Prevalence and correlates of traumatic injuries to the permanent teeth of schoolchildren aged 9-14 years in Belo Horizonte, Brazil.

A cross-sectional survey was carried out on 3702 boys and girls aged 9-14 years, attending public and private primary schools in Belo Horizonte, Brazil. A multi-stage sampling technique using an equal probability scheme was adopted to select the children. The response rate for the total sample was 97%. Dental examinations were carried out by one dentist (MISC). Intra-examiner agreement was very good. The prevalence of dental injuries increased from 8% at the age of 9 years to 13.6% at 12 and 16.1% at 14 years. Adjusted results showed that children from high socio-economic backgrounds were 1.4 (95% CI = 1.15-1.79) times more likely to present with a dental injury than children with low SES. Boys were 1.7 times (95% CI = 1.41-2.16) more likely to have dental injuries than girls. Children with an overjet size greater than 5.0 mm were 1.37 times (95% CI = 1.06-1.80) more likely to have a dental injury than children with an overjet size equal or lower than 5.0 mm. Finally, children with an adequate lip coverage were 0.56 times (95% CI = 0.44-0.72) less likely to have a traumatic dental injury than those with inadequate lip coverage.