Molar-incisor hypomineralization and dental caries: A hierarchical approach in a populational-based study

The last couple of decades has seen an increasing interest in molar-incisor hypomineralization (MIH) studies. Hypomineralized defects can have several consequences such as hypersensitivity, increased dental plaque accumulation, and consequently higher caries risk. This cross-sectional study aimed to investigate the prevalence of MIH and its association with dental caries in schoolchildren from a city in southern Brazil. A random cluster sample of schoolchildren was selected. Clinical examinations were carried out to collect information on MIH (following the European Academy of Pediatric Dentistry criteria), dental caries (using the DMF-T index) and gingivitis. Socioeconomic, demographic and behavior variables were collected using a standardized questionnaire answered by the children's parents/caregivers. Prevalence ratios (PR) were estimated using Poisson regression analysis with robust variance through a hierarchical approach (p<0.05). A total of 513 schoolchildren were included in the study. MIH and caries prevalence was 19.7% and 31.6%, respectively. The mean age was 11.6 (+1.9) years. Dental caries was more prevalent in children with MIH (PR 1.39; 95% CI 1.05 - 1.85). Older children and children whose families were enrolled in conditional cash transference programs (PR 1.97 95% CI 1.47 - 2.64), and children who did not have their mother or father as the head of the family (PR 1.56 95% CI 1.06 - 2.30) presented a higher prevalence of dental caries. Our findings suggest that children with MIH are more likely to have dental caries.