Which two muscles can be felt on the side of the head and face when the teeth are clenched?

• A. Temporalis and masseter
• B. Digastric and Sternocleidomastoid
• C. Frontalis and Orbicularis oris
• D. Lateral pterygoid and Buccinator

Answer: (A)

When you clench your teeth, the jaw-closing muscles contract to bring the upper and lower teeth together. The two you can usually feel on the side of the head and face are the masseter and the temporalis. The masseter sits along the cheek, attaching from the cheekbone down to the lower jaw, and it elevates the mandible so you bite down; you can often feel a firm ridge or bulge just in front of the ear and along the jaw when you clench. The temporalis is a broad, fan-shaped muscle on the side of the skull above the ear; its fibers pull the mandible upward and help close the jaw, so you can sense tension at the temple region during strong clenching.

The other muscles listed aren’t typically palpated when teeth are clenched. The digastric and sternocleidomastoid are more involved in opening the jaw and moving the head or neck, not the strong closing action. The frontalis and orbicularis oris are facial expression muscles around the forehead and mouth and don’t contribute to the main clenching motion. The lateral pterygoid is involved in opening and protruding the jaw and is deep in the skull, while the buccinator forms part of the cheek wall to help keep food between teeth; neither is as readily felt on the side of the head during a clenched bite as the masseter and temporalis.