Deep Face and Infratemporal Fossa Flashcards
Boundaries of the infratemporal fossa- lateral, anterior, medial, posterior, roof, inferior
Lateral- ramus of mandible Anterior- maxilla Medial- lateral pterygoid plate Roof- sphenoid greater wing Posterior- tympanic plate and mastoid and styloid process Inferior- angle of mandible
Muscles and arteries/veins in infratemporal fossa
Inferior portion of temporalis muscle
Lateral and medial pterygoid muscles
Maxillary artery
Pterygoid venous plexus
Nerves in infratemporal fossa
Inferior alveolar V3 Lingual V3 Buccal V3 Chorda tympani - CN VII Otic ganglion
Deep auricular artery
Branch of mandibular part of maxillary artery
Supplies external acoustic meatus, external TM and TMJ
Anterior tympanic artery
Branch of mandibular part of maxillary artery
Supplies internal TM
Inferior alveolar artery
Branch of mandibular maxillary
Enters mandibular foramen and supplies mandible, mandibular teeth, chin and mylohyoid muscle
gives off mylohyoid artery, later becomes mental artery
Middle meningeal artery
Branch of mandibular maxillary
Enters cranium via foramen spinosum and supplies dura mater of the lateral wall, trigeminal ganglion, facial nerve and geniculate ganglion, tympanic cavity and tensor tympani
Accessory meningeal artery
Branch of mandibular maxillary
Enters cranium via foramen ovale and supplies extracranial muscles of infratemporal fossa, otic ganglia and sphenoid bone
Maxillary artery in relation to lateral pterygoid
Can run lateral or medial to the lateral pterygoid muscle
Maxillary artery in relation to buccal, lingual, mandibular and inferior alveolar nerves
Runs lateral to inferior alveolar and medial to buccal nerve
Can run lateral or medial to lingual nerve
Runs medial to the mandibular nerve
Four muscles of mastication
Temporalis
Masseter
Lateral pterygoid
Medial pterygoid
Masseter muscle OINA
O- zygomatic bone and arch
I- mandibular angle/ramus
N- masseteric nerve- anterior division of CN V3
A- elevates mandible, assists in protraction, retraction and side to side motion
Temporalis OINA
O- temporal fascia and fossa I- Coronoid process of mandible N- deep temporal nerve (anterior division of CN V3) A- vertical fibers- elevate mandible horizontal fibers- retract mandible unilateral- lateral movement of mandible
Lateral pterygoid OINA
O- greater wing of sphenoid bone, lateral pterygoid plate
I- mandible and TMJ
N- Lateral pterygoid nerve (ant division of CN V3)
A- bilateral- protrudes mandible and opens mouth
unilateral- alternating actions, along with ipsilateral pterygoid, result in side to side movements necessary for grinding
Medial pterygoid OINA
O- maxilla and palatine bone, lateral pterygoid plate
I- pterygoid rugosity
N- medial pterygoid nerve (ant division of CN V3)
A- bilateral- elevation of mandible, also acts with lateral pterygoid to assist in protrusion
unilateral- acts with ipsilateral pterygoid to protrude mandible and produce medial movement toward opposite side. Alternating actions b/w right and left sides results in side to side chewing movement
Digastric muscle OINA
O- digastric fossa anteriorly, medial to mastoid posterior
I- body of hyoid bone via intermediate tendon
A- elevates hyoid during swallowing, assists in opening mandible
N- anterior belly- nerve to mylohyoid (from mandibular nerve of CN V)
posterior belly- facial nerve
Geniohyoid OINA
O- inferior mental spine of mandible
I- body of hyoid
A- draws hyoid forward during swallowing, assist in opening mandible
N- ventral ramus of C1
Mylohyoid OINA
O- mylohyoid line of mandible
I- body of hyoid bone by median tendon
A- tightens and elevates oral floor, draws hyoid forward during swallow, assists in opening mandible and moving it side to side
N- mylohyoid nerve from mandibular branch of CN V
Stylohyoid OINA
O- styloid process of temporal bone
I- body of the hyoid bone by split tendon
A- elevates hyoid bone during swallow, assists in opening mandible
I- facial nerve
Sternohyoid action innervation
Depresses/fixes hyoid bone
Depresses larynx and hyoid bone for phonating and the terminal phase of swallowing
N- ansa cervicalis of the cervical plexus C1-C3 and C4
Sternothyroid action innervation
A- draws the larynx and hyoid bone downward (fixes)
depresses the larynx and hyoid bone for phonating and terminal phase of swallowing
N- ansa cervicalis of the cervical plexus C1-3 and C4
Thyrohyoid action innervation
A- depresses and fixes hyoid, raises larynx during swallowing
N- ventral ramus of C1 and C4
Omohyoid OINA
O- superior border of scapula
I- body of hyoid
A- Depresses/fixes hyoid, draws larynx and hyoid bone downward for phonation and terminal phase of swallowing. Tenses the cervical fascia with its intermediate tendon and maintains patency of internal jugular vein
N- ansa cervicalis of cervical plexus C1-3 and C4
Elevation of mandible is primarily carried out by
Temporalis, masseter, medial pterygoids
Depression of mandible is primarily carried out by
Lateral pterygoids, suprahyoid and infrahyoid muscles
Protrusion of mandible primarily carried out by
Lateral pterygoids, masseter, medial pterygoids
Retrusion of mandible primarily carried out by
Temporalis, masseter
Lateral movements of mandible primarily carried out by
Ipsilateral temporalis and masseter + contralateral pterygoids
Ligaments of TMJ and their function
Lateral temporomandibular ligament
Stylomandibular ligament
Sphenomandibular
Latter 2 ligaments limit inferior excursion at TMJ
TMJ joint is innervated by
Mandibular branch of trigeminal- branches into auriculotemporal nerve, posterior deep temporal nerve and masseteric nerve
