A Longitudinal Evaluation of the Effects of Orthodontic Treatment on Clinical Signs and Symptoms of Temporomandibular Disorders.

Temporomandibular disorders (TMD) is the term officially adopted by the American Dental Association (Griffiths, 1983) to denote a group of clinical problems involving the temporomandibular joints, the masticatory musculature or both (McNeill, 1990, 1990a). In the past, these problems have been viewed as one encompassing syndrome, however, current research suggests that temporomandibular disorders are related, distinct disorders in the masticatory system with many common features (Bell, 1982, 1990; Griffiths, 1983a). Joint sounds are the most common symptoms found in the adult populations studied epidemiologically, and masticatory muscle pain from palpation is the most common sign (Helkimo, 1979; Schiffman and Fricton, 1988). The most common initial symptom for patients seeking treatment is pain in the temporomandibular joints and muscles of mastication