Which muscle elevates the mandible and assists protrusion?

• A. Masseter
• B. Temporalis
• C. Medial pterygoid
• D. Lateral pterygoid

Answer: (C)

Elevating the mandible while helping push it forward fits the action of the medial pterygoid. This deep muscle sits on the inner surface of the mandible and, when it contracts, pulls the jaw upward toward the maxilla. Its pull is directed toward the angle of the mandible, so it also contributes to forward movement of the jaw (protrusion) when working with the other muscles of mastication. The lateral pterygoid is the primary mover for protrusion and opening, while the temporalis mainly elevates with the posterior fibers retruding, and the masseter elevates as well (often aiding in protrusion but not as specifically tied to forward movement). The medial pterygoid uniquely combines elevation with a forward pull, making it the best fit for elevating the mandible and assisting protrusion.