Causes and prevalence of traumatic injuries to the permanent incisors of school children aged 12 years in Jaragua do Sul, Brazil

Aim: To assess the causes and the prevalence of traumatic injuries to the permanent incisors of 12-year-old schoolchildren in Jaragua do Sul, Brazil. Design: Cross-sectional survey. Setting: Public and private primary schools. Participants: 476 children of both sexes, selected by multistage sampling technique. Methods: Clinical examination of upper and lower permanent incisors. Main outcome measures: Incisal overjet, lip coverage, traumatised anterior teeth, cause of trauma. Parents' levels of education and employment status and family income. Results: Boys experienced double the percentage of injuries compared to girls. Children with incisal overjet greater than 5mm (P=0.077) and inadequate lip coverage (P=0.667) were not more likely to have experienced dental injuries. The main causes of injuries to the permanent incisors were falls (26 per cent), traffic accidents (20.5 per cent), sports (19.2 per cent), violence (16.4 per cent) and collisions with people or inanimate objects (6.8 per cent). Socio-economic measures had no significant effect on prevalence of trauma. Conclusions: Policy makers must take the causes of trauma into account when developing a strategy for the prevention of dental injuries. The role of violence in causing traumatic dental injuries has been underestimated.