Temporal Region The temporal region includes the temporal and infratemporal fossae, superior and inferior to the zygomatic arch, respectively Temporal fossa In which the temporal muscle (L. temporalis) is located Is bounded : à Posteriorly and superiorly by the temporal lines à Anteriorly by the frontal and zygomatic bones à Laterally by the zygomatic arch à Inferiorly by the infratemporal crest à Floor by frontal, parietal, temporal, and greater wing of the sphenoid (bone of pterion) à Roof by the temporal fascia Temporal fossa Temporal fascia covers the temporal muscle, attaching superiorly to the superior temporal line. Inferiorly, the fascia splits into two layers, which attach to the lateral and medial surfaces of the zygomatic arch. The temporal fascia also tethers the zygomatic arch superiorly. When the powerful masseter muscle, which is attached to the inferior border of the arch, contracts and exerts a strong downward pull on the arch, the temporal fascia provides resistance. Temporal fossa Contents: 1. Temporalis ms arises from the bony floor and the overlying temporal fascia 2. Superficial temporal nerve and vessels 3. Deep temporal nerve and vessels 4. auriculotemporal nerve Infratemporal fossa is an irregularly shaped space deep and inferior to the zygomatic arch, deep to the ramus of the mandible and posterior to the maxilla. It communicates with the temporal fossa through the interval between (deep to) the zygomatic arch and (superficial to) the cranial bones. Infratemporal fossa- Boundaries Lateral = ramus of mandible Medial = lateral pterygoid plate Anterior = posterior aspect of maxilla Posterior = tympanic plate and the mastoid & styloid process of temporal bone. Superior = infratemporal surface of the greater wing of sphenoid bone. Inferior = medial pterygoid muscle attaches to the mandible near the angle Infratemporal fossa, contents. Inferior part of the temporal muscle Lateral and Medial Pterygoid muscle Maxillary artery (2nd part) and its branches Pterygoid venous plexus Mandibular nerve and its branches : à inferior alveolar à lingual à buccal Otic Ganglion chorda tympani nerve , from facial nerve Maxillary artery The maxillary artery is the larger of the two terminal branches of the external carotid artery It arises posterior to the neck of the mandible and is divided into three parts based on its relation to the lateral pterygoid muscle. Course of 1st partBranches Distribution Proximal Deep auricular Supplies external acoustic meatus, external (posterior) to artery tympanic membrane, and temporomandibular joint lateral pterygoid Anterior tympanic Supplies internal aspect of tympanic muscle; runs artery membrane horizontally, deep Middle meningeal Enters cranial cavity via foramen spinosum to (medial) to neck artery supply periosteum, bone, red bone marrow, of condylar dura mater of lateral wall and calvaria of process of neurocranium, trigeminal ganglion, facial nerve and geniculate ganglion, tympanic mandible and cavity, and tensor tympani muscle lateral to stylomandibular Accessory Enters cranial cavity via foramen ovale; its ligament meningeal artery distribution is mainly extracranial to muscles of infratemporal fossa, sphenoid bone, mandibular nerve, and otic ganglion Inferior alveolar Descends to enter mandibular canal of artery mandible via mandibular foramen; supplies mandible, mandibular teeth, chin, mylohyoid Course fo 2nd part Branches Distribution Adjacent (superficial Masseteric artery Traverses mandibular notch, or deep) to lateral supplying temporomandibular pterygoid muscle; joint and masseter ascends obliquely anterosuperiorly, Deep temporal Anterior and posterior arteries medial to temporal arteries ascend between temporal muscle muscle and bone of temporal fossa, supplying mainly muscle Pterygoid branches Irregular in number and origin; supply pterygoid muscle Buccal artery Runs anteroinferiorly with buccal nerve to supply buccal fat-pad, buccinator, and buccal oral mucosa Infratemporal fossa, contents The pterygoid venous plexus: à is located partly between the temporal and the pterygoid muscles. à It is the venous equivalent of most of the maxillary artery ,that is, most of the veins that accompany the branches of the maxillary artery drain into this plexus. à Anastomoses anteriorly with the facial vein via the deep facial vein and superiorly with the cavernous sinus via emissary veins. à The extensive nature and volume of this plexus is difficult to appreciate in the cadaver Infratemporal fossa, contents The mandibular nerve descends through the foramen ovale into the infratemporal fossa and divides into sensory and motor branches. The branches of CN V3 are the auriculotemporal, inferior alveolar, lingual, and buccal nerves. Branches of the