The strongest muscle based on its weight is the masseter. This facial muscle plays major role in chewing foods, clenching teeth and closing the jaw. When all the muscles of the jaw are working together, the masseter can close the teeth with a force as great as 55 pounds (25 kilograms) on the incisors or 200 pounds (90.7 kilograms) on the molars. The muscle is formed as a parallelogram and connected to the mandible (lower jawbone) and the cheekbone.

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A note from anatomy:

Three other muscles assist the masseter during chewing: the temporalis (temporal muscle), medial pterygoid (internal pterygoid muscle), and lateral pterygoid (external pterygoid).

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