Myofascial pain-dysfunction syndrome: a psychobiological perspective.

Myofascial pain-dysfunction (MPD) syndrome is a muscle-contraction headache-like pain of the face. In the past this has also been called temporomandibular joint syndrome. This syndrome is thought to be, in part, a stress-related pain. This paper discusses and evaluates the following topics: (1) patient characteristics, (2) etiological hypotheses, (3) experimental models of the syndrome, (4) psychological characteristics of the patients, (5) psychophysiological characteristics of the patients, and (6) relaxation therapies. Future research is also discussed.