Temporomandibular joint and muscle disorder (TMJMD) is one of the most prevalent types of musculoskeletal disorders. The major goal of the study was to more objectively quantify clinically meaningful relief for TMJMD treatment outcomes by using the new metric of minimal clinically important difference (MCID). Pre- to post-treatment changes on a number of self-report measures were evaluated in a cohort of 101 acute TMJMD patients. An anchor-based MCID approach was employed, with an objective chewing performance measure serving as the clinical outcome of interest. Using a Receiver Operating Curve analysis, it was found that the Physical Component Scale (PCS) of the SF-36 was the most robust self-report measure to use as the MCID in a TMJMD patient population.