Because of a lack of substantial scientific data, the efficacy of occlusal therapy for the management of temporomandibular disorders (TMD) is still controversial. Of a total of 1405 consecutive TMD patients examined over the last 10 years, 369 (26.3%) were determined to have completed treatment at least 1 year before the present survey. A sample questionnaire was mailed to each patient in this sample population. The questionnaire failed to reach 46 patients; of the 323 patients who received the questi onnaire, 260 (80.5%) responded. The mean duration of time between their last visit and this survey was 3.7 years. The questionnarie elicited information on treatment outcomes, present treatment needs, and current signs and symptoms. Participants were divided into two treatment groups: (a) those who underwent some occlusal therapies (Phase II) following successful reversible therapies (Phase I) (20 men and 114 women); and (b) those who underwent reversible therapy only (33 men and 93 women). Participants were further differentially diagnosed into five diagnostic subgroups of TMD, based on the clinical examination at the initial visit, tomography, and, for some patients, magnetic resonance imaging. The subgroups included myalgia, arthralgia, anterior disc displacement with and without reduction, and osteoarthritis/osteoarthrosis. Only 12.3% of the total population surveyed reported lack of improvement to an acceptable level and further need for treatment. The remaining patients reported satisfactory results in the reduction of TMD symptomatology and no furthe rneed for treatment, because their symptoms had either disappeared or improved to an acceptable level. Regardless of treatment groups and diagnostic subgroups, the current subjective signs and symptoms were negligible in most patients, and mean mouth openings were in the normal range. No particular diagnostic subgroups seemed to have significantly better outocme following Phase II occlusal therapy. These results suggest that the majortiy of TMD signs and symptoms improve to an acceptable level with only reversible therapy, and the long-term value of additional occlusal therapy following reversible therapy is minimal. Therefore, permanent occlusion-changing therapies apparently are not generally needed to maintain TMD symptom reduction over time.