Trismus

Trismus is a condition in which one of the jaw muscles tightens or spasms, holding the mouth shut. A person with trismus has problems talking, eating, and brushing his or her teeth.

Trismus can result from injury, problems with the joint, surgery, radiation treatment, or sometimes problems with clenching or tightening the jaw.

Treatment depends on the cause of the problem but often includes oral devices and exercises.