscle arises from of the facial nerve. It originates from the facial nerve close to the mastoid bone and inserts into cranial surface of the the stylomastoid foramen and then courses posteriorly and concha. It displaces the auricle backward. upward on the surface of the mastoid bone. There, it is joined The occipital branch of the posterior auricular artery runs by a fi lament from the auricular branch of the vagus (see the back over the insertion of sternomastoid muscle to supply the text accompanying Fig. 2.2 ), which supplies the auricular skin of behind the ear. The posterior auricular vein is variable. concha as the Arnold’ s nerve ( Fig. 13.3b ) and communicates The well-developed posterior auricular vein might be found with the posterior branch of the great auricular, as well as the to compensate for the underdeveloped superfi cial temporal lesser occipital, nerve. It supplies the posterior auricular and vein (see Fig. 4.2 ).

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Temporalis m.

Sternocleidomastoid m. Occipital a. Medial br. of greater occipital n.

Lateral br. of greater occipital n. Semispinalis capitis m.

Greater occipital n. Posterior auricular v.

Auricular br. of Splenius capitis m. posterior auricular a. Trapezius m. Great auricular n. Occipital br. of posterior auricular a. Lesser occipital n.

Fig. 13.4. The posterior neck region. The galea and occipitalis muscle have been removed.

The sternocleidomastoid muscle passes obliquely downward muscle and passes through or deep to it to emerge into the across the side of the neck from the lateral half of superior posterior triangle on the way to the trapezius muscle (see nuchal line and mastoid process to the upper part of the Fig. 12.3 ). sternum and adjacent part of the clavicle. The sternocleido- The sternocleidomastoid muscle divides the side of the mastoid muscle is innervated by the accessory nerve. The neck into an anterior triangle and a posterior triangle. The function of this muscle is to rotate the head to the opposite anterior triangle is bounded posteriorly by the anterior border side or obliquely rotate the head. When the muscle and nerve of the sternocleidomastoid, above by the mandible, and ante- act together, the neck fl exes and the head extends. The ster- riorly by the median line of the neck; the posterior triangle is nocleidomastoid branches of the occipital artery supply the bounded in front by the posterior border of the sternocleido- cephalic end of sternocleidomastoid muscle. The spinal part mastoid, below by the middle third of the clavicle, and behind of the accessory nerve supplies the sternocleidomastoid by the anterior margin of the trapezius muscle.

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Temporalis m.

Occipital a.

Semispinalis capitis m. Mastoid process

Greater occipital n. Posterior auricular v. Auricular br. of posterior auricular a. Splenius capitis m. Facial n., Parotid gland Posterior auricular a. Digastric m. Transverse process of atlas Accessory n. Lesser occipital n.

Internal jugular v., Carotid a. Trapezius m. Sternocleidomastoid m. (reflected)

Fig. 13.5. The posterior neck region. The sternocleidomastoid muscle has been refl ected laterally.

The posterior auricular artery is a small artery that arises with the superfi cial temporal artery. The auricular branch has from the external carotid artery above the digastric muscle small branches which pierce the auricular cartilage to reach and stylohyoid muscle opposite the apex of the styloid the external surface (see Fig. 13.3b ). process. It ascends over the digastric muscle between the The splenius capitis, situated deep to and partially covered auricular cartilage and the mastoid process, pierces the deep by trapezius and sternocleidomastoid, extends from the bone fascia at the level of the external auditory meatus, and divides below the lateral third of the superior nuchal line to the into auricular and occipital branches. The auricular branch spinous processes of the lower cervical and upper thoracic ascends deep to posterior auricular muscle and anastomoses vertebrae.

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Temporalis m.

Asterion

Occipital a. Mastoid emissary v., Meningeal br. of occipital a. Transverse br. of occipital a. Mastoid process (cutaneous br.)

Longissimus capitis m. Auricular br. of posterior auricular a. Greater occipital n. Facial n., Parotid gland Descending br. of occipital a. (muscle br.) Posterior auricular a Digastric m. Transverse process of atlas Semispinalis capitis m. Levator scapulae m. Accessory n. Trapezius m., Sternocleidomastoid m. Splenius capitis m. (reflected)

Fig. 13.6. The posterior neck region. The splenius capitis and trapezius muscle have been refl ected medially.

The mastoid foramen is a large hole in the posterior border and sternocleidomastoid muscle, attaches above to the pos- of the temporal bone. It transmits a mastoid emissary vein terior margin of the mastoid process. connecting the sigmoid sinus and a small meningeal branch The greater occipital nerve ascends obliquely between the of the occipital artery, the posterior meningeal artery, to the inferior oblique and the semispinalis capitis muscle. It pierces dura mater. the semispinalis capitis and the trapezius muscles near their The semispinalis capitis muscle, situated deep to the sple- attachments to the occipital bone. It supplies the semispinalis nius capitis and sternocleidomastoid muscle, attaches below capitis muscle, ascends with the occipital artery, and supplies to the upper thoracic and lower cervical vertebrae. The lon- the scalp as far forward as the vertex. gissimus capitis muscle, situated deep to the splenius capitis

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Ascending br. of occipital a. Temporalis m. (cutaneous br.)

Superior nuchal line

Transverse br. of occipital a. (cutaneous br.)

Digastric m. Mastoid process Occipital a. Great auricular n. Greater occipital n. Facial n. Descending brs. of occipital Superior oblique m. a. (muscle br.) Semispinalis capitis m. Inferior oblique m. Transverse process of atlas Trapezius m., Sternocleidomastoid m. Splenius capitis m.

Longissimus capitis m.

Fig. 13.7. The posterior neck region. The longissimus capitis muscle has been refl ected inferiorly.

