Prevalence of temporomandibular joint dysfunction (TMJD) in Chinese children and adolescents. A cross-sectional epidemiological study.

The aim of this study was to investigate the prevalence of temporomandibular joint dysfunction (TMJD) in Chinese children and adolescents, and the relationship between TMJD and type of occlusion. The sample consisted of 3105 Chinese children, 3-19 years of age, divided into four groups by the stage of dental maturation. The prevalence of TMJD for the entir group was 17.9 per cent and there was no significant sex difference. TMJD increased in the mixed and early permanent dentitions, but decreased in the permanent and deciduous dentitions. In the subjects with TMJD, the most common sign was sound (87.7 per cent), followed by abnormal jaw movement (23.6 per cent), but pain was registered in 0.6 per cent only. A single sign was registered in 88.5 per cent, a combination of sound and abnormal jaw movement in 11.0 per cent, and combinations of other signs in less than 1.0 per cent. Sound as a single sign increased with the specific stages of dental development (P < 0.001).