Masseter Reflex

The masseter reflex, also known as jaw jerk reflex or mandibular tendon reflex, is the contraction of the muscles situated in the rear of the cheeks, which help in moving the jaws (masseter), and the fan-shaped muscles on each side of the skull, which are essential in mastication (temporalis muscle), when the lower jaw is tapped. This is checked to help assess spinal cord and brain status as an exaggerated masseter reflex may indicate a central nervous system concern.

For instance, a physician asks his patient to slightly open her mouth; he then taps her chin with a reflex hammer, this makes her jaw briskly move upward.