title: Dental trauma occurrence and occlusal characteristics in Brazilian preschool children.
abstract: OBJECTIVE
  The purpose of this study was to analyze the association between dental trauma and occlusal traits in the primary dentition.
  
  
  METHODS
  Five hundred and one 24- to 71-month-old children, attending both private and public schools in Pelotas, Rio Grande do Sul, Brazil,  were included. Clinical examinations were performed at each school. Occurrence of dental trauma was assessed using the Andreasen and Andreasen classification. Occlusal characteristics used in this study were: overjet; open bite; overbite; anterior crossbite; crowding and rotated teeth occurrence;  and canine class. The occlusion type was classified according to the World Health Organization. A questionnaire was sent to parents to obtain socioeconomic data. Descriptive statistics were used, as well as chi-square tests (for heterogeneity or linear trend; P ≤ .05) and Fisher's exact  test.
  
  
  RESULTS
  The prevalence of dental trauma was 40% (95% confidence interval=35-44). Of all children examined, 20% showed normal occlusion, 42% mild malocclusion, and 38% moderate/severe malocclusion. Dental trauma was associated with overjet ≥ 3 mm (P=.02), overbite ≥ 3 mm  (P=.01), and canine class (P=.04). Children bearing mild or moderate/severe malocclusion presented greater dental trauma (P<.01).
  
  
  CONCLUSIONS
  The findings of this study emphasize the importance of preventing dental trauma, especially in children presenting increased overjet, overbite,  or canine Class II.
authors.affiliation: Department of Social and Preventive Dentistry, Federal University of Pelotas, Pelotas, Rio Grande do Sul, Brazil.
authors.forename: Marília Leão
authors.initials: ML
authors.lastname: Goettems
authors.forename: Marina Sousa
authors.initials: MS
authors.lastname: Azevedo
authors.forename: Marcos Britto
authors.initials: MB
authors.lastname: Correa
authors.forename: Catiara Terra Da
authors.initials: CT
authors.lastname: Costa
authors.forename: Flávia Priescht
authors.initials: FP
authors.lastname: Wendt
authors.forename: Helena Silveira
authors.initials: HS
authors.lastname: Schuch
authors.forename: Maria Laura Menezes
authors.initials: ML
authors.lastname: Bonow
authors.forename: Ana Regina
authors.initials: AR
authors.lastname: Romano
authors.forename: Dione Dias
authors.initials: DD
authors.lastname: Torriani
mesh_terms: D001938:Brazil; D002648:Child; D002675:Child, Preschool; D003766:Dental Occlusion; D005260:Female; D006801:Humans; D008297:Male; D011795:Surveys and Questionnaires; D014947:Wounds and Injuries / Q000150:complications / Q000453:epidemiology*