The occipital artery arises from the posterior surface of the pierce that muscle to supply the trapezius muscle. The deep external carotid opposite the facial artery and runs posteri- portion runs down between the semispinalis capitis muscle orly. At its origin, it is crossed by the hypoglossal nerve. On and anastomoses with the vertebral artery. its way to the mastoid process, it crosses the internal carotid The suboccipital muscles, located in the next layer, are a artery, the internal jugular vein, and the hypoglossal and group of muscles situated deep to the splenius, semispinalis, spinal accessory nerves. It passes beneath the lower portion and longissimus capitis in the suboccipital area. This group of the parotid gland. It runs horizontally backward through includes the superior oblique, which extends from the area the occipital groove of the temporal bone, covered by all the lateral to the semispinalis capitis between the superior and muscles attached to the mastoid process: the sternocleido- inferior nuchal lines to the transverse process of the atlas; the mastoid, splenius capitis, and the posterior belly of the digas- inferior oblique, which extends from the spinous process and tric. It lies upon the superior oblique and semispinalis capitis lamina of the axis to the transverse process of the atlas; the muscle. The artery reaches the subcutaneous tissue by passing rectus capitis posterior major, which extends from and below between the attachment of the trapezius and sternocleido- the lateral part of the inferior nuchal line to the spine of the mastoid muscle to the superior nuchal line. axis; and the rectus capitis posterior minor, which is situated The descending branch of occipital artery, the largest medial to and is partially covered by the rectus capitis poste- branch of the occipital, descends on the back of the neck and rior major, and extends from the medial part and below the divides into a superfi cial and deep portion. The superfi cial inferior nuchal line to the tubercle on the posterior arch of portion runs beneath the splenius, giving off branches that the atlas.

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Temporalis m.

Superior nuchal line

Digastric m.

Occipital a. Inferior nuchal line Facial n. Rectus capitis posterior minor m. Superior oblique m. Descending br. of occipital a. Rectus capitis posterior major m.

Ventral ramus of C2 Inferior oblique m. Vertebral a. Greater occipital n. Levator scapulae m. (dorsal ramus of C2)

Fig. 13.8. The posterior neck region. The semispinalis capitis muscle has been refl ected inferiorly.

The suboccipital triangle is a region bounded above and medi- inferior oblique muscle, the dorsal ramus divides into a large ally by the rectus capitis posterior major, above and laterally medial branch and a small lateral branch. It is the medial by the superior oblique, and below and laterally by the inferior branch that forms the greater occipital nerve. The lateral oblique. The fl oor of the triangle is formed by the posterior branch sends fi laments that innervate the splenius, longissi- atlanto-occipital membrane and the posterior arch of the atlas. mus, and semispinalis capitis, and is often joined by the cor- The structures in the triangle are the terminal extradural responding branch from the C3 nerve. The C2 ventral ramus segment of the vertebral artery and the fi rst cervical nerve. courses between the vertebral arches and transverse pro- The C2 nerve emerges between the posterior arch of the cesses of the atlas and axis and behind the vertebral artery. atlas and the lamina of the axis where the spinal ganglion is Two branches of the C2 and C3 ventral rami, the lesser occipi- located extradurally, medial to the inferior facet of C1 and the tal and great auricular nerves, curve around the posterior vertebral artery. The nerve divides into a large dorsal and a border and ascend on the sternocleidomastoid muscle to smaller ventral ramus. After passing below and supplying the supply the skin behind the ear.

c13.indd 98 2/10/2015 1:40:55 PM 13 Posterior Neck and Occipital Region 99

Mastoid process

Digastric m.

Superior oblique m.

Occipital a. Descending br. of occipital a. Facial n., Parotid gland Rectus capitis posterior major Dorsal ramus of C1 Vertebral venous plexus

Br. to inferior oblique m. Transverse process of atlas

Ventral ramus of C2 Vertebral a. Inferior oblique m. Sternocleidomastoid m. (reflected)

Fig. 13.9. The posterior neck region. The innervation to the muscles from dorsal ramus of C1 is shown.

The C1, C2, and C3 nerves divide into dorsal and ventral rami. where it sends branches to the rectus capitis posterior major The dorsal rami divide into medial and lateral branches that and minor, the superior and inferior oblique, and the semi- supply the skin and muscles of the posterior region of the spinalis capitis. Occasionally, it has a cutaneous branch that neck. The C1 nerve, called the suboccipital nerve, leaves the accompanies the occipital artery to the scalp. The C1 ventral vertebral canal between the occipital bone and atlas and has ramus courses between the posterior arch of the atlas and the a dorsal ramus that is larger than the ventral ramus. The vertebral artery and passes forward, lateral to the lateral mass dorsal ramus courses between the posterior arch of the atlas of the atlas and medial to the vertebral artery, and supplies and the vertebral artery to reach the suboccipital triangle, the rectus capitis lateralis.

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Temporal fascia

Asterion

Middle temporal a.

Posterior edge of external acoustic meatus

Mastoid emissary v., Meningeal br. of occipital a.

Posterior auricular v. Digastric m.

Facial n.

Auricular br. of Occipital a. (dissected from the groove) posterior auricular a.

Posterior auricular a. Superior oblique m.

Fig. 13.10. Lateral view of the mastoid.

The posterior belly of the digastric muscle arises from bone is being held in place (by the infrahyoid muscles), it will the mastoid notch (digastric groove), which is on the inferior tend to depress the mandible (open the mouth). The stylo- surface of the skull, medial to the mastoid process of mastoid foramen is at the anterior end of the digastric notch. the temporal bone. The posterior belly is supplied by the The asterion, defi ned as the junction among the lambdoid, digastric branch of facial nerve. When the digastric muscle parietomastoid, and occipitomastoid sutures, is used as a contracts, it acts to elevate the hyoid bone. If the hyoid landmark for the transverse-sigmoid sinus junction.

c13.indd 100 2/10/2015 1:40:57 PM 13 Posterior Neck and Occipital Region 101

Sigmoid sinus

Mastoid segment Temporal br. Digastric m. Zygomatic br. Transverse facial a. Occipital a. Buccal br. Auricular br. of posterior auricular a. Zygomaticobuccal brs. Transverse process of atlas Temporofacial division

Cervicofacial division Greater occipital n. Marginal mandibular br. Cervical br.

Fig. 13.11. The posterior neck region. The superfi cial lobe of the parotid gland has been removed and mastoidectomy has been completed.

After emerging from the base of the skull at the stylomastoid the temporal, zygomatic, buccal, marginal mandibular, and foramen, the facial nerve gains access to the face by passing cervical branches. The Inferior branches of the zygomatic through the substance of the parotid gland. branch usually form a zygomaticobuccal plexus with the The branches in the face include the posterior auricular buccal branches (see Fig. 7.5 ) . nerve, the nerve to the digastric and stylohyoid muscles, and

c13.indd 101 2/10/2015 1:40:57 PM 14 Lateral Neck Region

Lesser occipital n

Prevertebral fascia Erb’s point Accessory n. b

Greater occipital n.

Posterior auricular v.

Lesser occipital n.

Splenius capitis m.

Sternocleidomastoid m.

Accessory n.

Great auricular n.

Supraclavicular n.

