Longitudinal changes of symptoms of temporomandibular disorders in Japanese young adults

Longitudinal changes of symptoms of temporomandibular disorders in 275 Japanese university students were investigated through use of questionnaires in 1990 and in 1994. A comparison of the 1990 responses with the 1994 responses revealed taht the prevalences of temporomandibular joint sounds, mouth opening restriction, and pain significantly increased from 28.7% to 49.8%, from 12.7% to 22.5%, and from 7.6% to 18.5%, respectively. The increase in the prevalence of symptoms mainly resulted for students who did not have symptoms of temporomandibular disorders at the first examination. Subjects who had been frequently aware of symptoms of temporomandibular disorders showed a tendency toward a decrease in their frequency of awareness. Although 66 students (24.0%) reported discomfort from symptoms of temporomandibular disorders during the period, only three (1.1%) visited medical facilities to receive treatment. These results suggest that symptoms of temporomandibular disorders evaluated through the use of questionnaires are longitudinally fluctuant, and that few students developed temporomandibular disorders.