Psychophysiological assessment in chronic orofacial pain.

Psychophysiological models of chronic pain conditions have emerged in recent years due, in part, to the inadequacy of structural models to explain the etiology, maintenance, exacerbation, and/or remediation of these conditions. Psychophysiological theories of temporomandibular disorders (TMD) and related research evidence are reviewed. It is concluded that a number of methodological problems in previous psychophysiological studies of TMD preclude reaching firm conclusions that psychological stress causes masticatory hypermuscle arousal in TMD patients. Recommendations and guidelines for future psychophysiological research in TMD are presented.