To evaluate the clinical course of temporomandibular joint osteoarthrosis and internal derangement, 99 patients who had received nonsurgical treatment for temporomandibular problems were reexamined 30 years after the original treatment. Results were compared with information obtained from patients' clinical examinations before and a few years after the original treatment as well as information from the clinical examination of 35 control subjects. During the first years after treatment, the main signs of temporomandibular joint osteoarthrosis and internal derangement decreased significantly. In the next three decades, very few changes were noticed. Clicking and crepitus were the most common remaining signs. These signs, however, did not appear to be bothersome to the patients. It was concluded that the disorders in question eventually reach a state of quiescence.