The lateral pterygoid muscle on each side is one of the muscles which act upon the temporomandibular joint. It arises from two heads:
- superior head: infratemporal surface of the greater wing of the sphenoid bone
- inferior head: lateral surface of lateral pterygoid plate
It passes superiorly, laterally and posteriorly to insert at two sites:
- internal surface of neck of mandible
- intra-articular cartilage of temporomandibular joint
Lateral pterygoid is innervated by the branches from the anterior division of the mandibular nerve (CN V).
In isolation, the lateral ptergoid muscle acts to move the mandible medially. In combination, both muscles act to depress and protract the mandible. Also, they pull the joint cartilage anteriorly when the mouth opens.