Factors associated with preschool children's sleep bruxism.

Objective: To evaluate the prevalence of sleep bruxism, related factors, and quality of life of preschool children and their families.
Method: The sample was 475 children between 4 and 5 years old enrolled in schools in the city of Bauru-Brazil. Parents/legal guardians answered two questionnaires, one to assess the presence of bruxism and related factors and another that was the validated Brazilian version of the Early Childhood Oral Health Impact Scale (B-ECOHIS). Intraoral clinical examination was performed by two trained examiners (Kappa = 0.82) within the school environment. The data were analyzed using statistics and the Mann-Whitney, Kruskal-Wallis, and Spearman correlation coefficient. The significance level was p < 0.05.
Results: The prevalence of sleep bruxism was 47.4%. The highest prevalence was related to Class I canines and marked overjet, oral habits, such as nail biting, lip biting, chewing gum, and mouth breathing. Children with agitated sleep, reports of headache, and those considered aggressive, anxious, and/or shy were also more related. Conclusion: In the studied sample, sleep bruxism prevalence was high and related to important oral and general factors. Data also indicated SB as the main factor that interfered in the OHRQoL of children and their families.