Temporomandibular disorders and chronic pain: disease or illness?

Temporomandibular disorders (TMD) are examined from a biopsychosocial or illness perspective. Data are reviewed in accordance with the concept that TMD is a chronic pain condition that shares many features with other common chronic pain conditions. TMD is placed within the same biopsychosocial model currently used to study and manage all common chronic pain conditions. The concept of chronic pain dysfunction, which has emerged as a critical consideration for chronic pain research and management, is also reviewed. Most chronic pain patients seem to bear their condition adequately and thus maintain adaptive levels of psychosocial function. By contrast, a psychosocially dysfunctional segment of the chronic pain population appears unable to cope as well and demonstrate higher rates of depression, somatization, and health care use, even though persons in this segment are not different from their functional peers on the basis of observable organic pathology. Finally, data are reviewed from longitudinal, epidemiologic, and experimental intervention studies that substantiate these two perspectives.