Abstract
Background and aims. Temporomandibular disorders (TMDs) are the most common condition affecting the temporomandibular
joint and associated structures. The aim of this study was the epidemiologic evaluation of TMDs and related
factors in a group of Iranian adolescents.
Materials and methods. This descriptive cross-sectional survey included a sample of 800 high school students (400
girls and 400 boys) aged 14 to18 years, in Mashhad, Iran, selected using cluster sampling. Examiners completed questionnaires
and performed the clinical examinations. Data were analyzed with the Chi-square and Fisher exact tests.
Results. The prevalence of TMDs in the studied sample was 34.7%. The most common signs of TMDs were clicking,
muscle tenderness and TMJ tenderness. The most prevalent predisposing factors of TMDs were clenching, premature contact
in protrusive movement and bruxism. A clear predominance was seen in girls (40.5%) compared with boys (29%) (P =
0.001).
Conclusion. Signs and symptoms of TMDs were prevalent in Iranian adolescents with a clear female predominance