Prevalence of temporomandibular disorders and associated factors: a population-based study in southern Brazil

The aim of this study was to assess the prevalence of temporomandibular disorder (TMD) and associated factors in an adult population in southern Brazil. The population-based sample (n = 4.65) included participants from Passo Fundo, a town in southern Brazil. The Fonseca Anamnestic Index was used to establish the prevalence of TMD. Sociodemographic and pathophysiologic factors and those that could cause tissue injury (trauma) were investigated. Data were analyzed using the chi-square or Fisher's exact test and Poisson regression model (p < 0.05; 95%CI). The prevalence of TMD was 13.4%, and the most prevalent symptoms were pain in the neck and/or shoulders (30.1%), headache (26.0%), and presence of popping or clicking sounds (17.0%). None of the sociodemographic factors (sex, age, marital status, occupation, and education) were associated with the prevalence of TMD (p > 0.05). Among pathophysiologic factors, those associated with the prevalence of TMD were insomnia (PR: 1.83; 95%CI: 1.07-3.12), osteoporosis (PR: 2.50; 95%CI: 1.22-5.12), rheumatoid arthritis (PR: 1.99; 95%CI: 1.07-3.68), and xerostomia (PR: 1.36; 95%CI: 1.07-1.73). The factors that could cause tissue trauma/injury associated with TMD were sleep bruxism (PR: 2.16; 95%CI: 1.01-4.62), awake bruxism (PR: 2.44; 95%CI: 1.16-5.11), tongue pressure against the teeth (PR: 4.11; 95%CI: 1.95-8.65), and neck support of objects during work (PR: 2.94; 95%CI: 0.88-9.73). The prevalence of TMD was 13.44%, and it was associated with pathophysiologic factors and those that cause tissue trauma/injury, but not with sociodemographic factors.