Introduction: Information about the distribution of malocclusion in the population and identification of factors and conditions associated with it could help researchers build models to understand its occurrence and help public-health policy makers improve interventions. The aim of this study was to assess the severity of occlusal disorders in Brazilian adolescents, 12 and 18 years old, and to investigate associations between occlusal disorders and demographic, socio-environmental, and clinical variables.
Methods: Secondary data from a cross-sectional study, including 13,801 dental occlusion status records from a probabilistic sample randomly selected from public and private schools in 131 cities in the state of São Paulo, Brazil, were analyzed according to the dental aesthetic index (DAI). The proportion of DAI scores greater than 30 were compared between ages, sexes, white and nonwhite students, urban and rural dwellers, and private and public school students; and they were compared with variables such as access to fluoridated tap water and city population, and with clinical aspects such as the care index (CI) and the decayed, missing, filled teeth (DMFT) index. Data analysis included frequency distribution calculation and multiple logistic regression modeling.
Results: The mean DAI score for the sample was 24.33 (SD 7.54), and 16.5% of the subjects had DAI scores of 30 or more (severe or very severe malocclusion). The rate of DAI >31 was significantly higher among 12-year-olds, nonwhites, public-school students, those from smaller municipalities, those without fluoridated tap water, and those with a CI <51%, a DMFT score >4 at age 12 years, or a DMFT score >6 at age 18 years. At age 18, fewer subjects had DAI scores >30; the components responsible for this reduction were spacing in at least 1 incisal segment, midline diastema > or =1, and anterior maxillary overjet > or =4.
Conclusion: Some socio-environmental factors are associated with severity of malocclusion in adolescents.