Anatomy of the Face and Neck 2 Peter M. Prendergast 2.1 Introduction Following a description of the hard tissue foundation, the soft tissues of the face will be described, from Safe and effective cosmetic surgical practice relies on a superfi cial to deep, in the following order: clear knowledge and understanding of facial anatomy. 1. Superfi cial fat compartments Techniques evolve and improve as the complex, lay- 2. Superfi cial musculoaponeurotic system (SMAS) ered architecture and soft tissue compartments of the 3. Retaining ligaments face are discovered and delineated through imaging, 4. Mimetic muscles staining techniques, and dissections both intraopera- 5. Deep plane, including the deep fat compartments tively and in the research laboratory on cadavers [ 1 ] . To create a more youthful, natural-looking form, the sur- geon endeavors to reverse some of the changes that 2.2 Facial Skeleton occur due to aging. These include volumetric changes in soft tissue compartments, gravitational changes, and Facial appearance is to a large extent determined by the attenuation of ligaments. Whether the plan of reju- the convexities and concavities of the underlying facial venation includes rhytidectomy, platysmaplasty, autol- bones (Fig. 2.1 ). The “high” cheekbones and strong ogous fat transfer, implants, or endoscopic techniques, chin associated with attractiveness are attributable to a sound knowledge of facial and neck anatomy will the convexities and projection provided by the zygo- increase the likelihood of success and reduce the inci- matic bone and mental protuberance of the mandible, dence of undesirable results or complications. respectively (Fig. 2.2 ). The facial skeleton consists of This chapter describes the anatomy of the face in the frontal bone superiorly, the bones of the midface, layers or planes, with some important structures or and the mandible inferiorly. The midface is bounded regions described separately, including the facial nerve, superiorly by the zygomaticofrontal suture lines, infe- sensory nerves, and facial arteries. The superfi cial riorly by the maxillary teeth, and posteriorly by layers and topography of the neck are also described. the sphenoethmoid junction and the pterygoid plates. The facial skeleton forms the hard tissue of the face and The bones of the midface include the maxillae, the provides important structural support and projection zygomatic bones, palatine bones, nasal bones, zygo- for the overlying soft tissues, as well as transmitting matic processes of the temporal bones, lacrimal bones, nerves through foramina and providing attachments for ethmoid bones, and turbinates. The facial skeleton several mimetic muscles and muscles of mastication. contains four apertures: the two orbital apertures, the nasal aperture, and the oral aperture. The supraorbital foramen (or notch) and the frontal notch are found at the superior border of each orbit and transmit the supraorbital and supratrochlear nerves, respectively. P. M. Prendergast Venus Medical , Dublin , Ireland The maxillary bones contribute to the nasal aperture, e-mail: [email protected] bridge of the nose, maxillary teeth, fl oor of the orbits, M.A. Shiffman and A. Di Giuseppe (eds.), Cosmetic Surgery, 29 DOI 10.1007/978-3-642-21837-8_2, © Springer-Verlag Berlin Heidelberg 2012 30 P.M. Prendergast Fig. 2.1 Frontal view of the facial skeleton and cheekbones. The infraorbital foramen lies in the The mandible forms the lower part of the face. In maxilla below the inferior orbital rim and transmits the midline, the mental protuberance gives anterior the infraorbital nerve. The zygomaticofacial foramen projection to the overlying soft tissues. Laterally, the transmits the zygomaticofacial nerve inferolateral to ramus of the mandible underlies the masseter muscle the junction of the inferior and lateral orbital rim. and continues superiorly to articulate with the cranium 2 Anatomy of the Face and Neck 31 Fig. 2.2 Convexities of the facial skeleton Temporal process of zygomatic bone Zygomatic bone Zygomatic process of maxilla Mental protruberance of mandible through the coronoid process and condylar process from one another by delicate fascial tissue and septae of the mandible. The mental nerve emerges from that converge where adjacent compartments meet the mental foramen on the body of the mandible in to form retaining ligaments. The superfi cial fat com- line vertically with the infraorbital and supraorbital partments of the face comprise the following: the naso- nerves. labial fat compartment; the medial, middle, and lateral As well as providing structural support, projection, temporal-cheek “malar” fat pads; the central, middle, and protection of sensory organs such as the eyes, and lateral temporal-cheek pads in the forehead; and the