Sleep bruxism: population based study in people with 18 years or more in the city of Rio Grande, Brazil.

Objective: To evaluate the prevalence of sleep bruxism, as well as its principal signs and symptoms, in the city of Rio Grande. Evaluate the association of sleep bruxism with gender, age, education and psychological stress.
Method: The study was cross-sectional type. A representative sample of the population (1280 people residing in the urban area of the city aged greater than or equal to 18 years old) were interviewed. The evaluation of sleep bruxism was by mean of questionnaire based on diagnostic criteria of the International Classification of Sleep Disorders.
Results: The prevalence of sleep bruxism found in the population was 8,1% (confidence interval of 95% - 95%CI - 6,6 - 9,5). Among the signs and symptoms of dysfunction used for the diagnosis of sleep bruxism, tooth wear (70,3%) and pain in masticatory muscles (44,5%) were the most frequently reported by people who report teeth grinding during sleep. There was no significant difference in the prevalence of sleep bruxism between sexes. People older than 40 had a higher prevalence of sleep bruxism. The dysfunction was associated with a higher level of education (prevalence ratio - PR = 1.92; 95%CI 1,35 - 2,72) and psychological stress (PR 1,76; 95%CI 1,11 - 2,81).
Conclusion: There was a significant prevalence of sleep bruxism in the general population, causing various damages to the Stomatognathic system. The psychological stress is a risk factor for this dysfunction.