Temporal muscle this portion results in retrusion of the mandible. When lower dentures are fitted, they should not extend into the retromolar fossa to prevent trauma of the mucosa due to the contraction of the temporalis muscle. The temporalis is likely to be involved in jaw pain and headaches. Bruxism, the habitual grinding of teeth typically while sleeping, and clenching of the jaw while stressed can lead to overwork of the temporalis and results in pain. A myotendinous rupture of the temporalis can occur during a seizure due to extreme clenching of the jaw. During a seizure the contralateral temporalis muscle can
Bruxism sleep, the voluntary muscles are inactive due to physiologic motor paralysis, and the jaw is usually open. Some bruxism activity is rhythmic with bite force pulses of tenths of a second (like chewing), and some have longer bite force pulses of 1 to 30 seconds (clenching). Some individuals clench without significant lateral movements. Bruxism can also be regarded as a disorder of repetitive, unconscious contraction of muscles. This typically involves the masseter muscle and the anterior portion of the temporalis (the large outer muscles that clench), and the lateral pterygoids, relatively small bilateral muscles that act together to perform sideways