Common mental disorders and bruxism in adults: a birth cohort study.

OBJECTIVES: This study aimed to assess the prevalence of bruxism and its relationship with common mental disorders (CMD) during the life course of individuals. MATERIALS AND METHODS: A representative sample (n = 537) of all 5914 births occurring in Pelotas in 1982 were prospectively investigated regarding their oral health. The CMD screening was assessed through Self-Reported Questionnaire-20 (SRQ-20) at ages 22 and 30. Bruxism information was collected in the oral health survey at the age 31. Exploratory variables included demographic and socio-economic, mental health and unhealthy behaviours. Multivariate Poisson Regression analysis was used to estimate the association between bruxism and CMD. RESULTS: Bruxism prevalence was 41.1% at 31 years old. Presence of bruxism was positively associated with females (p = 0.003), lower school level (p = 0.001), and smoking habits (p = 0.021). CMD episodes were associated with bruxism (p < 0.001). Individuals presenting CMD at age of 30 years presented a 57% higher prevalence (PR 1.57; 95%CI 1.14-2.15) of bruxism, while in those individuals who presented CMD in both follow-ups (at 22 and 30 years old) the bruxism prevalence was 70% higher (PR 1.70; 95%CI 1.28-2.25). CONCLUSION: Subjects presenting signals and symptoms of common mental disorders during their life course presented higher prevalence of bruxism. CLINICAL SIGNIFICANCE: The presence of common mental disorders during life course impacts in the presence of bruxism in the adulthood. In addition, more episodes of common mental disorders were associated with higher prevalence of bruxism.