RESUMO
BACKGROUND: Malocclusion is a condition frequently seen in primary dentition due to the interaction of environmental, genetic and behavioural factors. The occurrence of some types of malocclusions can have an impact on oral health-related quality of life in children. Hence, the present study aimed to verify the impact of primary dentition malocclusion on oral health-related quality of life in preschool children. METHODS: A population-based cross-sectional study was conducted in Florianopolis, Brazil, with a representative sample of 1050 preschoolers aged between 2 and 5 years, randomly selected. Parents answered the Brazilian version of the Early Childhood Oral Health Impact Scale and also to a questionnaire on socio-economic indicators. Data obtained from the questionnaire were obtained by item response theory based on model of gradual response. The malocclusion assessed was: anterior open bite, increased overjet and posterior crossbite. Poisson regression model was employed for multivariate analysis (P < 0.05). RESULTS: Malocclusion was observed in 36.7% of the children. Of these, 11.4% were anterior open bite, 67.2% were increased overjet, and 21.4% were posterior crossbite. Malocclusion's impact on oral health-related quality of life was 28.6%. In children aged 4-5 years, the prevalence of malocclusion's impact on quality of life was 49.5% higher than in children aged 2-3 years. Statistical analysis showed that preschool children with malocclusion showed no significant impact on quality of life. CONCLUSIONS: The findings of the present study indicate that the occurrence of primary dentition malocclusion has no impact on the quality of life of children aged 2-5 years.