External jugular v. Vagus n. a

Fig. 14.1a,b. (a) The lateral neck region. (b) Posterolateral view of the posterior triangle.

The cervical plexus is a plexus of the ventral rami of the fi rst fascia near the cranium to supply the skin over the lateral four cervical spinal nerves, which are located from C1 to C4 scalp and posterior surface of the auricle. The great auricular in the cervical segment in the neck. The branches of the cervi- and transverse cervical nerves only just enter the posterior cal plexus emerge from the posterior triangle at Erb ’ s point, triangle, turning sharply around the posterior border of the a point midway on the posterior border of the sternocleido- sternocleidomastoid muscle (Erb ’ s point). The supraclavicular mastoid. The cervical plexus has two types of branches: cuta- nerves emerge from beneath the sternocleidomastoid and neous and muscular. The cutaneous branches are the lesser pass across and down the posterior triangle toward the clav- occipital nerve (C2), the great auricular nerve (C2, 3), the icle. The transverse cervical nerve supplies the skin antero- transverse cervical nerve (C2, 3), and the supraclavicular lateral parts of the neck. The supraclavicular nerves supplies nerves (C3, 4). The muscular branches are the ansa cervicalis, the skin over the pectoralis major and deltoideus and upper phrenic, and segmental. and posterior parts of the shoulder. The lesser occipital nerve arises from the lateral branch of The prevertebral fascia is prolonged downward and later- the ventral ramus of the second cervical nerve (C2). It curves ally behind the carotid vessels and in front of the scaleni and around the accessory nerve and ascends along the posterior forms a sheath for the brachial nerves and subclavian vessels border of the sternocleidomastoid, where pierces the deep in the posterior triangle of the neck.

c14.indd 102 2/10/2015 1:41:00 PM 14 Lateral Neck Region 103

Posterior auricular v. Greater occipital n. Temporal br. Lesser occipital n.

Posterior auricular a. Parotid gland

Sternocleidomastoid m. Splenius capitis m.

Accessory n.

Great auricular n.

External jugular v.

Transverse cervical n. Supraclavicular n.

Internal jugular v. Vagus n.

Fig. 14.2. The lateral neck region. The sternocleidomastoid muscle has been retracted anteriorly to show the cervical plexus.

The great auricular nerve is derived from the anterior rami of The accessory nerve also emerges from sternocleidomas- the C2 and C3 nerves. It appears at the posterior border of the toid muscle into the posterior triangle. The accessory sternocleidomastoid muscle and passes forward and upward nerve is found approximately 1cm above Erb’ s point. It runs across the muscle to reach the angle of the mandible on and obliquely downward on the levator scapulae muscle to enter beneath the parotid fascia. It supplies the skin overlying the trapezius. mastoid process, lower part of the auricle, the parotid region, The external jugular vein lies on the lateral surface of the and the angle of the mandible. The great auricular nerve and sternocleidomastoid muscle. It arises by the confl uence of the sural nerve are the most commonly selected nerves for facial posterior branch of the retromandibular vein and posterior nerve grafting, but only 7 to 10 cm of the great auricular nerve auricular vein. It drains into the subclavian vein or internal can be harvested safely, which limits its use in extensive jugular vein (see Fig. 11.2 ) . repairs. Disadvantages include a sensory defi cit of the earlobe when using the great auricular nerve.

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A Buccal nerve, 49, 62, 63, 65, 66, 69, 71, 72, Cranial nerve X, 76 Abducens nerve, 11 73, 75, 86 Cranial nerve XI, 76 Accessory meningeal artery, 4, 63, 66 Buccinator muscle, 17, 21, 22, 39, 41, 54, Craniotomy Accessory nerve, 7, 22, 67, 69, 70, 77, 78, 56, 60, 63, 66, 75, 81, 82, 83, 85, frontotemporal, 9 89, 90, 94, 95, 96, 102, 103 86, 87 facial nerve temporal branch in, 37 Alar cartilage, 45, 48 attachment, 65, 68 suboccipital, 90 Alveolar canals, 73 in facial region, 42 Cranium, 92 Anastomatic artery, 92 as modiolus component muscle, 81 Cribiform plate, 13 Angular artery, 46, 83 foramina, 11 Angular vein, 45, 81 C superior view, 13 Ansa cervicalis, 90, 102 Calvarial bones, 9 Crista galli, 11, 13 upper root, 89 Canine eminence, 16 Anterior clinoid process, 11 Canine fossa, 16 D Anterior deep temporal artery, 62 Carotid artery. See also External carotid Deep auricular artery, 63, 67 Anterior deep temporal nerve, 62 artery; Internal carotid artery Deep facial nerve, 68, 69, 85 Anterior ethmoidal artery, 48 in posterior neck region, 95 Deep facial vein, 63, 64, 65 Anterior ethmoidal foramen, 13 Carotid canal, 7, 8, 78 Deep petrosal nerve, 75 Anterior ethmoidal groove, 13 Carotid groove, 11 Deep temporal artery, 61, 63, 64, 65, 66, Anterior ethmoidal nerve, 26, 48 Cervical branch, 39, 43 67, 68, 69, 71, 72, 73, 74, 77 Anterior inferior cerebellar artery, 4 Cervical 1 (C1) nerve Deep temporal fat pad, 59 Anterior lacrimal crest, 13 dorsal ramus, 99 Deep temporal nerve, 49, 54, 61, 63, 64, Anterior nasal spine, 14 ventral ramus, 99 65, 66, 68, 69, 71, 72, 73 Anterior semicircular canal, 3, 4, 5 Cervical 2 (C2) nerve Deep temporal vein, 61 Anterior superior alveolar artery, 49 dorsal ramus, 98, 99 Depressor anguli oris muscle, 17, 22, 39, Anterior superior alveolar nerve, 49 ventral ramus, 98, 99 81, 82, 83, 84, 85, 87 Anterior trunk, 66 Cervical 3 (C3) nerve, 98 attachments, 84 Anterior tympanic artery, 63 dorsal ramus, 99 defected upward, 84 Arnold ’ s nerve, 7, 8, 93 ventral ramus, 99 as modiolus component muscle, 81 Articular disc, 63, 65 Cervical nerve(s), dorsi rami, 91 Depressor labii inferioris muscle, 17, 22, Articular tubercle, 8, 9 Cervical plexus, 89, 102, 103 81, 82, 84 Ascending palatine artery, 53, 54, 68, 69, Cervicofacial division, 42, 43, 90, 101 Depressor septi muscle, 16, 42, 47, 48 70, 71 Choana, 15 attachments, 48 Ascending pharyngeal artery, 76, 78, 89 Chorda tympani, 3, 4, 5, 70, 71, 76, 77 Descending palatine artery, 52 meningeal branch, 7 with sphenoid bone spine removed, 76, Digastric groove (mastoid notch), 10, 100 Asterion, 10, 96, 100 77, 78 with digastric muscle posterior belly Atlas, transverse process, 67, 68, 70, 76, 96, Clinoidectomy, anterior, 6 detached, 90 97, 99, 101 Cochlea, opened, 4 Digastric muscle, 5, 6, 8, 77, 84, 95, 96, 97, Auditory tube. See Eustachian tube Columellar artery, 45, 47, 48, 87 98, 99, 100, 101 Auricular cartilages, lateral view, 93 Common carotid artery, 89 anterior belly, 71, 84, 87, 88 Auriculotemporal nerve, 22, 23, 32, 34, 40, Common facial nerve, 88 in facial reanimation, 56 44, 55, 58, 59, 61, 63, 65, 66, 68, 69, Common facial vein, 55, 85, 87, 90 posterior belly, 5, 43, 60, 85, 87, 88, 90, 71, 72, 77, 81, 86 Communicating branches, of facial nerve, 100 in midfacial region, 41, 44 detached from digastric groove, 90 B Condylar canal, 8, 10 Digastric ridge, 5, 77 Buccal artery, 65, 66, 86 Condylar head, 17, 18 Dorsal nasal artery, 26, 46 lingual branch, 63 Condylar neck, 17, 18 Dorsum sellae, 11 Buccal branches, of facial nerve, 39, 40, 41, Condylar process, 9, 44, 58 42, 43, 44 Contralateral artery, 92 E Buccal fat pad, 56, 57, 58, 60 Coronoid process, 9, 14, 17, 18, 58 Emissary foramen, 7 buccal extension, 59 Corrugator supercilii muscle, 16, 22, 25, 42, Emissary vein, 5 pterygoid extension, 59 45, 46, 81 Endolymphatic sac, 5 temporal (deep temporal) extension, 59 Cranial nerve IX, 76 Erb ’ s point, 102, 103

