RESUMO
AIM: This was to investigate the prevalence of sleep bruxism in Brazilian schoolchildren. METHODS: A cross-sectional study was carried out examining 652 randomly selected children aged from 7 to 10 years of age from both public and private schools in Belo Horizonte, Brazil. Sleep bruxism among children was reported by parents by means of a pretested questionnaire based on the criteria of the American Academy of Sleep Disorders. The Social Vulnerability Index from Municipal database was used to determine social classification of families. A chi-square test was used with a significance level of 5%. RESULTS: Sleep bruxism was present in 230 children, showing a prevalence of 35.3%. Among the 652 children, 340 (52.0%) were girls and 312 (48.0%) were boys, predominatly of 8-year-olds (84.2%). Sleep bruxism was present in 56.5% of the girls and 43.5% of the boys. The majority of the families were of a low social vulnerability (54.2%), whereas another 45.8% were of a high social vulnerability. More than half of the children without sleep bruxism (55.2%) were of low socio-economic background. CONCLUSIONS: The high prevalence of 35.3% demonstrates the need for further research on this issue.