Purpose: The purpose of this study was to examine the natural course of anterior disc displacement without reduction in the temporomandibular joint (TMJ).
Patients and methods: The subjects were patients who had been diagnosed as having anterior disc displacement without reduction in the TMJ, but who had not undergone any treatment. Forty-four patients were followed for 6 months, 38 for 12 months, and 22 for 18 months. Clinical signs and symptoms were evaluated at each follow-up, and the incidence of successful resolution was determined using the criteria established in 1984 by the American Association of Oral and Maxillofacial Surgeons.
Results: The range of motion increased at each time during the follow-up period. Tenderness in the TMJ and the masticatory muscles was alleviated, but the noise in the TMJ remained unchanged at each follow-up time. The incidence of successful resolution was 34.1% at 6 months, 50.0% at 12 months, and 68.2% at 18 months.
Conclusions: The clinical signs and symptoms of anterior disc displacement without reduction tend to be alleviated during the natural course of the condition. This should be taken into consideration when anterior disc displacement without reduction is treated.