This article describes a practical, quantitative method of measuring.changes in temporomandibular disorder (TMD) symptoms in a dental practice. It applies the TMJ Scale(TM)* to produce a number of clinically important measures of treatment effectiveness. Those measures include pre- and post-treatment symptom severity, percent of patients improved, level of improvement, and percent of patients converting to non-symptomatic after treatment. All of these outcome parameters were applied to a sample of the practice and to subgroups based on age, sex and problem length. The treated patients were compared to a group of diagnosed but untreated patients. The specific target symptoms of TMD are analyzed including pain, palpation pain, joint dysfunction and limited range of motion of the mandible. In addition, the overall symptom severity of the TM disorder, psychological factors and stress are studied, leading to an assessment of symptom change. The results support the concept that patients with acute problems are more treatment responsive than are patients with chronic problems. This suggests that careful screening and earlier detection of TMD may have an important impact on ultimate treatment outcome.