Which muscles of mastication are visible around the angle of the mandible when the patient clenches their jaw?

The masseter muscle is the primary muscle of mastication that is prominently visible around the angle of the mandible when a patient clenches their jaw. This muscle is crucial for the process of chewing, as it elevates the mandible, allowing for the powerful closure of the jaw against food.

When the jaw is clenched, the masseter muscle becomes tense and creates a noticeable bulge along the outer surface of the mandible, particularly at the angle. This visibility is due to its strategic location and robust structure, designed for generating the force required for chewing.

In contrast, the lateral and medial pterygoid muscles, although involved in the movement and stabilization of the mandible, are situated deep within the jaw and are not visible externally. The temporalis muscle, while it plays a significant role in raising the jaw, is positioned high on the side of the skull and primarily contributes to the closure of the jaw from a different angle, rather than at the angle of the mandible itself. Thus, the masseter stands out as the key muscle involved when the jaw is clenched and is easily identifiable at that location.