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Ethmoid bone, superior view, 13 marginal mandibular branch, 22, 43, 82, Frontomaxillary suture, 12, 16 Ethmoid sinus, 51, 52 84, 85, 101 Frontonasal suture, 12, 16 Eustachian tube, 4, 7, 8, 54, 71, 74 in masseteric region, 55, 57, 58, 59, 60 Frontotemporal region, 23, 24 bony part, 71 in mastoid region, 100 Frontozygomatic suture, 9, 12, 61 cartilaginous part, 7, 71 in midfacial region, 63, 65, 66, 67, 68, 69, opened, 78 70, 71, 74, 77, 78 G External acoustic meatus, 4, 8, 9, 10, 69, 74 refl ected posteriorly, 76 Galea aponeurotica, 21, 22, 23, 91 opened, 4 motor fi bers, 3 Galeal layer, 23 posterior edge, 100 pontine segment, 3 Ganglionic branches, 52 External carotid artery in posterior neck region, 95, 96, 97, 98, Geniculate ganglion, 4, 61 branches, 89 99 Geniohyoid muscle, 88 in lower facial region, 87 sensory nerve fi bers, 3 Gingiva in masseteric region, 58 temporal branches, 24, 32, 33, 34, 35, 36, maxillary, 50, 51 in midfacial region, 60, 63, 65, 66, 68, 69, 37, 38, 39, 40, 41, 42, 101, 103 palatal, 53 74, 76 trunk Glossopharyngeal nerve, 7, 8, 70, 72, 76, refl ected, 76 main, 90 78, 89 in temporal region, 34 posterior, 66 branches, 3, 7 External jugular vein, 39, 55, 81, 82, 102, structures adjacent to, 76–78 Great auricular artery, 97 103 upper branches, 40 Great auricular nerve, 22, 39, 43, 81, 93, External nasal artery, 48, 49 in upper neck region, 89 102, 103 External nasal nerve, 48, 49 venous valves, 45 Greater occipital nerve, 22, 82, 93, 94, 95, External nasal vein, 45, 48 vertical part, 5 96, 101, 102, 103 External oblique line, 17 zygomatic branches, 38, 39, 40, 41, 42, lateral branch, 91, 94 External occipital crest, 10 44, 101 medial branch, 91, 94 External occipital protuberance (inion), 10, zygomaticobuccal branches, 38, 39, 75, Greater palatine artery, 51, 53, 54, 72, 73, 91 83, 87 74 Facial nerve grafting, 103 Greater palatine canal, 53 F Facial region Greater palatine foramen, 15, 74 Face lower, 81–87, 90 Greater palatine nerve, 15, 51, 52, 54, 74 lateral oblique view, 81 with depressor anguli oris muscle Greater petrosal nerve, 3, 4, 75 lateral view, 21, 22 removed, 84 sensory innervation, 11 with lips removed, 87 H Facial artery, 21, 22 with opened mandibular canal, 85 Hyoid bone, 100 bifurcation, 46 with platysma muscle removed, 84 Hypoglossal canal, 8 c u t , 4 7 upper, overview, 21–22 Hypoglossal-facial nerve side-to-end inferior labial branch, 83 Facial reinnervation surgery, 39, 56 anastomosis, 5 in lower facial region, 81, 82, 83, 84, 85, hypoglossal muscle in, 76 Hypoglossal nerve, 68, 70, 76, 78, 89, 87, 90 masseteric nerve in, 58 97 in midfacial region, 39, 40, 68 Facial vein, 22, 39, 81 Hypoglossus muscle, 88 in oral fl oor, 88 in lower facial region, 82, 83, 84, 87 relationship to facial vein, 87 in lower neck region, 90 I superior labial branch, 83 in masseteric region, 58 Incisive artery, 53 in upper neck region, 89, 90 in midfacial region, 40, 41, 46, 48, 63 Incisive fossa, 16, 17 Facial bone, 12–18 in oral fl oor, 88 and canal, 15 Facial expression, 3 relationship to facial artery, 87 Incus, 77 Facial nerve, 4, 34, 35, 81 in upper neck region, 90 short process, 5 branch to digastric and stylohyoid Foramen ovale, 3, 7, 11, 15, 62 Inferior alveolar artery, 63, 66, 68, 69, 71, muscles, 90 Foramen rotundum, 6, 11, 13, 14, 52 74, 84, 85, 87, 88 buccal branches, 82, 101 Foramen spinosum, 7, 8 refl ected, 72 cervical branches, 81, 82, 101 Forehead, 23–26 Inferior alveolar nerve, 54, 63, 65, 66, 67, course of, 3 Frontal bone, 9 68, 69, 71, 73, 74, 84, 85, 87, 88 digastric branch, 100 nasal part, 16 mylohyoid branch, 85 exit site, 7 Frontal crest, 11 refl ected, 72 extratemporal segment, 3, 5 Frontalis muscle, 21, 22, 23, 24, 32, 33, 81 Inferior alveolar vein, 66, 68, 69, 71, 84, 85, intracranial (pontine or cisternal) frontal belly, 23 88 segment, 3 refl ected inferiorly, 25 Inferior joint space, midfacial region, 63 intraparotid branches, 42 separated from orbicularis oculi Inferior labial artery, 83, 84, 85, 87 intratemporal segment, 3 muscle, 24 Inferior nuchal line, 10, 98 landmark for branches of, 44 Frontal nerve, 26 Inferior oblique muscle, 75, 97, 98, 99 in lower facial region, 86 Frontal notch, 13, 16 Inferior ophthalmic vein, 75

