Infratemporal p regions g Infratemporal fossa: fossa space behind the maxilla, maxilla b l below & deep d to t the th zygomatic ti arch h 1 Infratemporal fossa Ant.: posterior aspect of the maxilla Med.: lateral pterygoid plate Post.: tympanic plate, plate, mastoid and styloid processes Lat: ramus of the mandible 2 Infratemporal fossa Sup : infratemporal surface of the greater wing of the sphenoid bone Sup.: Inf.: where the medial pterygoid m. attaches 3 Contents of the infratemporal fossa temporalis m. Lat. pterygoid m. Med pterygoid m Med. m. 4 Contents of the infratemporal fossa temporalis m. 5 Contents of the infratemporal fossa Lat. pterygoid m. Med. pterygoid m. 6 Contents of the infratemporal fossa Lat. pterygoid m. Med. pterygoid m. 7 Contents of the infratemporal fossa Med pterygoid m Med. m. 8 Contents of the infratemporal fossa Pterygoid venous plexus: located between the temporalis & the lat. pterygoid m., m and partly between two pterygoid m. m Connect with a) cavernous sinus, b) vein of obit, c) pharyngeal plexus, d) facial v., e) maxillary v. 9 Maxillary a. Deep p auricular a.: ascend in the parotid gland posterior to the TMJ Ant. tympanic a.: enter the tympanic cavity Inf. alveolar a.: descend with the inf. alveolar n. to the mandibular foramen Middle meningeal a.: a : between the sphenomandibular lig lig. and lat. lat pterygoid m m. m., enter the foramen spinosum Accessory meningeal a.: enter the foramen ovale 10 Maxillary a. Masseteric a.: passes laterally through mandibular notch Deep temproal a.: passes between the temporalis m. and pericranium p Pterygoid br.: to lat. and med. pterygoid m. Buccal a a.:: courses between the heads of the lat. pterygoid m.., in 11 company with buccal n. Maxillary a. Middle meningeal a.: between the sphenomandibular h dib l lig. li and d lat. l t pterygoid m., m. enter the foramen spinosum Inf. alveolar a.: descend with the inf. alveolar n. to the mandibular foramen Masseteric a.: passes laterally through mandibular notch Buccal a.: courses between the heads of the lat. pterygoid m. m., in company with buccal n. 12 Mandibular division of trigeminal n. Mandibular division of trigeminal nerve via the foramen ovale Meningeal br.: passes back via the foramen spinosum in company with ith middle iddl menigeal i l a. Medial pterygoid n.: via the otic ganglion to supply medial pterygoid m. m Lateral pterygoid n.: enter the deep surface of lat. pterygoid m. 13 Mandibular division of trigeminal n. Deep ttemporall n.: superior D i to t lat. l t pterygoid t id m., m. enter t th the deep d surface f off temporalis m. Masseteric n.: passes through the mandibular notch to supply masseteric m. and TM joint Buccal n.: passes between the two heads of the lateral pterygoid m. 14 Mandibular division of trigeminal n. Auriculotemporal n n.:: arises by two roots which encircle the middle meningeal a a. and form a single trunk, processed between the neck of the mandible and the sphenomandibular ligament I f i alveolar Inferior l l n: company with ith lingual li l n. , via i mandibular dib l foramen f Lingual n.: courses between the medial pterygoid m.. and the body of the mandible 15 Mandibular division of trigeminal n. Inferior alveolar n: company with lingual n. , via mandibular foramen Mylohyoid n.: arises near the mandibular foramen from the inf. alveolar n., to supply mylohyoid m. and ant. belly of digastric m. Lingual n.: courses between the medial pterygoid m. and the body of the mandible Chorda tympanic n.: belong to facial n. , jjoins with lingual g n.,, to synapse y p the submandibular ganglion to supply the submandibular and sublingular glands. Otic ganglion: is located just below the foramen ovale 16 Mandibular division of trigeminal n. Chorda tympani B Buccal l n. Auriculotemporal n. Inferior alveolar n. Lingual n. Mylohyoid n. Auriculotemporal n.: arises by two roots which encircle the middle meningeal a. and form a single trunk, processed between the neck of the mandible and the sphenomandibular ligament Buccal n.: passes between the two heads of the lateral pterygoid m. 17 18 Temporomandibular joint (TMJ) Articular tubercle Head of condyloid process Mandibular of mandible fossa The TMJ is a synovial joint between (i) the articular tubercle, the mandibular fossa of the temporal bone above, and (ii) the head of the condyloid process of the mandible below 19 