Traumatic dental injury among 12-year-old South Brazilian schoolchildren: prevalence, severity, and risk indicators.

An increasing prevalence of traumatic dental injury (TDI) has been reported in the last few decades. The aim of this study was to assess the prevalence and severity of TDI and its association with socio-demographics and physical characteristics in the anterior permanent teeth of 12-year-old Brazilian schoolchildren. A cross-sectional study was carried out in a population-based sample of 1528 subjects attending 33 public and nine private schools (response rate of 83.17%). A single calibrated examiner performed the clinical examinations at the schools and recorded the TDI index (Children's Dental Health Survey criteria), overjet and lip coverage. Height and weight were measured to calculate the body mass index (BMI). Parents/legal guardians answered a questionnaire containing socio-demographic questions. The relationships among TDI, socio-demographic variables and physical characteristics were assessed by survey Poisson regression models. The prevalence of TDI was 34.79% (mild trauma = 24.37%; severe trauma = 10.43%). Male schoolchildren (RR = 1.41, 95% CI = 1.23-1.61, P = 0.002) and schoolchildren from low socioeconomic status (RR = 1.32, 95% CI = 1.07-1.64, P = 0.021) were more likely to present at least one tooth with TDI, whereas students attending 7th grade (advanced students) were less likely to experience TDI (RR = 0.59, 95% CI = 0.43-0.82, P = 0.012). Regarding the severity analysis, students of mid-high (RR = 1.46, 95% CI = 1.09-1.94, P = 0.022), mid-low (RR = 1.68, 95% CI = 1.01-2.77, P = 0.045) and low (RR = 1.78, 95% CI = 1.11-2.85, P = 0.027) socioeconomic status were more likely to have mild trauma when compared with schoolchildren of high socioeconomic status. No significant association between severe trauma and socioeconomic status was observed. In conclusion, this study showed a high prevalence of TDI in 12-year-old Brazilian schoolchildren. Socio-demographic data and school achievement were associated with TDI.