Prevalence of temporomandibular disorders in clinics and health centers in Tehran during summer 2001

Temporomandibular disorders (TMD) are defined as a series of signs and symptoms related to masticatory apparatus disorders. The prevalence of TMD (signs or symptoms) is high. Prevalent diagnostic and simple treatment can prevent the occurrence of sequeles. Due to different statistics on prevalence of TMD in different society, the aim of the present study was to investigate the prevalence of temporomandibular disorders in dental clinics of Tehran city. Methods & Materials: One thousands and five hundred and three subjects were collected from 20 clusters (clinics in Tehran). The research methods were descriptive and analytical. 3 students with two supervising prosthodontists completed two questionnaires for signs & symptoms with ICC = 0.819 and kappa = 0.772 via observation and interview. For statistical analysis, t and chi – square tests were used. The most frequently reported symptoms were: joint sounds (18.6%), muscle tenderness (9.1%) and joint pain (7.7%). The most frequently signs were: joint sounds (30.2%), deviation patterns in mouth opening (23.4%), muscle tenderness (17%), joint pain (6%) and limited mouth opening (1.94%). The prevalence of symptoms and signs were 36.5% and 45.7%, with a significant relationship between them (P<0.001). The prevalence of TMD was 58.7%. There were significant relationships between TMD & bruxism and TMD & history of trauma (P<0.001). The prevalence of inflammatory disease of temporomandibular joint demonstrated significant difference between different age groups (P<0.001) and increased with age. The prevalence of TMD in clinical centers of Tehran was more than 50% of population. Due to the significant relationship between bruxism, trauma and prevalence of TMD, awareness of society for prevention and beginning the necessary treatments seems indispensible.