The temporalis muscle is located at the temples of the skull. It originates on the temporal lines of the parietal bone of the skull. It inserts on the coronoid process of the mandible. It functions bilaterally to close the jaw, and unilaterally to deviate the mandible to the same side. When trigger points develop in this muscle they often cause headaches into and above the eye and temple as well as hypersensitivity of the teeth.