[ANAT] MUSCLES OF MASTICATION Flashcards
4 Muscles of mastication
temporalis
masseter
lateral pterygoid
medial pterygoid
which nerve generally supplies all 4 muscles?
mandibular
which embryological structure are all 4 muscles developed from?
mesoderm of 1st pharyngeal arch
all 4 muscles act on
TMJ
temporalis lies in
temporal fossa
masseter overlies
ramus of mandible
medial & lateral pterygoids are content of
infratemporal fossa
origin of temporalis
floor of temporal fossa & deep surface of temporal fascia
insertion of temporalis
all of coronoid process except lateral surface
extends on anterior surface of ramus down till last molar
origin of superficial head of masseter
anterior 2/3 of zygomatic arch
origin of deep head of masseter
posterior 1/3 of zygomatic arch
insertion of masseter
ramus (lateral surface)
origin of upper head lateral pterygoid
infratemporal crest & greater wing of sphenoid
origin of lower head of lateral pterygoid
lateral aspect of lateral pterygoid plate
insertion of lateral pterygoid
fovea
capsule of TMJ
articular disk of TMJ
origin of superficial head medial pterygoid
turberosity of maxilla
origin of deep head of medial pterygoid
medial aspect of lateral pterygoid plate
insertion of medial pterygoid
angle of mandible (medial aspect)
nerve supply of temporalis
2 deep temporal nerves
~from anterior division of mandibular nerve
nerve supply of masseter
masseteric branch
~from anterior division of mandibular nerve
nerve supply of lateral pterygoid
pterygoid branch
~from anterior division of mandibular nerve
nerve supply of medial pterygoid
branch from trunk of mandibular nerve
action of anterior vertical fibers of temporalis
elevation of mandible
action of posterior horizontal fibers of temporalis
retraction of mandible
action of deep vertical fibers of masseter
elevation of mandible
action of superficial oblique fibers of masseter
protraction of mandible
action of lateral pterygoid
depresses mandible–>opens mouth
protrudes mandible
side to side movement (for chewing)
action of medial pterygoid
elevates mandible
protrudes mandible
side to side for chewing
contraction of medial & lateral pterygoid causes
pushing of mandible to opposite side
all muscles are supplied by anterior division of mandible EXCEPT
medial pterygoid
all muscles cause protrusion of mandible EXCEPT
temporalis
All muscles cause elevation of mandible EXCEPT
lateral pterygoid
all muscles are inserted on inner side of ramus EXCEPT
masseter
only retractor of mandible
temporalis
only depressor of mandible
lateral pterygoid
upper border relations of pterygoid
deep temporal nerve
masseteric nerve
lower border relations of pterygoid
lingual nerve
inferior alveolar nerve+ vessels
relations of pterygoid between 2 heads of
buccal nerve
maxillary artery
superficial (lateral) relations of pterygoid (5)
1-ramus mandible
2-superficial head of medial pterygoid
3-tendon of temporalis
4-maxillary artery
5-pterygoid venous plexus
deep (medial) relations of pterygoid (8)
1-deep head of medial pterygoid
2-tensor palati
3-mandibular trunk
4-otic ganglia
5-chorda tympani
6-middle meningeal artery
7-maxillary artery
8-spheno-mandibular ligament