facial skeleton provides areas of attachment for the superior, inferior, and lateral orbital fat pads the muscles of facial expression and the muscles of (Fig. 2.4). Nasolabial fat lies medial to the cheek fat mastication (Fig. 2.3 ). pad compartments and contributes to the overhang of the nasolabial fold. The orbicularis retaining ligament below the inferior orbital rim represents the superior 2.3 Superfi cial Fat Compartments border of the nasolabial fat compartment and the medial cheek compartment (Fig. 2.5 ). The middle The pioneering work of Rohrich and Pessa [ 2 ] , using cheek fat compartment lies between the medial and staining techniques and cadaver dissections, has lateral temporal-cheek fat compartments and is revealed a number of distinct superfi cial fat compart- bounded superiorly by a band of fascia termed the ments in the face. These compartments are separated superior cheek septum. The borders of the middle 32 P.M. Prendergast Fig. 2.3 Areas of muscle Procerus attachments to the facial skeleton Corrugator supercilii Orbicularis oculi Temporalis Upper orbital part Palpebral part Levator labii superioris Lower orbital part alaeque nasi Levator labii superioris Zygomaticus major Zygomaticus minor Masseter Levator anguli oris Nasalis: transverse part Depressor septi Nasalis: alar part Temporalis Buccinator Platysma Masseter Depressor anguli oris Mentalis Depressor labii inferioris cheek compartment, the inferior, and the lateral orbital adheres to the depressor anguli oris muscle and is fat pad compartments converge to form a tougher band bounded medially by the depressor labii and inferiorly of tissue called the zygomatic ligament [3 ] . The con- by bands of the platysma muscle. Premental and pre- densation of connective tissue at the borders of the platysmal fat abut the jowl fat compartment. medial and middle fat compartments correlates with The compartmentalized anatomy of the superfi cial the masseteric ligaments in the same location [4 ] . The subcutaneous fat of the face has implications in the lateral temporal-cheek fat pads span the entire face aging process. Volume loss appears to occur at from the forehead to the cervical area. Its anterior different rates in different compartments, leading to boundary, the lateral cheek septum, is encountered irregularities in facial contour and loss of the seam- during facelift procedures with medial dissection from less, smooth transitions between the convexities and the preauricular incision. In the forehead, its upper and concavities of the face associated with youthfulness lower boundaries are identifi able as the superior and and beauty. inferior temporal septa. Medial to the lateral temporal- cheek fat compartment in the forehead, the middle temporal fat pad is bounded inferiorly by the orbicu- 2.4 Superfi cial Musculoaponeurotic laris retaining ligament and medially by the central System forehead fat compartment. Above and below the eyes, the superior and inferior orbital fat compartments lie In 1976, Mitz and Peyronie [ 5 ] published their descrip- within the perimeter of the orbicularis retaining liga- tion of a fi brofatty superfi cial facial fascia they called ment. These periorbital fat pads are separated from the superfi cial musculoaponeurotic system (SMAS). one another medially and laterally by the medial and This system or network of collagen fi bers, elastic lateral canthi, respectively. The lateral orbital fat fi bers, and fat cells connects the mimetic muscles to compartment is the third orbital fat pad and is bounded the overlying dermis and plays an important func- superiorly by the inferior temporal septum and inferi- tional role in facial expression. The SMAS is central to orly by the superior cheek septum. The zygomati- most current facelift techniques where it is usually dis- cus major muscle attaches, through fi brous septae, to sected, mobilized, and redraped. In simple terms, the overlying superfi cial fat compartments along its length. SMAS can be considered as a sheet of tissue that In the lower third of the face, the jowl fat compartment extends from the neck (platysma) into the face (SMAS 2 Anatomy of the Face and Neck 33 Fig. 2.4 The superfi cial fat Lateral Temporal-Cheek Middle forehead compartments of the face (forehead) Central Lateral orbital Medial Superior orbital Middle Inferior orbital Nasolabial Lateral temporal-cheek Jowl Pre-platysma fat proper), temporal area (superfi cial temporal fascia), mouth to the overlying skin and has an important role and medially beyond the temporal crest into the fore- in transmitting complex movements during animation. head (galea aponeurotica). However, the precise anat- Over the parotid gland, the SMAS is relatively thick. omy of the SMAS, regional variations, and even the Further medially,