Hello again! It’s Matt from Kenhub, and in this tutorial, we will discuss the function of the lateral pterygoid muscle.
The pterygoid muscles or wing muscles are two jaw muscles located on the inner surface of the mandible. One is called the medial pterygoid, and the other is the lateral pterygoid, which you see highlighted in green and will be our topic of discussion.
The lateral pterygoid muscle has two heads, which lie almost horizontally to each other. The small superior head runs from the infratemporal crest of the sphenoid to the articular disc of the temporomandibular joint. The much larger inferior head courses from the pterygoid process of sphenoid to the condylar process of mandible.
Due to its anatomy, palpation of the lateral pterygoid is quite difficult. This muscle is innervated by a nerve with the same name, the lateral pterygoid nerve, which branches out from the mandibular nerve.
The pterygoid muscles are muscles of mastication and serve the movement of the temporomandibular joint, seen here highlighted in green.
The lateral pterygoid differs from the other three muscles of mastication as it is the only one among then that can open the jaw.
Once the lateral pterygoid opens the jaw, the movement is, then, continued with the help of the suprahyoid muscles. The bilateral activation of the lateral pterygoid also causes protrusion whereas the unilateral contraction moves the mandible laterally, which causes laterotrusion and, this way, supports chewing.