An epidemiological sample of 114 subjects was followed longitudinally from the age of 15 to 35 years with regard to treatment received, treatment demand, and treatment need for temporomandibular disorders (TMD). Some kind of TMD treatment had been provided to 18% of the subjects during the 20-year follow-up period. Eighty-five percent of those who had received previous TMD treatment reported that the treatment had had a positive effect on their symptoms. The estimated present need for treatment was 11%, but, in line with several other investigations, the active demand for such treatment was much less (3%). From age 15 to 25 years, a small but gradual increase of clinical signs of dysfunction was found. From the age of 25 to 35 years, however, a significant reduction of such signs was noted. One explanation for this reduction of clinical signs and symptoms of TMD might be the stomatognathic treatment received. It was concluded that 18% of the subjects had received some TMD treatment during the 20-year follow-up period. Only 3% still had a demand for such treatment at age 35.