CN V3 also supply the four muscles of mastication but not the buccinator, which is supplied by the facial nerve. Infratemporal fossa, contents The otic ganglion (parasympathetic): à Is located in the infratemporal fossa, just inferior to the foramen ovale, medial to CN V3 and posterior to the medial pterygoid muscle. à Presynaptic parasympathetic fibers, derived mainly from the glossopharyngeal nerve, synapse in the otic ganglion. à Postsynaptic parasympathetic fibers, which are secretory to the parotid gland, pass from the otic ganglion to this gland through the auriculotemporal nerve. Infratemporal fossa, contents The auriculotemporal nerve: à Encircles the middle meningeal artery à Divides into numerous branches, the largest of which passes posteriorly, medial to the neck of the mandible, and supplies sensory fibers to the auricle and temporal region. à Also sends articular fibers to the TMJ and parasympathetic secretomotor fibers to the parotid gland. The inferior alveolar nerve: à Enters the mandibular foramen and passes through the mandibular canal, forming the inferior dental plexus, which sends branches to all mandibular teeth on its side. à Another branch of the plexus, the mental nerve, passes through the mental foramen and supplies the skin and mucous membrane of the lower lip, the skin of the chin, and the vestibular gingiva of the mandibular incisor teeth. Infratemporal fossa, contents The lingual nerve: à lies anterior to the inferior alveolar nerve. à sensory to the anterior two thirds of the tongue, the floor of the mouth, and the lingual gingivae. à Enters the mouth between the medial pterygoid muscle and the ramus of the mandible and passes anteriorly under cover of the oral mucosa, just inferior to the 3rd molar tooth. The chorda tympani nerve: à branch of CN VII carrying taste fibers from the anterior two thirds of the tongue, joins the lingual nerve in the infratemporal fossa . à Also carries secretomotor fibers for the submandibular and sublingual salivary glands. Infratemporal fossa, clinical Mandibular Nerve Block à An anesthetic agent is injected near the mandibular nerve where it enters the infratemporal fossa. In the extraoral approach, the needle passes through the mandibular notch of the ramus of the mandible into the infratemporal fossa. The injection usually anesthetizes the auriculotemporal, inferior alveolar, lingual, and buccal branches of CN V3. Inferior Alveolar Nerve Block à Anesthetizes the inferior alveolar nerve, a branch of CN V3. The site of the anesthetic injection is around the mandibular foramen, the opening into the mandibular canal on the medial aspect of the ramus of the mandible. This canal gives passage to the inferior alveolar nerve, artery, and vein. When this nerve block is successful, all mandibular teeth are anesthetized to the median plane. The skin and mucous membrane of the lower lip, the labial alveolar mucosa and gingivae, and the skin of the chin are also anesthetized because they are supplied by the mental nerve, a branch of the inferior alveolar nerve. Pterygopalatine fossa A small pyramidal space inferior to the apex of the Orbit. Lies between the pterygoid process of the sphenoid posteriorly and the posterior aspect of the maxilla anteriorly. Is a major distributing center for branches of the maxillary nerve and the pterygopalatine (third) part of the maxillary artery. Boundaries: à Medial wall = vertical plate of palatine bone à Roof (incomplete)= greater wing of the sphenoid bone à Floor = pyramidal process of the palatine bone à Superior larger end opens into the inferior orbital fissure à Inferior end is closed except the palatine foramina Pterygopalatine fossa It is located between, and has communications with, the infratemporal fossa, nasal cavity, orbit, middle cranial fossa, pharyngeal vault, maxillary sinus, and oral cavity (palate) It communicates with the following: à Laterally thru the pterygomaxillary fissure= infratemporal fossa à Medially thru sphenopalatine foramen = nasal cavity à Anterosuperiorly thru inferior orbital fissure = Orbit. à Posterosuperiorly thru foramen rotundum and pterygoid canal = Middle cranial fossa. The fossa has been exposed through the floor of the orbit and maxillary sinus. The foramen rotundum, pterygoid canal, and pharyngeal canal are openings in the posterior wall of the pterygopalatine fossa. Pterygopalatine fossa , contents Contents: 1. Terminal 3rd or the pterygopalatine part of the maxillary artery and branches. +accompaning veins 2. Maxillary nerve ( enters thru the foramen rotundum) and branches: à Zygomatic Nerves Zygomaticofacial + zygomaticotemporal nerves à Pterygopalatine nerves 3. Nerve of the pterygoid canal. 4. Pterygopalatine ganglion. 5. Surrounding fatty matrix Third