Which muscle is primarily responsible for jaw protrusion?

The muscle primarily responsible for jaw protrusion is the lateral pterygoid. This muscle plays a critical role in the movement of the mandible. It has two heads, and when these muscle fibers contract, they pull the head of the mandible forward and downward. This action is essential for functions such as biting and grinding food, as well as for certain speech movements.

In contrast, the medial pterygoid muscle primarily assists in the elevation of the mandible and contributes to lateral movements, but it does not significantly contribute to protrusion. The masseter is mainly involved in the elevation of the jaw and powerful biting down, while the temporalis muscle assists in elevating and retracting the mandible but is not primarily involved in protrusion. Understanding these specific roles helps clarify the movements of the jaw and the function of each muscle involved.