MUSCLES OF MASTICATION Flashcards
muscles of mastication
- it provides movement for the temporomandibular joint.
- all four muscles develop from the mesoderm of the embryonic first pharyngeal arch
- all supplied by the maxillary artery
temporalis
PA= floor of temporal fossa and deep surface of temporal fascia
DA= narrow attachment to tip and medial surface of the coronoid process and the anterior border of the ramus of the mandible
IN= anterior trunk of the mandibular nerve(CN V3) and deep temporal branches
MA= elevates mandibule
closing jaws
more horizontal fibers are first degree retractors of the mandible
masseter
PA= 1. inferior border and medial surface of maxillary process of the zygomatic bone and the zygomatic arch
DA= angle and lateral surface of the ramus of the mandible
IN= 1. anterior trunk of mandibular nerve(CN V3) via masseteric nerve
MA= 1. elevates mandible 2. close jaws, 3. superficial fibers make a limited contribution to the protrusion of the mandible
lateral pterygoid
PA= 1. infra-temporal surface and crest of the greater wing of sphenoid 2. lateral surface of lateral pterygoid plate
DA= 1. superior head attaches to the joint capsule and an articular disc of TMJ
2. inferior head attaches to pterygoid fovea on the anteromedial aspect of the neck of the condyloid process of mandible
IN= anterior trunk of mandibular nerve(CN V3) vis lateral pterygoid nerve
MA= 1. acts bilaterally to protracts mandible and depress chin
- acts unilaterally to swing jaw toward the contralateral side
- unilateral contraction produces larger chewing movements
medial pterygoid
PA= 1. MEDIAL SURFACE OF LATERAL PTERYGOID PLATE AND PYRAMIDAL PROCESS OF PALATINE BONE
2. and tuberosity of maxilla
DA= medial surface of ramus of mandible, inferior to mandibular foramen
IN= anterior trunk pf mandibular nerve(CN V3) via medial pterygoid nerve
MA= 1. acts synergistically with masseter to elevate the mandible
- contributes to the protrusion
- unilateral activity produces smaller grinding movements
