ABSTRACT
Regarding to the importance of anterior permanent teeth in mastication, speaking and esthetic, also high prevalence of crown fracture due to traumatic injuries of the permanent teeth, this study was designed to evaluate the etiology and prevalence of crown fracture of anterior permanent teeth in 2nd-5th grade children of primary schools in Rasht, in year 2007.For this descriptive, cross-sectional study 1042, 2nd-5thgrade students were selected from 10 randomly chosen primary schools in Rasht. Examination was carried out by flash light. Information in regard to age, gender, type of crown fracture, tooth number, amount of over jet, overbite, lip seal, etiology of trauma and performed treatments following trauma were recorded. The data were analyzed with SPSS software and Chi-Square test. Prevalence of crown fracture in anterior teeth was 15.2%. The male to female ratio was 1.7/1.Maxillary central incisors were the most affected [53.5%] and the most common type of crown injury was enamel fracture [80.3%]. Most of injuries had occurred at home [49%] and during summer [40.8%]. Falls and foreign bodies striking were the most frequent cause of dental traumatic injuries. There was a tendency for children with an increased over jet and deep bite to have more dental injuries