MUSCLES OF MASTICATION (quick and dirty version) Flashcards
origin of masseter
zygomatic arch
insertion of masseter
- lateral surface of ramus
- angle of the mandible
action of masseter
- elevates the mandible
- provides the force for chewing
- superficial head aids in chewing
origin of temporalis
temporal fossa and lateral surface of skull
insertion of temporalis
coronoid process and anterior border of ascending ramus
action of temporalis
retrusion
origin of inferior lateral pterygoid
outer surface of the lateral pterygoid plate
insertion of inferior lateral pterygoid
neck of condyle
action of inferior lateral pterygoid
bilateral contraction: protrusion & depression
unilateral contraction: mediotrusive movement
origin of superior lateral pterygoid
infratemporal surface of the greater sphenoid wing
insertion of superior lateral pterygoid
disk, capsule, and neck of condyle
action of superior lateral pterygoid
*inactive during mandibular opening
- active with elevator muscles (chewing or clenching)
origin of medial pterygoid
pterygoid fossa
insertion of medial pterygoid
medial surface of the mandibular angle
action of medial pterygoid
- elevation
- protrusion
- unilateral contraction: mediotrusion
what forms the muscular sling?
masseter and medial pterygoid
what is the function of the suprahyoids?
elevate the hyoid bone and depress the mandible when the hyoid bone is fixed
contraction of what muscles causes depression of the mandible?
- inferior lateral pterygoid
- digastric
contraction of what muscles causes elevation of the mandible?
- masseter
- medial pterygoid
- temporalis
(some sources also include superior lateral pterygoid)
contraction of what muscles cause lateral movement?
inferior lateral pterygoid (opposite of direction of movement)
contraction of what muscles causes protrusion?
- inferior lateral pterygoid
- masseter
- medial pterygoid
contraction of what muscles causes retrusion?
temporalis
