title: Exploring factors associated with traumatic dental injuries in preschool children: a Poisson regression analysis.
abstract: OBJECTIVE
  This cross-sectional study aimed to investigate the factors associated with dental trauma in preschool children using Poisson regression analysis with robust variance.
  
  
  METHODS
  The study population comprised 888 children aged 3- to 5-year-old attending public nurseries in Canoas, southern Brazil. Questionnaires assessing information related to the independent variables (age, gender, race, mother's educational level and family income) were completed by the parents. Clinical examinations were carried out by five trained examiners in order to assess traumatic dental injuries (TDI) according to Andreasen's classification. One of the five examiners was calibrated to assess orthodontic characteristics (open bite and overjet). Multivariable Poisson regression analysis with robust variance was used to determine the factors associated with dental trauma as well as the strengths of association. Traditional logistic regression was also performed in order to compare the estimates obtained by both methods of statistical analysis.
  
  
  RESULTS
  36.4% (323/888) of the children suffered dental trauma and there was no difference in prevalence rates from 3 to 5 years of age. Poisson regression analysis showed that the probability of the outcome was almost 30% higher for children whose mothers had more than 8 years of education (Prevalence Ratio = 1.28; 95% CI = 1.03-1.60) and 63% higher for children with an overjet greater than 2 mm (Prevalence Ratio = 1.63; 95% CI = 1.31-2.03). Odds ratios clearly overestimated the size of the effect when compared with prevalence ratios.
  
  
  CONCLUSIONS
  These findings indicate the need for preventive orientation regarding TDI, in order to educate parents and caregivers about supervising infants, particularly those with increased overjet and whose mothers have a higher level of education. Poisson regression with robust variance represents a better alternative than logistic regression to estimate the risk of dental trauma in preschool children.
authors.affiliation: Department of Pediatric Dentistry, Universidade Luterana do Brasil, Canoas, Brazil. cafeldens@terra.com.br
authors.forename: Carlos Alberto
authors.initials: CA
authors.lastname: Feldens
authors.forename: Paulo Floriani
authors.initials: PF
authors.lastname: Kramer
authors.forename: Simone Helena
authors.initials: SH
authors.lastname: Ferreira
authors.forename: Mônica Hermann
authors.initials: MH
authors.lastname: Spiguel
authors.forename: Marcela
authors.initials: M
authors.lastname: Marquezan
mesh_terms: D000367:Age Factors; D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D004522:Educational Status; D005006:Ethnicity; D005260:Female; D006801:Humans; D007180:Incisor / Q000473:pathology; D016015:Logistic Models; D008297:Male; D016017:Odds Ratio; D024343:Open Bite / Q000150:complications; D016012:Poisson Distribution; D015995:Prevalence; D012044:Regression Analysis; D012307:Risk Factors; D012737:Sex Factors; D012923:Social Class; D011795:Surveys and Questionnaires; D018677:Tooth Injuries / Q000453:epidemiology* / Q000209:etiology; D014094:Tooth, Deciduous