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Inferior orbital fi ssure, 12, 13, 16, 64, 75 in posterior neck region, 95 Levator veli palatini muscle, 54, 70, 71, 72, lateral part, 73 in upper neck region, 89, 90 76 Inferior orbital fossa, 8 Internasal suture, 12 Lingual artery, 89 Inferior palpebral artery, 45 Intracranial region, 3–6 Lingual nerve, 54, 63, 65, 66, 68, 69, 70, 71, Inferior palpebral branch, 42 Intrajugular process, 7 73, 74, 76, 78, 85, 87, 88, 89 Inferior petrosal sinus, 7 Intraorbital nerve, 46 branch to medial pterygoid muscle, 72 Infrahyoid muscles, 100 Lingula, 18 Infraorbital artery, 41, 45, 47, 49, 50, J Longissimus capitis muscle, 5, 96 51, 52, 63, 64, 65, 66, 68, 69, 72, Jacobson ’ s nerve. See Glossopharyngeal refl ected inferiorly, 97 74, 75 nerve Infraorbital foramen, 15, 16 Joint capsule, 60 M Infraorbital nerve, 12, 14, 39, 41, 45, 47, Jugular bulb, 7 Malleus, 3 48, 49, 50, 51, 52, 64, 65, 66, 68, 69, Jugular foramen, 7, 8, 76, 78 handle, 77 72, 75, 87 Mandible, 87, 89, 100 inferior palpebral branch, 38, 41 L anterior view, 17 Infraorbital sulcus (groove), 12, 13 Lacrimal artery, 26 ascending ramus, 86 Infraorbital vein, 40, 45 Lacrimal fossa, 12, 13, 14 cut, 66, 67 Infratemporal crest, 8, 66, 68 Lacrimal gland, 3 muscles, 6 Infratemporal fossa, 8, 63–74, 86 Lacrimal nerve, 26 partially removed, 63, 88 with accessory ligaments of the Lambdoid suture, 10 posterolateral view, 18 temporomandibular ligament, 67 Laryngopharynx, sensory innervation, upper border of ramus, 58 anterior wall, 66 76 Mandibular angle, 82 with coronoid process removed, 63 Lateral cartilage, upper, 48 Mandibular canal, opened, 84, 85 with drilled mandibular fossa, 69 Lateral ligament, 55, 56, 57, 58, 60 Mandibular condyle, 10, 55, 58, 63, 85 with elevated mandibular nerve, 72 Lateral nasal artery, 39, 41, 45, 46, 47, 48, Mandibular foramen, 18, 85 with elevated tensor veli palatini 81, 83, 85, 87 Mandibular fossa, 8, 66, 68, 69 muscle, 70 alar arcade from, 45 opened, 4, 72, 77 with fractured pterygoid plate, 74 communication with external nasal Mandibular nerve, 4, 6, 11, 62, 69, 76 inferior boundary, 66 artery, 48 anterior trunk, 69 inferior orbital fi ssure in, 64 Lateral nasal wall, 48 motor division, 6 with lateral pterygoid muscle Lateral neck region, 102–103 posterior trunk, 69 removed, 65 posterior triangle posterolateral Mandibular notch, 9, 39, 58 with mandible removed, 68 view, 102 Marginal mandibular branch, of facial with mandibular condyle removed, 65 with sternocleidomastoid muscle nerve, 8, 22, 43, 84, 85, 101 with maxillary artery elevated, 73 retracted, 103 Masseteric artery, 56, 57, 86 with medial pterygoid muscle Lateral pterygoid muscle, 18, 52, 56, 75, Masseteric fascia, 39, 41, 81, 82 removed, 68 85, 87 opened, 82 medial wall, 66 lower head, 63, 64 Masseteric nerve, 54, 56, 57, 59, 60, 62, 66, osseous boundaries, 8 pterygoid head, 65 68, 72, 73, 86 with pterygoid plexus removed, 66 upper head, 62, 63, 64 intraoperative landmarks, 58 roof, 66 Lateral pterygoid plate, 8, 49, 65, 68, 69, refl ected, 63, 64, 71 with temporalis muscle removed, 63 71, 73 Masseteric region, 55–60 with tensor veli palatini muscle Lateral semicircular canal, 4, 5 with deep temporal fat pad removed, removed, 71 Lesser occipital nerve, 22, 82, 91, 93, 94, 60 Infratrochlear nerve, 26 95, 102, 103 with facial nerve branches removed, Inion (external occipital protuberance), 10, Lesser palatine artery, 53, 54 55 91 Lesser palatine foramen, 15, 74 with parotid gland removed, 55 Interfascial fat pad, 34 Lesser palatine nerve, 15, 52, 74 with zygomatic arch removed, 59 Intermaxillary suture, 14 Lesser petrosal nerve, 3, 72 Masseteric vein, 56 Internal acoustic meatus, roof, 3 Levator anguli oris muscle, 16, 22, 39, 40, Masseter muscle, 6, 18, 34, 44, 50, 51, 55, Internal carotid artery, 4, 6, 7, 61, 68, 72, 41, 42, 45, 46, 47, 48, 81, 83, 85 90 76, 89 as modiolus component muscle, 81 deep part, 57, 58 Internal carotid plexus, sympathetic Levator labii muscles, attachments, 47 for facial reanimation, 56 fi laments from, 11 Levator labii superioris alaeque nasi with fascia, 22 Internal jugular vein muscle, 45, 47, 48 middle part, 56, 57, 58 displaced laterally, 89 Levator labii superioris muscle, 16, 21, 22, refl ected, 57 in lateral neck region, 103 39, 40, 41, 42, 45, 46, 47, 81 refl ected, 86 in lower facial region, 87, 90 Levator palatini muscle, 78 downward, 58 in midfacial region, 7, 55, 67, 68, 69, 70, Levator palpebrae superioris muscle, 26 inferiorly, 86 71, 76 Levator scapulae muscle, 76, 96, 98 upward, 65

