Masseter and temporalis muscles
The masseter runs from the temporal bone (that forms part of the sides and base of the skull) to the lower jaw (the mandible). It lifts the lower jaw, to close the mouth. The masseter is the strongest muscle in your body.
The temporalis begins on two bones of the skull, at the front (the frontal) and at the side and base (the temporal). It runs to the top of the lower jaw (the mandible). Like the masseter, the temporalis helps close the mouth.