Temporomandibular joint (TMJ) articular capsule: from rim of mandibular fossa and articular tubercle to neck of condyloid process lateral (temporomandibular) lig. articular disk lower surface is concave and upper surface is concavoconvex a thickened part of the capsule, extends from the zygomatic arch to the neck of the mandible 20 Temporomandibular joint (TMJ) sphenomandibular ligament from the spine of the sphenoid bone to the lingula of the mandible stylomandibular ligament from the apex of the styloid process to the posterior border of the ramus of the mandible near 21 its angle Temporomandibular joint (TMJ) lateral (temporomandibular) lig. a thickened part of the capsule, extends from the zygomatic arch to the neck of the mandible stylomandibular ligament from the apex of the styloid process to the posterior border of the ramus of the mandible near its angle sphenomandibular ligament from the spine of the sphenoid bone to the lingula of the mandible 22 Temporomandibular joint (TMJ) blood supply pp y — superficial p temporal p branch of the external carotid a., masseteric a. innervation — branches of the auriculotemporal and masseteric nerves. 23 Muscles of mastication temporalis: from temporal line to coronoid process and ant. border of the ramus of the mandible masseter: from inferior border of zygomatic arch to lateral surface of the ramus of the mandible and coronoid process lateral pterygoid: from greater wing of the sphenoid bone and lateral pterygoid plate to neck of the mandible medial pterygoid: from tuberosity of the maxilla and the medial surface of the lateral pterygoid plate to the angle and ramus of the mandible 24 Actions of temporomandibular joint 25 Actions of temporomandibular joint 26 Infrafemporal fossae Contents of the infratemporal fossa: part of the temporalis, lateral and medial pterygoid muscles, l maxillary ill artery, t pterygoid t id venous plexus, l and d th the mandibular and chorda tympani nerves Maxillary artery: Middle meningeal a., inferior alveolar a., masseteric a., buccal a. Mandibular division: Masseteric n., buccal n., auriculotemporal n., lingual n., inferior alveolar n., mylohyoid n. Otic ganglion: Lesser petrosal n., n auriculotemporal n n., parotid gland 27 Temporomandiblular joint (TMJ) The TMJ is a synovial joint between (i) the articular tubercle, the mandibular fossa of the temporal bone above, and (ii) the head of the condyloid process of the mandible below Ligament: Articular capsule, lateral (temporomandibular) ligament, articular disk, disk sphenomandibular ligament, ligament stylomandibular ligament Muscles of mastication : T Temporalis, li masseter, t l t l pterygoid, lateral t id medial di l pterygoid t id 28 Infratemporal Regions and TM Joint Dr. Lue, Grossanatomy Infrafemporal fossae Infratemporal fossa: is the irregularly shaped space behind the maxilla, below and deep to the zygomatic arch 1) bounded by: Lat.: ramus of the mandible; Med.: lateral pterygoid plate; Ant.: post. aspect of the maxilla; Post.: tympanic plate, mastoid and styloid processes; Sup.: infratemporal surface of the greater wing of the sphenoid bone; Inf.: where the medial pterygoid m. attaches 2) the contents of the infratemporal fossa: part of the temporalis, lateral and medial pterygoid muscles, maxillary artery, pterygoid venous plexus, and the mandibular and chorda tympani nerves Mm of mastication Pterygoid venous plexus— located partly between the temporalis and the lateral pterygoid, and partly between the two pterygoid muscles - connects with a) cavernous sinus; b) veins of the orbit; c) pharyngeal plexus of veins; d) facial v.; e) maxillary v. Maxillary artery The first part of the maxillary artery passes through bony canals deep auricular a.: ascend in the parotid gland posterior to the TMJ external auditory meatus anterior tympanic a.: enter the tympanic cavity middle meningeal a.: between the sphenomandibular lig. and lat. pterygoid m., enter the foramen spinosum accessory meningeal a.: enter the foramen ovale inferior alveolar a.: descend with the inferior alveolar n. to the mandibular foramen The second part supplies muscles of mastication and buccinator muscles masseteric a.: passes laterally through the mandibular notch deep temporal aa. (anterior and posterior): passes between the temporalis m. and pericranium pterygoid branches. lateral and medial