title: Malocclusion in preschool children: prevalence and determinant factors.
abstract: OBJECTIVE
  To evaluate the prevalence of malocclusion and associated factors in the primary dentition of preschoolers in the city of Diamantina, Brazil.
  
  
  METHODS
  A cross-sectional study was carried out with 381 children aged 3-5 years treated at the 10 basic health care units in the city during immunisation campaigns. The dependent variables (presence of malocclusion, open bite, crossbite and crowding) were evaluated through a clinical oral exam. The independent variables (gender, age, health problems, breastfeeding, bottle feeding, harmful oral habits, mother's schooling, household income and number of children in the home) were collected through interviews. Statistical analysis involved descriptive analysis, Chi square test and Poisson regression.
  
  
  RESULTS
  The prevalence of malocclusion was 32.5%. Open bite was the most frequent type of malocclusion. Children with a history of bottle feeding (PR 1.74; 95% CI 1.24-2.44) and those with harmful oral habits (PR 1.49; 95% CI 1.23-1.99) had greater prevalence rates of malocclusion. Greater prevalence rates of open bite were also found in children with a history of bottle feeding (PR 5.00; 95% CI 1.99-12.5) and those with harmful oral habits (PR 2.90; 95% CI 1.59-5.29), whereas greater prevalence rates of crossbite were found in boys (PR 1.79; 95% CI 1.10-2.91) and were associated with mother's schooling (PR 1.91; 95% CI 1.20-3.06).
  
  
  CONCLUSIONS
  A history of bottle feeding and the presence of harmful oral habits were identified as determinants for the occurrence of malocclusion in preschoolers.
authors.affiliation: Federal University of Vales do Jequitinhonha e Mucuri, Rua da Glória, 187, Centro, Diamantina, Minas Gerais, Brazil, patriciafaria.faria09@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Corrêa-Faria
authors.forename: M L
authors.initials: ML
authors.lastname: Ramos-Jorge
authors.forename: P A
authors.initials: PA
authors.lastname: Martins-Júnior
authors.forename: R G
authors.initials: RG
authors.lastname: Vieira-Andrade
authors.forename: L S
authors.initials: LS
authors.lastname: Marques
mesh_terms: D001903:Bottle Feeding / Q000706:statistics & numerical data; D001938:Brazil / Q000453:epidemiology; D001942:Breast Feeding / Q000706:statistics & numerical data; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003769:Dental Occlusion, Traumatic / Q000453:epidemiology; D004522:Educational Status; D005260:Female; D005386:Fingersucking; D006801:Humans; D007182:Income / Q000706:statistics & numerical data; D008297:Male; D008310:Malocclusion / Q000453:epidemiology*; D009035:Mothers / Q000193:education; D009259:Nail Biting; D009752:Nutritional Status; D024343:Open Bite / Q000453:epidemiology; D015995:Prevalence; D012737:Sex Factors; D014094:Tooth, Deciduous