Epidemiologic Study of Molar-incisor Hypomineralization in Schoolchildren in Northeastern Brazil

Purpose: To determine the prevalence of molar-incisor hypormineralization (MIN) in children and possible factors associated with this disorder. Methods: This was a cross-sectional observational study of 594 11- to 14-year-olds from Teresina, Piaui, Brazil. The diagnosis of MIH was made based on criteria set by the European Academy of Pediatric Dentistry. To investigate possible associated factors, mothers completed a questionnaire. A descriptive analysis of the data, chi-square, Mann-Whitney, and Fisher tests and Poisson regression (PR) were performed. Results: The prevalence of MIH was 18.4 percent (95 percent confidence interval [Cl] equals 15.20 to 21.50). The maxillary molars were the teeth most affected by MIH (36.1 percent). MIH patients showed a higher number of mean DMF-T (PR equals 2.18; 95 percent Cl equals 1.46 to 2.85) than those not affected by the condition. There was an association between MIH and preterm birth (PR equals 1.76; 95 percent Cl equals 1.22 to 2.12) and between MIH and respiratory distress at birth (PR equals 1.83; 95 percent Cl equals 1.25 to 2.18). Conclusions: The prevalence of MIH in schoolchildren was 18.4 percent. Those with MIH had a greater mean DMF-T than those without MIH. Preterm birth and respiratory distress were associated with MIH.