title: Trends in the prevalence of traumatic crown injuries and associated factors in Brazilian preschool children: 10-year observational data.
abstract: OBJECTIVE
  To assess trends in the prevalence of traumatic crown injuries (TCI) in children aged 1-4 years living in Diadema city (Brazil) and to investigate whether TCI were associated with socio-demographic and clinical variables.
  
  
  METHODS
  Six cross-sectional surveys with representative samples were carried out from 2002 to 2012 following the same criteria and methodology. A total of 6389 children were evaluated and systematically selected on the National Children's Vaccination day. Calibrated examiners performed the children's oral examination for TCI according to Andreasen's criteria. Chi-square test for trends was used to perform comparative analysis. Poisson regression was used to associate TCI to socio-demographic and clinical variables.
  
  
  RESULTS
  The prevalence of TCI in 2002 for preschool children aged 1, 2, 3 and 4 years was 4.5%, 11.4%, 14% and 13.9%, respectively, and the prevalence in 2012 for the same age groups was 10.4%, 15.9%, 25.7% and 28.1%, respectively. There was a significant increase in the prevalence of TCI for all age groups and for the total sample (P < 0.05). Children's age was associated with TCI in all the surveys. Male gender, presence of anterior open bite and inadequate lip coverage were associated with TCI in some surveys along the years (P < 0.05).
  
  
  CONCLUSIONS
  This study has shown an increase of TCI prevalence in Brazilian preschool children in the last 10 years and its association with children's age, male gender, presence of anterior open bite and inadequate lip coverage. However, this increase does not seem to be relevant to decisions on public policy.
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, School of Dentistry, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Tello
authors.affiliation: Faculdade São Leopoldo Mandic, School of Dentistry, Campinas, SP, Brazil.
authors.forename: Gabriela Cunha
authors.initials: GC
authors.lastname: Bonini
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, School of Dentistry, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Christiana
authors.initials: C
authors.lastname: Murakami
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, School of Dentistry, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Jenny
authors.initials: J
authors.lastname: Abanto
authors.affiliation: Faculdade São Leopoldo Mandic, School of Dentistry, Campinas, SP, Brazil.
authors.forename: Luciana Butini
authors.initials: LB
authors.lastname: Oliveira
authors.affiliation: Department of Orthodontics and Pediatric Dentistry, School of Dentistry, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Bönecker
mesh_terms: D001938:Brazil; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D019228:Tooth Crown / Q000293:injuries*; D018677:Tooth Injuries / Q000453:epidemiology*
keywords: dental injuries; dental trauma; epidemiology; preschool children; primary teeth