Prevalence of malocclusion in children aged 9 to 12 years old in the city of Nova Friburgo, Rio de Janeiro State, Brazil

Introduction: Knowledge of a population’s epidemiological situation is important in the planning and provision of dental services. Objectives: Assess the prevalence of malocclusion in children aged 9 to 12 years old from public schools in the city of Nova Friburgo, Rio de Janeiro State, Brazil. Methods: A randomly selected sample consisting of 407 children (53.1% female) who were evaluated by a trained professional, after parental consent. Results: The most prevalent malocclusions were crowding (45.5%), excessive overjet (29.7%), posterior crossbite (19.2%), anterior diastema (16.2%), partially erupted teeth (12.0%) and excessive overbite (10.8%). Class I molar relationship prevailed (76.7%). The presence of diastemas was higher in females and excessive overbite was more prevalent in males, both in mixed dentition. Negative overjet and the presence of partially erupted teeth had a higher prevalence in permanent dentition. Conclusion: It was observed that the mere evaluation of malocclusion prevalence does not reveal case severity or treatment need, both of which are important factors in public health planning.