Temporomandibular joint sounds in adolescents: a longitudinal study.

A 2-year longitudinal study on signs and symptoms of mandibular dysfunction was performed with 285 17-year-old adolescents living in a certain geographic area in Skellefteå, Sweden. Crepitation was neither reported nor recorded in any subject. Both reports and recordings of TMJ clicking sounds fluctuated with time. The 2-year period prevalence was 24%, and 5.8% consistently reported TMJ clicking sounds. The corresponding figures for clinically recorded clickings were 36% and 9.3%, respectively. Both reported and recorded joint sounds were significantly more frequently found in 19-year-old girls than in boys. No consistent pattern of relationships between reported and recorded clicking sounds and single factors obtained by the questionnaire or clinically recorded variables could be found. Palpation tenderness in three muscle sites was to a varying degree related to both reports and recordings of clicking. Each year, significant relationships were found between reports of TMJ sounds and symptom indices. Recorded sounds were significantly related to a clinical index in the two oldest age groups. The prevalence of TMJ clicking sounds increases with age, and girls are more prone to have them than boys. In view of the natural longitudinal fluctuations, most clickings only need to be supervised, and when there is a demand for treatment, reversible methods are advocated in adolescents.