title: Epidemiologic Study of Molar-incisor Hypomineralization in Schoolchildren in North-eastern Brazil.
abstract: OBJECTIVE
  To determine the prevalence of molar-incisor hypomineralization (MIH) 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, Piauí, 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 [CI] 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 CI 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 CI equals 1.22 to 2.12) and between MIH and respiratory distress at birth (PR equals 1.83; 95 percent CI 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.
authors.affiliation: Department of Pathology and Dentistry Clinic, School of Dentistry, Federal University of Piauí, Teresina, Piauí, Brazil. mdmlima@gmail.com.
authors.forename: Marina de Deus Moura
authors.initials: Mde D
authors.lastname: de Lima
authors.affiliation: Private practice, Teresina, Piauí, Brazil.
authors.forename: Maria Janaína Barroso
authors.initials: MJ
authors.lastname: Andrade
authors.affiliation: Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
authors.forename: Neusa Barros
authors.initials: NB
authors.lastname: Dantas-Neta
authors.affiliation: Private practice, Teresina, Piauí, Brazil.
authors.forename: Natália Silva
authors.initials: NS
authors.lastname: Andrade
authors.affiliation: Department of Pathology and Dentistry Clinic, School of Dentistry, Federal University of Piau&iacute, Teresina, Piauí, Brazil.
authors.forename: Rafael José Pio Barbosa
authors.initials: RJ
authors.lastname: Teixeira
authors.affiliation: Department of Pathology and Dentistry Clinic, School of Dentistry, Federal University of Piauí, Teresina, Piauí, Brazil.
authors.forename: Marcoeli Silva
authors.initials: MS
authors.lastname: de Moura
authors.affiliation: Department of Pathology and Dentistry Clinic, School of Dentistry, Federal University of Piauí, Teresina, Piauí, Brazil.
authors.forename: Lúcia de Fátima Almeida
authors.initials: Lde F
authors.lastname: de Deus Moura
mesh_terms: D000293:Adolescent; D001938:Brazil; D002648:Child; D003430:Cross-Sectional Studies; D003744:Dental Enamel Hypoplasia / Q000453:epidemiology; D006801:Humans; D007180:Incisor; D008963:Molar