Which head of the lateral pterygoid muscle assists in opening the mandible?

The inferior head of the lateral pterygoid muscle is responsible for assisting in the opening of the mandible. This muscle plays a critical role in the movement of the jaw, particularly during the actions of depression and protrusion.

When the inferior head contracts, it pulls the head of the mandible forward and down, facilitating the opening of the mouth. This action is essential during activities such as chewing, speaking, and other functions involving jaw movement. The superior head, in contrast, primarily stabilizes the disc of the temporomandibular joint (TMJ) and is less involved in the process of depressing the mandible.

Therefore, recognizing the specific functionalities of the heads of the lateral pterygoid muscle is key to understanding its role in jaw movement, particularly in relation to TMJ dynamics.