M1 - Anatomy Parotid Gland, Temporomandibular Joint and Infratemporal Fossa Jeff Dupree Sanger 9-057 jldupree@vcu.edu Parotid gland: wraps around the mandible positioned between the mandible and the sphenoid bone extends posteriorly to the external acoustical meatus and mastoid process Temporomandibular joint: formed by the articulation of the condyle of the mandible and the mandibular fossa of the temporal bone Infratemporal fossa: concave space behind the maxilla; below the sphenoid and temporal and medial to the zygomatic arch 1 2 -parotid wraps around ramus of mandible Parotid Gland and Facial Nerve Parotid Gland -largest of three salivary glands -CN VII pierces parotid -divides into deep and superficial lobes -5 branches distal to parotid -2 branches proximal to parotid 3 -not all of CN VII exits stylomastoid foramen 4 Parotid Gland Innervation 5 6
Parotid Gland Innervation Submandibular Gland Innervation Parasympathetic Innervation (motor secretion) Inferior salivatory nucleus CN IX Tympanic branch passes through tympanic plexus Lesser petrosal Otic ganglion (post syn.) Auriculotemporal nerve Parotid Gland 7 8 Submandibular Gland Innervation Lacrimal Gland Innervation Parasympathetic Innervation (secretomotor) Superior salivatory nucleus Nervus Intermedius (VII) Chorda tympani (petrotympanic fissure) submandibular ganglion (post syn.) Lingual n. (V) Submandibular Gland Sublingual Gland 9 10 Lacrimal Gland Innervation Parasympathetic innervation (secretomotor) Superior salivatory nucleus nervus intermedius passes through geniculate ganglion greater petrosal n. Temporomandibular Joint nerve of pterygoid canal (Vidian nerve) pterygopalatine gang. (post syn) communicating branch lacrimal n. lacrimal gland 11 12
Bones of the Temporomandibular Joint Bones of the Temporomandibular Joint 13 14 Mandible 15 16 Temporomandibular Joint Ligaments Movements of the TMJ Joint Capsule Temporomandibular Stylomandibular Sphenomandibular 17 18
Structures Vulnerable to TMJ Trauma Muscles of Mastication -temporalis -masseter -medial pterygoid -lateral pterygoid 19 20 Muscles of Mastication Insertion of Temporalis Muscle Temporalis: O: temporal, parietal frontal I: coronoid process A: closes, retracts Masseter O: zygomatic arch I: angle of mandible A: closes 21 22 Muscles of Mastication Muscles of Mastication Insertion Medial pterygoid: O: sphenoid and maxilla I: angle of mandible A: closes Lateral pterygoid: O: sphenoid I: condylar process, articular disc A: grinds, protracts 23 24
25 26 Actions of Muscles of Mastication Temporalis: closes, retracts Masseter: closes Medial pterygoid: closes Lateral pterygoid: grinds, protracts Summary of TMJ Bones: mandible: condylar process temporal: mandibular fossa articular tubercle sphenoid: spine Ligaments (stabilization) fibrous joint capsule temporomandibular (lateral stability) sphenomandibular (swinging hinge) stylomandibular All muscles of mastication are innervated by branches of the mandibular division of the trigeminal cranial nerve (CN V 3 ) 27 Muscles: temporalis: closes masseter: closes medial pterygoid: closes lateral pterygoid: grinds, opens 28 Boundaries of the Infratemporal Fossa Med.: sphenoid, temporal Infratemporal Fossa Lat.: temporal, mandible, zygomatic Sup.: sphenoid Inf.: mandible 29 30
Med.: sphenoid, temporal Ant: maxilla Post.: temporal Boundaries of the Infratemporal Fossa Muscles of the Infratemporal Fossa Muscles of Mastication Temporalis Medial pterygoid Lateral pterygoid EXCEPTION: masseter 31 32 Arteries of the Infratemporal Fossa Arteries of the Infratemporal Fossa Maxillary artery: -posterior border of ramus of mandible -3 parts: mandibular, muscular, pterygopalatine -1 st and 2 nd parts are in infratemporal fossa -3 rd part is in pterygopalatine fossa 33 34 Entrance of Maxillary Artery into Infratemporal Fossa First Division of the Maxillary Artery -mandibular division -between neck of mandible and sphenomandibular ligament -5 branches: deep auricular anterior tympanic middle meningeal accessory meningeal 35 inferior alveolar mylohyoid, mental 36
Mandibular Division of Maxillary Artery Mandibular Division of Maxillary Artery Deep auricular: TMJ, lat. Tympanic membrane, external acoustical meat. Anterior tympanic: med. Tympanic membrane, petrotympanic fissure Middle meningeal: passes thru 2 roots of auriculotemporal n, f. spinosum Ant. Tympanic Middle meningeal Accessory meningeal Accessory meningeal: meninges, Otic ganglion of CN V, f. ovale, mandibular division of CN V Inferior alveolar: mylohyoid, mandibular canal, terminal branch mental a 37 38 Crescent of foramina Mandibular Division of Maxillary Artery So R O S So superior orbital: CNs 3, 4 V 1, 6, ophthalmic veins R-- rotundum: V 2, O-- ovale: V 3, accessory menigeal a. S-- spinosum: middle menigeal a Petrotympanic fissure: formed by the junction of the petrous and tympanic portions of the temporal bone -anterior tympanic artery *****-chorda tympani***** 39 40 Mandibular Division of Maxillary Artery Inferior alveolar: mylohyoid mental 41 42
Muscular Division of Maxillary Artery Muscular Division of Maxillary Artery -4 branches -named for the muscles of mastication (primarily) Masseteric Deep temporals Pterygoid branches Buccal 43 44 Veins of the Infratemporal Fossa Superficial temporal + maxillary (pterygoid plexus) = retromandibular Retromandibular divides- anterior division posterior division Anterior division + facial and lingual aa = internal jugular Posterior division + posterior auricular = external jugular 45 46 Nerves of the Infratemporal Fossa Nerves of the Mandibular Division of CN V Mandibular Division (V 3 ) Trigeminal Nerve CN V -Trunk -Anterior division (primarily motor) -Posterior division (primarily sensory) 4 branches of trunk: meningeal n. n. to medial pterygoid n. to tensor veli palatini n. tensor tympani 47 48
Nerves of the Mandibular Division Anterior Division 5 branches: -n. to masseter -anterior deep temporal -posterior deep temporal -n. to lateral pterygoid Nerves of the Mandibular Division of CN V n. to masseter ant. deep temporal post. deep temporal n. to lateral pterygoid buccal n. -buccal n. All motor EXCEPT buccal n. 49 50 Nerves of the Mandibular Division of CN V Nerves of the Mandibular Division of CN V Posterior Division 3 branches: -auriculotemporal n. -lingual n. -inferior alveolar n. Primarily sensory -inferior alveolar gives branches to ant. belly of digastric and mylohyoid 51 52 Nerves of the Mandibular Division of CN V 53 54
Innervation for Taste of Anterior 2/3 of Tongue Innervation of Submandibular Gland geniculate ganglion chorda tympani joins (piggy backs) lingual nerve taste to anterior 2/3 of tongue 55 56 Summary of Tongue and Submandibular Gland General sensation to ant.2/3 of tongue lingual n. Taste to anterior 2/3 of tongue chorda tympani Submandibular gland: preganglionic parasympathetic (chorda tympani) joins the lingual n. submandibular ganglion post-ganglionic parasympathetic to submandibular gland 57