title: Dental trauma: prevalence and risk factors in schoolchildren.
abstract: OBJECTIVE
  This cross-sectional study aimed to determine the prevalence of traumatic injury to the permanent incisors in 8- to 12-year-old children and to test associations between dental trauma and nutritional status and physical activity level, with adjustment for demographic, behavioral, and psychosocial variables. Differences in risk factors between sexes were also assessed.
  
  
  METHODS
  Two-stage cluster sampling was used to select 1210 children in 20 public and private schools in Pelotas, Brazil, for study participation. Dental trauma was assessed using the O'Brien criteria. Parents provided information about socioeconomic characteristics and their children's history of trauma in early childhood via questionnaire. Children were interviewed to obtain demographic and psychosocial information and to assess physical activity level. Anthropometric measures were collected for body mass index calculation. Hierarchical Poisson regression was used for data analyses.
  
  
  RESULTS
  The prevalence of dental trauma was 12.6% [95% confidence interval (CI), 10.8-14.7%] in the entire sample; it increased with age from 7.2% at 8 years to 21.5% at 12 years. In the adjusted analysis, dental trauma was more prevalent in boys [prevalence ratio (PR) = 0.71; 95% CI, 0.50-0.99], older children (PR = 3.57; 95% CI, 1.73-7.34), those with inadequate lip coverage (PR = 2.03; 95% CI, 1.22-3.38), and those with histories of trauma in the primary dentition (PR = 2.60; 95% CI, 1.80-3.75). In a sex-stratified analysis, dental trauma was more prevalent in overweight/obese boys (PR = 1.65; 95% CI, 1.10-2.92). No significant association was found with socioeconomic variables, psychosocial characteristics, physical activity level, or school retention among boys or girls.
  
  
  CONCLUSIONS
  The pronounced increase in the prevalence of dental trauma with age highlights the need to establish preventive strategies among schoolchildren. The risk of dental injury was increased in overweight/obese boys and children with histories of dental trauma in early childhood, confirming the existence of accident-prone children.
authors.affiliation: Department of Social and Preventive Dentistry, Post-Graduate Program in Dentistry, School of Dentistry, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: Marília Leão
authors.initials: ML
authors.lastname: Goettems
authors.forename: Dione Dias
authors.initials: DD
authors.lastname: Torriani
authors.forename: Pedro Curi
authors.initials: PC
authors.lastname: Hallal
authors.forename: Marcos Britto
authors.initials: MB
authors.lastname: Correa
authors.forename: Flávio Fernando
authors.initials: FF
authors.lastname: Demarco
mesh_terms: D000886:Anthropometry; D001938:Brazil / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007180:Incisor; D008297:Male; D009043:Motor Activity; D009752:Nutritional Status; D015995:Prevalence; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D018677:Tooth Injuries / Q000453:epidemiology*
keywords: body mass index; children; dental trauma; epidemiology; physical activity