Which muscle is most involved in elevating the mandible and also contributes to protraction?

Which muscle is most involved in elevating the mandible and also contributes to protraction?

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

Answer: (D)

Elevation of the mandible is dominated by the masseter along with the temporalis and medial pterygoid. The masseter is the strongest elevator, pulling the mandible upward to close the mouth. It also has anterior fibers that help pull the mandible forward when biting, contributing to protrusion alongside other closing muscles. The lateral pterygoid is the primary protractor (opening and moving the jaw forward), but it does not elevate. The temporalis mainly elevates and retracts, and the medial pterygoid elevates with a lesser role in forward movement. So the muscle that best fits both actions—strongly elevating and aiding forward movement—is the masseter.

Elevation of the mandible is dominated by the masseter along with the temporalis and medial pterygoid. The masseter is the strongest elevator, pulling the mandible upward to close the mouth. It also has anterior fibers that help pull the mandible forward when biting, contributing to protrusion alongside other closing muscles. The lateral pterygoid is the primary protractor (opening and moving the jaw forward), but it does not elevate. The temporalis mainly elevates and retracts, and the medial pterygoid elevates with a lesser role in forward movement. So the muscle that best fits both actions—strongly elevating and aiding forward movement—is the masseter.