SENSITIVITY OF PATIENTS WITH PAINFUL TEMPOROMANDIBULAR DISORDERS TO EXPERIMENTALLY EVOKED PAIN

Temporomandibular disorders (TMD) represent a group of chronic painful conditions involving the muscles of mastication and the temporomandib ular joint. We determined whether patients with painful TMD are more s ensitive to noxious stimuli than age-matched control subjects. Fifty-t wo TMD patients (16 with muscle pain and 36 with combined muscle and j oint pain) and 23 age-matched and gender-matched volunteers participat ed. Forearm thermal pain threshold and tolerance values were determine d. A submaximal effort tourniquet procedure was used to evoke ischemic muscle pain. Relative to control subjects, TMD patients had significa ntly lower thermal pain threshold, ischemic pain threshold, and ischem ic pain tolerance values; and thermal pain tolerance values also tende d to be lower. Pain sensitivity did not differ between the two groups of TMD patients. Furthermore, the submaximal effort tourniquet procedu re, which is capable of altering acute orofacial pain (Sigurdsson and Maimer, 1994) did not produce a consistent reduction in orofacial pain associated with TMD. We concluded that TMD patients are more sensitiv e to noxious stimuli than pain-free controls. These findings provide a dditional evidence that TMD is a psychophysiological disorder of the c entral nervous system which modulates emotional, physiological and neu roendocrine responses to emotional and physical stressors.