Abstract:

  Background and Aim: 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 2^nd-5^th grade children of primary schools in Rasht in year 2007.

  Materials and Methods: For this descriptive, cross-sectional study1042, 2^nd - 5^th grade 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.

  Results: Prevalence of crown fracture in anterior teeth was 15.2%. The ratio v male to female patients 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.

  Conclusion: There was a tendency for children with an increased over jet and deep bite to have more dental injuries.

 Key words: Prevalence, Crown, Tooth Fractures.