infratemporal fossa Flashcards
boundaries of temporal fossa
- superior: superior temporal line
- inferior: zygomatic arch
- anterior: zygomatic process of frontal bone and frontal process of zygomatic bone
- posterior: supramastoid crest
*Boundaries of the infratemporal fossa
- lateral: ramus of the mandible
- anterior: maxilla
- medial: lateral pterygoid plate
- roof: greater wing of sphenoid
- posterior: open
temporalis muscle
origin: temporal fossa, fascia and inbetween 2 temporal lines
insertion: coronoid process (apex, medial surface, anterior border until external oblique line of the mandible)
nerve supply: from deep temporal nerves; 1st branchial arch (from 1st pharyngeal arch V3)
action: elevation (by anterior fibers) and retraction (by posterior fibers) of the mandible
masseter
origin: inner surface and lower border of zygomatic arch (superficial–maxillary process; deep–whole length of zygomatic arch)
insertion: outer surface of ramus (superficial–lower part of ramus; deep–lateral surface of rams superior to superficial)
nerve supply: massetric nerve (branch from anterior division of V3 and passes mandibular notch
action: elevation and protraction of mandible
lateral pterygoid
origin: upper head–infratemporal surface and greater wing of sphenoid
lower head–lateral surface of lateral pterygoid
plate
Insertion: neck of mandible and articular disc of TMJ
Action: 1. pulls neck of mandible forward with articular disc to depress mandible and open mouth
2. acts with medial pterygoid of same side during movement of chewing (moving mandible to opposite side)
3. acts with medial pterygoid to protrude the mandible
medial pterygoid
Origin: superficial head–tuberosity of maxilla
deep head–medial surface of lateral pterygoid plate
Insertion: angle of the mandible (medial surface)
Nerve supply: main trunk of mandibular nerve (V3)
Action: elevates mandible, acting with lateral pterygoid during movement of chewing and protraction
pterygomandibular space
- located b/w medial pterygoid medially and mandibular ramus laterally
- contains inferior alveolar nerve (IAN) and artery (IAA) and lingual nerve (LN)
- communicates with parapharyngeal space posteriorly (infection here could be dangerous)
depression of mandible
lateral pterygoid digastric geniohyoid mylohyoid platysma
elevation
temporalis
masseter
medial pterygoid
protrusion
lateral and medial pterygoids of both sides
retraction
posterior fibers of temporalis
lateral chewing movement
lateral and medial pterygoids of both sides acting alternately
all muscles of mastication are protractors EXCEPT —-
Temporalis
all muscles of mastication are elevators EXCEPT —
lateral pterygoid
mandibular nerve
- arises from trigeminal ganglion in the middle cranial fossa
- immediately receives the motor root of the trigeminal nerve (sensory and motor)
- leaves cranium through the foramen ovale into the infratemporal fossa
- contains GSA (general somatic afferent) and SVE (spatial visceral efferent) fibers
- branches of CN V3 supply the four muscles of mastication but not the buccinator (supplied by facial nerve)
what’s the only muscular branch from posterior division of trigeminal?
nerve to mylohyoid
trunk of the mandibular nerve supplies?
medial pterygoid, tensor tympani, tensor palatini
anterior division of CN V supplies what muscles?
temporalis
lateral pterygoid
masseter
long buccal nerve supplies
only sensory division of anterior trigeminal
skin, mucous membrane, gum around buccinator
lingual nerve supplies
anterior 2/3 of tongue
general sensory?