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Masseter muscle (cont.) Mental tubercle, 17 c u t , 7 6 superfi cial part, 58 Mental vein, 84, 85, 87 anastomosis in scalp, 92 attachment, 56, 57 Middle cranial fossa, 78 ascending branch, 91, 97 refl ected, 56 Middle deep temporal nerve, 62 descending branch, 91, 96, 97, 98, without fascia, 42 Middle ear, innervation, 8 99 Mastication, muscles of, 6, 56 Middle fossa, 3, 4 dissected from the groove, 100 Mastoid dura, 5 meningeal branch, 5, 7, 96, 100 after mastoidectomy, 5 superior view, 61 sternocleidomastoid branch, 90, 94 lateral view, 100 without bone, 62 transverse (cutaneous) branch, 91, Mastoid antrum, 9 Middle meningeal artery, 3, 4, 62, 63, 66, 96 Mastoidectomy, 101 68, 69, 71, 72, 76, 78 Occipital condyle, 7, 8, 9, 10 mastoid after, 5 groove for, 11 Occipital groove, 10 Mastoid emissary vein, 96, 100 orbital branch to lacrimal artery, 6 Occipitalis muscle, 21, 22, 91, 93 Mastoid foramen, 10, 96 Middle nasal concha, 14 bellies, 91 Mastoid notch (digastric groove), 10, 100 Middle superior alveolar nerve, 49, 52 Occipital region, 91–101 with digastric muscle posterior belly Middle temporal artery, 36, 55, 60, 61, Occipitofrontalis muscle, 23 detached, 90 100 Occipitomastoid suture, 10 Mastoid process, 5, 8, 9, 10, 84, 95, 96, 97, groove for, 9 Oculomotor nerve, 6, 11 99 Middle temporal vein, 35, 36, 37, 55, 57, Olfactory nerve, 13 Mastoid segment, 101 58, 59, 60 Ophthalmic artery, 26 Mastoid tip, 67, 69, 76 Midfacial region frontal nerve branch, 26 Maxilla deep structures, 61–78 lacrimal nerve branch, 6, 26 with anterior wall removed, 50 overview, 21–22 nasociliary nerve branch, 26 anteroinferior view, 14 superfi cial structures, 38–48 Ophthalmic nerve, 4, 6, 11 frontal process, 16 Mimetic muscles, 21, 22, 45 Ophthalmic veins, 11 with posterior and medial walls deep seated, 41 Optic canal, 11, 12, 13 opened, 51 modiolus, 22, 81, 83 opened, 6 Maxillary artery, 49, 52, 54, 63, 64, 65, 66, Minor salivary gland, 63 Optic nerve, 26 67, 68, 69, 70, 71, 72, 73, 74, 75, 78, 85 Modiolus, 22, 81, 83 with dura, 6 pterygoid segment, 86 Mylohyoid groove, 18 Optic strut, 13 pterygopalatine segment, 52 Mylohyoid line, 18 Oral commissure, 83 segments, 63 Mylohyoid muscle, 6, 84, 88 Oral fl oor, from the side, 88 Maxillary bone, 49 Mylohyoid nerve, 68, 70, 71, 84, 87, 89 Orbicularis oculi muscle, 16, 22, 33, palatine process, 15 38, 39, 40, 41, 42, 45, 46, 47, 48, Maxillary nerve, 4, 6, 11, 51 N 81, 83 infraorbital branch, 14 Nasal bone, 13, 14, 49 function, 83 zygomaticotemporal branch, 26 Nasalis muscle, 16, 42, 46, 48 as modiolus component muscle, 81 Maxillary ostium, 50, 51 alar part, 47 refl ected, 38, 55, 57 Maxillary region, 49–54 attachments, 48 upper, 32, 41 with mimetic muscles removed, 49 transverse part, 46, 47 Orbicularis oris muscle, 17, 22, 39, 41, 81, with veins removed, 52 Nasal septum, 14 82, 84 Maxillary sinus posterior edge, 54 upper, 39 orifi ce, 75 Nasociliary nerve, 26 Orbit, 12–16, 50, 51 posterior wall, 50 Nasolacrimal duct, 50, 51 anterior view, 12 Maxillary tuberosity, 49, 73 Nasolacrimal torus, 50, 51 anteromedial view, 13 Maxillary vein, 64, 65, 66, 67 Nasomaxillary suture, 16, 49 superior view, 26 Meckel ’ s cave, 4 Nasopalatine nerve, 15, 52, 53 Orbital fl oor, 50 Medial palpebral ligament, 16, 45 Nasopharynx, 74 Orbitalis (Müller ’ s) muscle, 64 Medial pterygoid muscle, 18, 56, 65, 66, Neck Orbital region, 23–26 69, 73, 85 posterior triangle, 102 Orbital septum, 45 superfi cial head, 63 upper region, 89–90 Oropharynx, sensory innervation, 76 Median palatine suture, 15 Nervus intermedius, 4, 5, 77 Otic ganglion, 3, 72 Meningo-orbital (lacrimal) foramen, 6, 12, Neurovascular bundle, 61 13 Nuchal ligament, attachment site, 10 P Mental artery, 84, 85, 87 Palatal region, 53–54 Mental foramen, 16, 17 O Palatine aponeurosis, 53, 54 Mentalis muscle, 17, 22, 81, 82, 84, 87 Occipital artery, 5, 10, 22, 43, 60, 67, 68, Palatine artery, ascending, 89 Mental nerve, 17, 84, 85, 87 69, 70, 71, 77, 90, 92, 93, 94, 95, 96, Palatine bone, 15 Mental protuberance, 16, 17 97, 98, 99, 101 Palatoglossus muscle, 70