pterygoid muscles buccal a.: courses between the heads of the lateral pterygoid muscle and in 1 company with the buccal nerve Mandibular division of trigeminal nerve via the foramen ovale A. Undivided trunk (a) meningeal br.: passes back via the foramen spinosum in company with middle meningeal a. (b) medial pterygoid n. via otic ganglion to supply medial pterygoid muscle — also provides the nerve to the tensor veli palatini muscle and the nerve to the tensor tympani m. B. Anterior division (a) masseteric n.: passes through the mandibular notch to supply masseteric m. and TM joint (b) lateral pterygoid n.: enter the deep surface of that muscle (c) deep temporal n. (anterior & posterior): superior to lateral pterygoid m., enter the deep surface of temporalis m. (d) buccal n.: passes between the two heads of the lateral pterygoid m., to innervate skin of the cheek and mucous membrane of the mouth C Posterior division auriculotemporal n.: arises by two roots which encircle the middle meningeal a. and form a single trunk, proceeds between the neck of the mandible and the sphenomandibular ligament, supplies parts of the auricle, external acoustic meatus, tympanic membrane and skin in temporal region — carries postganglionic parasympathetic fibers (belonging to the glossopharyngeal nerve) from otic ganglion to parotid gland lingual n.: course between the medial pterygoid m. and the body of mandible, GSA to anterior 2/3 of tongue and contiguous gums; joined by chorda tympani n., which consists of: i) carries preganglionic parasympathetic fibers (belonging to facial n.) to synapse in the submandibular ganglion to innervate the submandibular and sublingual glands; and ii) SVA for anterior 2/3 of the tongue inferior alveolar n.: company with the lingual n. — via mandibular foramen mandibular canal a) incisive n.; b) inf. dental plexus; and c) mental n. (mental foramen) — mylohyoid n.: arises near the mandibular foramen from the inferior alveolar 2 nerve innervate mylohyoid m. and anterior belly of digastric m. Otic ganglion: is located just below the foramen ovale, below passes though it: a) nerve to medial pterygoid, tensor tympani and tensor veli palatini m. (no synapse) b) postganglionic sympathetic from plexus on middle meningeal a. (no synapse) c) preganglionic parasympathetic (lesser petrosal n.)from IX (synapse), then by auriculotemporal n. to innervate parotid gland Temporomandiblular joint (TMJ) The TMJ is a synovial joint between (i) the articular tubercle, the mandibular fossa of the temporal bone above, and (ii) the head of the condyloid process of the mandible below. Ligaments 1) articular capsule: from rim of mandibular fossa and articular tubercle to neck of condylar process 2) lateral (temporomandibular) ligament — a thickened part of the capsule, extends from the zygomatic arch to the neck of the mandible 3) articular disk: lower surface is concave and upper surface is concavoconvex 4) sphenomandibular ligament: from the spine of the sphenoid bone to the lingula of the mandible 5) stylomandibular ligament : from the apex of the styloid process to the posterior border of the ramus of the mandible near its angle. Innervation and blood supply blood supply— superficial temporal branch of the external carotid a., masseteric a. innervation — branches of the auriculotemporal and masseteric nerves. Muscles of mastication 1) temporalis: from temporal line to coronoid process and ant. border of the ramus of the mandible 2) masseter: from inferior border of zygomatic arch to lateral surface of the ramus of the mandible and coronoid process 3) lateral pterygoid: from greater wing of the sphenoid bone (sup. head) and lat. surface of lateral pterygoid plate (inf. head) to neck of the mandible 4) medial pterygoid: from tuberosity of the maxilla (superficial head) and the 3 medial surface of the lateral pterygoid plate (deep head) to the angle and ramus of the mandible The chief factors responsible for these movements may be summarized as follows: Action Muscles provided depression lateral pterygoid, digastric, gravity elevation temporalis, masseter, medial pterygoid protrusion lateral and medial pterygoids, masseter retraction temporalis (post. fibers) lateral movement temporalis and masseter (ipsilateral), medial and lateral pterygoids (contralateral) 4
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