Infratemporal Fossa Flashcards
what is the door between the middle cranial fossa and the infratemporal fossa?
foramen ovale
what foramen does the opthalmic branch of the trigeminal nerve pass through?
superior orbital fissure
what foramen does the maxillary branch of the trigeminal nerve pass through?
foramen rotundum
what foramen does the mandibular branch of the trigeminal nerve pass through?
foramen ovale
what supplies sensory to the forehead, upper eyelids, and bridge of nose?
V1
what supplies sensory info to above the cheekbones, upper lip, lower eyelids and side of nose?
V2
what supplies sensory info to the lower lip and strip of skin around the jaw line and before the ear?
V3
what is the ceiling of the maxillary sinus?
the floor of the orbit
what is the floor of the orbit?
the ceiling of the maxillary sinus
where does V1 extend into?
orbit
where does V2 extend?
pterygopalatine fossa
where does V3 extend?
infratemporal fossa
anterior wall of infratemporal fossa
infratemporal surface of the maxilla
ceiling of the infratemporal fossa
laterally: temporalis muscle
medially: greater wing of sphenoid
medial wall of infratemporal fossa
lateral pterygoid plate
lateral wall of the infratemporal fossa?
ramus of mandible
posterior wall and floor of infratemporal fossa?
both open
what is the opening between infratemporal fossa and pterygopalatine fossa?
pterygomaxillary fissure on medial wall
contents of the infratemporal fossa
- temporalis muscle
- medial pterygoid muscle
- lateral pterygoid mucle
- V3 mandibular nerve branches
- maxillary artery and its branches
- sphenomandibular ligament
sensory branches of the mandibular nerve
- auriculotemporal
- buccal
- inferior alveolar
- lingual
motor branches of the mandibular nerve
- nerve to temporalis
- nerve to lateral pterygoid
- nerve to medial pterygoid
- nerve to mylohyoid
describe the route of the auriculotemporal nerve
splits around the middle meningeal artery, runs with superficial temporal artery laterally toward the parotid and ear, then makes a 90degree turn to run up in front of the ear
what does the nerve to mylohoid innervate?
comes from inferior alveolar – mylohyoid muscle and the anterior belly of the digastric
describe the path of the inferior alveolar nerve
once splits from lingual nerve, dives into the mandible to the lower teeth (sensory). continues along the mandible to exit through the mental foramen, becoming the mental nerve to do sensory to the chin.
what does the auriculotemporal nerve innervate?
skin around the ear, 2 branches course around the middle meningeal artery and then runs with superficial temporal arteries
what does the lingual nerve innervate?
anterior 2/3 tongue general sensory, joined by chorda tympani which does taste to anterior 2/3 and secretomotor to sublingual and submandibular glands.
what does the inferior alveolar nerve innervate?
enters mandibular foramen on the inner surface of the mandible. in mandibular canal = sensory for mandibular teeth. at mental foramen, becomes mental nerve and provides sensory innervation to chin
what does the mylohyoid branch of the inferior alvelolar nerve innervate?
passes along inner surface of the mandible below the mylohyoid line/groove, provides motor fibers to mylohyoid muscle and anterior belly of the digastric
what ligament runs through the middle of the infratemporal fossa?
sphenomandibular ligament
muscles of mastication \
- temporalis
- masseter
- medial pterygoid
- lateral pterygoid
insertion of temporalis muscle
coronoid process, down along anterior surface of mandible, and anterior border of ramus as far anteriorly as 3rd molar.
origin of temporalis muscle
temporal fossa
action of temporalis
primarily elevator of mandible, but can also retract mandible d/t posterior and middle portions of the muscle
which is the only muscle of mastication that lies OUTSIDE of the infratemporal fossa?
masseter
origin of masseter
zygomatic arch
insertion of masseter
lateral surface of mandible
action of masseter
POWERFUL elevator of jaw, deeper fibers retract mandible
origin of medial pterygoid
pyramidal process of palatine bone in pterygoid fossa and the medial surface of the lateral pterygoid plate
where is the bulk of the medial pterygoid muscle?
behind the lateral pterygoid muscle
insertion of the medial pterygoid
is directed inferiorly, posteriorly, and laterally to insert on medial surface of the ramus of mandible (kind of diagonal when looking from side)
action of medial pterygoid
“an internal masseter” – elevator of mandible
what muscles form the “mandibular sling”?
masseter and medial pterygoid muscles
where does the superior (smaller) head of the lateral pterygoid originate?
infratemporal region of the greater wing of the sphenoid bone as far laterally as the infratemporal crest
where does the inferior (larger) head of the lateral pterygoid muscle originate?
lateral surface of the lateral pterygoid plate
insertion of the superior head of lateral pterygoid muscle
fibers travel posteriorly and laterally (almost horizontally) from the intratemporal crest to the articular capsule of the temporomandibular joint, the anterior border of the articular disk, and superior part of the mandibular neck
direction of the inferior lateral pterygoid muscle
directed posteriorly, laterally and slightly superiorly to the mandible
action of the lateral pterygoid
bilaterally: protrudes mandible
unilaterally: slides jaw from side to side
why is the lateral pterygoid unique?
superior head: insertion into articular disk and capsule stabilizes the mandibular condyle
inferior head: pulls mandible and disk forward and down, opening the jaw
what would indicate damage to V3 nerve?
if patient protrudes jaw and it deviates to one side, the V3 nerve is damaged on the side that the jaw deviates toward. V3 innervates medial and lateral pterygoid muscles.