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Parietal bone, 9 with longissimus capitis muscle refl ected Segmental muscle, 102 Parietal foramen, 92 inferiorly, 97 Sella turcica (pituitary fossa), 11 Parietomastoid suture, 10 with parotid gland superfi cial lobe Semicircular canals, 61, 77 Parotid duct, 22 removed, 101 Semispinalis capitis muscle, 94, 95, 97 in lower facial region, 85, 86, 87 with semispinalis muscle refl ected Sensation, facial nerve-based, 3 in masseteric region, 55, 60 inferiorly, 98 Sentinel vein, 34, 35, 37 cut and refl ected, 56, 57 with skin and galea removed, 91 Septal artery, 45, 46, 47, 48, 87 refl ected, 58 with splenius capitis muscle refl ected Sigmoid sinus, 5, 7, 77, 101 in midfacial region, 39, 40, 41, 42, 63 medially, 96 Skull relationship with buccinator with sternocleidomastoid muscle from above, 92 muscle, 85 refl ected laterally, 95 anterior view, 16 Parotid gland, 22 with trapezius muscle refl ected anteroinferior view, 14 buccal branch, 81 medially, 96 external and internal views, 7–11 deep lobe, 42 Posterior semicircular canal, 3, 4 lateral view, 9, 73 in lateral neck region, 103 Posterior superior alveolar artery, 52, 63, posterolateral view, 10 in midfacial region, 44 64, 65, 66, 69, 73, 75, 85 Skull base in posterior neck region, 93, 99 Posterior superior alveolar nerve, 52, 63, anterior (internal surface), 11 with substance removed, 44 64, 65, 66, 69, 73, 75, 85 external surface, 7 with superfi cial lobe removed, 42, 101 dental branch, 73 middle (internal surface), 11 tail, 82 gingival branch, 73 Soft palate, 68 in temporal region, 33, 34, 42 Posterior superior alveolar vein, 63, 64 Sphenofrontal suture, 12 Periauricular muscle, 21 Premasseteric artery, 39, 81, 82 Sphenoidal ridge, 11 Pericranial vein, 25 Prevertebral fascia, 102 Sphenoid bone, 9 Pericranium, 91 Procerus muscle, 16, 21, 42, 45, 46, 81 greater wing, 9, 11, 12 Petrotympanic (squamotympanic) Pterion, 9 lesser wing, 11 fi ssure, 5, 7, 69, 77 Pterygoid canal scaphoid fossa, 54 Pharyngeal plexus, 76, 89 artery of, 52 spine, 7 Phrenic muscle, 102 nerve of, 75 with spine removed, 69 Piriform (anterior nasal) aperture, 16 vein of, 75 Sphenoid sinus, 51, 52 Pituitary fossa (sella turcica), 11 Pterygoid fovea, 18 mucosa, 6 Platysma muscle, 17, 22, 81, 84, 87 Pterygoid hamulus, 8, 15, 53, 54 Sphenomandibular ligament, 66, 67 attachments, 84 Pterygoid muscle, 6 Sphenopalatine artery, 51, 52 Posterior alveolar canals, 73 Pterygoid plate, 52 Sphenopalatine foramen, 14 Posterior atlanto-occipital membrane, fractured, 74 Sphenopetrosal suture, 7 98 Pterygoid venous plexus, 45 Sphenozygomatic nerve, 12 Posterior auricular artery, 22, 69, 70, 81, deep component, 65 Spinal accessory nerve, 76 90, 91, 95, 100 Pterygomandibular raphe (ligament), 67, Splenius capitis muscle, 5, 22, 91, 93, 94, branches 68 95, 96, 97, 102, 103 anastomosis in scalp, 92 Pterygomaxillary fi ssure, 73, 74 Stapedius muscle, 5 auricular branch, 5, 43, 89, 94, 95, 96, Pterygopalatine fossa, 14, 52, 74, 75 Stapes incus, 3 100, 101 Pterygopalatine ganglion, 34, 51, 52, 74, 75 Sternocleidomastoid muscle, 5, 22, 39, 76, occipital branch, 43, 93, 94 81, 82, 91, 93, 94, 97, 102, 103 perforating artery from, 93 R anterior triangle, 94 Posterior auricular muscle, 22, 93 Rectus capitis lateralis muscle, 69, 76 cut and refl ected, 89 Posterior auricular nerve, 8, 22, 77, 91, 93, Rectus capitis posterior major muscle, 97, posterior triangle, 94 102, 103 98, 99 refl ected, 90, 95, 99 Posterior auricular vein, 22, 82, 93, 94, 95, Rectus capitis posterior minor muscle, 97, laterally, 95 103 98 medially, 96 Posterior circular artery, 68 Retromandibular vein, 34, 36, 42, 43, 44, retracted anteriorly, 103 Posterior deep temporal nerve, 62 55, 57, 58, 59, 60, 65, 85, 90 Styloglossus muscle, 68, 89 Posterior ethmoidal foramen, 13 anterior branch, 82, 90 Stylohyoid ligament, cut, 74 Posterior ethmoidal groove, 13 posterior branch, 82, 103 Stylohyoid muscle, 60, 90 Posterior ethmoidal nerve, 26 Retromolar fossa, 17, 86 Styloid process, 66, 69, 77 Posterior fossa dura, 5 Risorius muscle, 21 cut, 7, 8, 76, 78 Posterior lacrimal crest, 13 as modiolus component muscle, 81 Stylomandibular ligament, 67, 89 Posterior nasal spine, 15 Stylomastoid artery, 76, 78, 89 Posterior neck region, 91–101 S branch to digastric muscle, 69 with galea and occipitalis muscle Salpingopharyneus muscle, 71 foramen, 7 removed, 94 Scalp, from above, 92 Stylomastoid foramen, 7, 8, 100

