Pages 315-320, Language: EnglishSato / Goto / Kawamura / MotegiThe natural course of untreated nonreducing disc displacement of the temporomandibular joint was evaluated in 52 patients (total of 57 affected temporomandibular joints). The association between the clinical findings at the initial visit and the outcome at 12 months for the age, range of motion for maximum mouth opening, intercuspal-occlusal relationship, morphology of the mandibular fossa and the articular eminence, and the locking d uration was evaluated. Good resolution was seen in 59.6% of the patients. The patients with good resolution were significantly younger than those with poor resolution (P .05, two-tailed t test); however, there were no differences in any other factors between the patients with good resolution and those with poor resolution. Natural resolution of clinical signs and symptoms was suggested for the majority of patients with nonreducing disc displacement of the TMJ, and a younger age at the initial visit appears to be a positive factor in the prognosis.