Bratteberg M, et al. - A retrospective longitudinal study, including historical clinical data, was conducted to evaluate prevalence, distribution and severity of traumatic dental injuries (TDI) in the permanent dentition of 16-year-old pupils in western Norway. Researchers involved 2055 participants in this analysis. Among Norwegian adolescents, the prevalence of TDI was moderate. It was noted that milder injuries were more frequent than moderate and severe injuries. Risk factors with regard to TDI were age and gender. Data reported that seasonal influence on the occurrence of TDI was not statistically significant.