Which muscles close the jaw?

• A. Masseter and temporalis.
• B. Digastric and lateral pterygoid.
• C. Zygomaticus and masseter.
• D. Frontalis and temporalis.

Answer: (A)

Closing the jaw relies on muscles that lift the lower jaw up toward the upper jaw. The two primary jaw elevators are the masseter and the temporalis. The masseter runs from the cheekbone area to the angle and side of the mandible, providing strong biting force by elevating the mandible. The temporalis sits over the temporal bone and attaches to the coronoid process of the mandible, also elevating the jaw and able to assist with retraction. Together they are the main muscles that bring the teeth together during biting or chewing. Another muscle, the medial pterygoid, also helps close the jaw, but it isn’t paired with the temporalis in the given option. The remaining muscles listed either open the jaw (such as the digastric and, to some extent, the lateral pterygoid, which helps with opening and protrusion) or perform facial expressions or movements unrelated to jaw closure.