The evolution of thinking regarding temporomandibular disorders (TMDs) has included many theories of etiology and pathogenesis, ranging from anatomical features of the temporomandibular joint (TMJ), to occlusal abnormalities, to behavioral origins such as bruxism. Many people with TMDs use over-the-counter medications to reduce their pain. The case studies in this chapter illustrate some of the variation in symptoms, duration of pain and treatment history typically seen in patients at a TMD clinic. Epidemiological research in the area of TMDs has focused primarily on estimates of prevalence rates for signs and symptoms, and descriptions of characteristics of TMD cases versus controls. Rational treatment of TMDs includes pharmacological adjuncts to optimize other treatment modalities such as splint therapy, physical therapy or biofeedback. Chronic, debilitating TMD pain that persists despite comprehensive multidisiplinary treatment may necessitate the long-term use of opiates.