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Stylopharyngeus muscle, 68, 70, 89 communicating branch, 24 Tensor tympani muscle, 4, 6, 61 Subclavian vein, 103 deep branches, 24, 25 Tensor veli alatini muscle, 6 Subgaleal fat pad, 32, 33, 37 superfi cial branches, 23, 24 Tensor veli palatini muscle, 54, 68, 69, 70, refl ected, 34 Supraorbital foramen, 13, 14, 16 75, 77 Sublingual artery, 88 Supraorbital nerve, 13, 23 branch to medial pterygoid muscle, 73 Sublingual fossa, 18 branches Tongue, innervation of, 3, 76 Sublingual gland, 3, 18 lateral (deep) branch, 23, 24, 25 Tonsillar artery, 68 ducts, 88 medial (superfi cial) branch, 23, 25 Tragal pointer (cartilage), 43 Submandibular fossa, 18 to skin (cut), 25 Transparent deep fat pad, 35 Submandibular ganglion, 5, 88 Supraorbital region, 25 Transparent superfi cial fat pad, 34 Submandibular gland, 3, 85, 87, 88, 90 medial view, 25 Transverse cervical nerve, 82, 102, 103 Submental artery, 68, 84, 85, 87, 88, 89 Supraorbital vein, 23, 25, 45, 81 Transverse facial artery, 22, 32, 34, 35, 38, Submental region, cutaneous Supratrochlear artery, 25, 26 39, 40, 41, 44, 55, 81 innervation, 71 branches Transverse facial nerve, 38, 42 Suboccipital muscles, 97 anastomosis in scalp, 92 Transverse palatine suture, 15 Suboccipital nerve. See Cervical 1 (C1) deep branch, 25 Transverse-sigmoid sinus junction, 100 nerve superfi cial branches, 23 Transverse supraorbital vein, 45 Suboccipital triangle, 98, 99 Supratrochlear nerve, 23, 25 Trapezius muscle, 91, 94, 95, 97 Subzygomatic fossa, 55 Supratrochlear vein, 25, 45, 81 refl ected medially, 96 Superfi cial (interfascial) fat pad, 34, 35, Trigeminal (gasserian or semilunar) 37 T ganglion, 3, 4, 6 Superfi cial musculoaponeurotic system Tegmen tympani, 3 Trigeminal nerve, 4, 6, 44 (SMAS), 21 Temporal bone, 9, 36 infraorbital branch, 12 Superfi cial temporal artery, 22, 32, 33, 34, tympanic part, 7 mandibular division, 6, 11 35, 36, 40, 42, 43, 44, 55, 57, 58, 59, Temporal branches, of facial nerve, 24, 32, maxillary division, 6, 11 60, 61, 63, 65, 66, 68, 69, 70, 71, 74, 33, 34, 35, 36, 37, 38, 40, 41, 42, 101, ophthalmic division, 6, 11 77, 81, 85 103 zygomatic branch, 12 frontal branch, 22, 23, 24, 33, 81 Temporal branches, of the facial Trochlear nerve, 6, 11, 26 parietal branch, 22, 81, 92 nerve, 38, 39, 40, 41, 42 Tuberculum sellae, 11 Superfi cial temporal fascia, 21 Temporal crest, 18 Tympanic cavity, 3 Superfi cial temporal vein, 22, 32, 33, 34, Temporal fascia, 24, 37, 100 Tympanomastoid fi ssure, 8 35, 36, 40, 42, 55, 57, 58, 59, 60, 81 deep layer, 35, 37 Tympanomastoid suture, 9, 70, 77 Superior alveolar nerves, 73 removed, 36 drop-off point, 8 Superior auricular artery, 32, 34 refl ected anteriorly, 34 Superior auricular muscle, 22, 32, 33, 81 superfi cial layer, 34, 35, 37 U Superior constrictor muscle, 68 refl ected upward, 34 Upper neck region, 89–90 Superior joint space, 63, 65 Temporal fossa, 8 Superior labial artery, 46, 48, 83, 85, 87 superior view, 61 V Superior laryngeal nerve, 89 Temporalis muscle, 18, 36, 37, 55, 56, 58, Vaginal process, 7, 8, 72, 78 Superior nuchal line, 91, 97, 98 60, 62, 94, 95 Vagus nerve, 7, 70, 76, 89, 102, 103 Superior oblique muscle, 26, 90, 97, 98, 99, for facial reanimation, 56 auricular (mastoid) branch, 7 100 fascia of. See Temporal fascia pharyngeal branch, 78 Superior ophthalmic vein, 26 refl ected, 61 Vertebral artery, 98, 99 Superior orbital fi ssure, 6, 11, 12, 13, 16 tendon, 58, 59, 75, 86 Vertebral venous plexus, 99 lateral edge, 6 Temporal muscle, 6 Vestibulocochlear nerve, 3, 4 Superior palpebral artery, 45 Temporal region, 32–37, 34, 36, 37 Vidian canal. See Pterygoid canal Superior petrosal sinus, 5 fat pads. See Deep fat pad; Subgaleal fat Vomer bone, 8, 15 Superior pharyngeal constrictor pad; Superfi cial fat pad muscle, 68, 70, 76 with temporoparietal fascia Z Superior rectus muscle, 26 refl ected, 34, 35 Zygomatic arch, 14, 34, 35, 36, 55, 56, 57, Superior temporal line, 9 Temporofacial division, 42, 43, 90, 58, 62 Superior thyroid artery, 89, 90 101 root, 61 Superior tympanic artery, 3, 4 Temporomandibular joint, 55, 63 Zygomatic bone, 9, 49 Supraclavicular nerve, 102, 103 Temporomandibular ligament, 9, 55 Zygomatic branches, of facial nerve, 38, 39, Supramastoid crest, 8, 9 accessory ligaments, 67 40, 41, 42, 44, 101 Suprameatal spine (Henle), 9 Temporoparietal fascia, 21, 23, 24, 32, 37, Zygomatic minor muscle, 81 Suprameatal triangle, 9 81 Zygomatic nerve, 12, 52 Supraorbital artery, 25, 26 refl ected, 34 branches, 12, 61 branches Tendinous arch, 91, 93 Zygomaticobuccal branches, of facial anastomosis in scalp, 92 Tensor tympani membrane, 4 nerve, 38, 39, 41, 44, 46, 75, 83, 87

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Zygomaticobuccal nerve, 38, 75 Zygomatico-orbital artery, 22, 23, 32, 40, 81 Zygomaticulotemporal nerve, 60 Zygomaticobuccal plexus, 42, 101 Zygomatico-orbital foramen, 12 Zygomaticus major muscle, 16, 21, 22, 34, Zygomaticofacial foramen, 9, 13, 49 Zygomaticotemporal foramen, 61 38, 39, 40, 41, 42, 44, 46, 55, 56, 57, Zygomaticofacial nerve, 12, 38, 49, 61, 63, Zygomaticotemporal nerve, 12, 26, 34, 35, 58, 81, 83, 85, 86 64 36, 55, 61 as modiolus component muscle, 81 Zygomaticomaxillary suture, 49 Zygomaticotemporal suture, 55 Zygomaticus minor muscle, 16, 41, 42, 46

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