Prevalence of crown fractures in 8–10 years old schoolchildren in Canoas, Brazil The traumas involving anterior teeth are frequently the cause of esthetic and psychologic problems in children and their parents (1, 2). Dental trauma is presently on the increase in dental clinics. This can be verified by all dentists, and with even more frequency among pediatric dentists, being that the traumatic dental lesions appear with more fre- quency among children and adolescents than among adults, because of their exposure to sports and games (3). Besides its importance, there is a small number of evaluations registering the prevalence of children with traumatic lesions in teeth in developing and industrialized countries, principally when compared to epidemiologic data about dental caries and periodontal disease (4). The upper central incisor is the tooth that has been the most affected (5), and coronal fractures are the most prevalent in permanent dentition (6, 7). The type of coronal fracture line that is most common is the oblique, followed by fractures that are horizontal and vertical (8). The portions of dental structures that are most affected are enamel only and fractures involving enamel and dentin (9). The present work evaluated the prevalence of crown fractures in schoolchildren aged 8–10 years, using the parameters of gender, age, affected tooth, number of affected teeth, type of fracture line and affected coronal portion. In addition, the percentage of children that sought out treatment as a result of the dental trauma was also evaluated. Materials and methods This study was part of a survey, in which prevalence of fluorosis and dental trauma in schoolchildren were investigated. The subjects were children from primary school. Two hundred and six students aged 8–10 years were examined (104 girls and 102 boys), from three state public schools in the city of Canoas, Brazil. Its population is 305 711 inhabitants, all living in an urban area. The school selection was made according to the number of registered schoolchildren. From the total population of 4000 schoolchildren aged 8–10 years, a statistical calculation was made to determine an appropriate sample size. The minimum sample size was calculated at 187 children based on a confid- ence interval of 95%. The expected prevalence was 15%. The schools and children included in the study were randomly chosen. Dental Traumatology 2004; 20: 251–254 Printed in Denmark. All rights reserved Copyright Ó Blackwell Munksgaard 2004 DENTAL TRAUMATOLOGY 251 Tovo MF, dos Santos PR, Kramer PF, Feldens CA, Sari GT. Prevalence of crown fractures in 8–10 years old schoolchildren in Canoas, Brazil. Dent Traumatol 2004; 20: 251–254. Ó Blackwell Munksgaard, 2004. Abstract – The objective of this work was to evaluate the prevalence of children with crown fractures in permanent anterior teeth in 206 schoolchildren (104 girls and 102 boys) between the ages of 8 and 10 years, enrolled in three public schools in the city of Canoas, Brazil. The prevalence found was 17% with no significant difference between boys and girls, as well as between the ages. The most affected tooth was the maxillary central incisor, and a majority of the children showed only one affected tooth (88.6%). The types of fracture most commonly found were oblique and horizontal, and the portions of dental structures most affected were ‘enamel only’ and ‘enamel and dentin’. Only seven children (20%) sought out dental treatment. Maximiano Ferreira Tovo, Patricia Roth dos Santos, Paulo Floriani Kramer, Carlos Alberto Feldens, Gilberto Timm Sari Universidade Luterana do Brazil, ULBRA Canoas, Rio Grande do Sul, Brazil Key words: dental trauma; fracture of teeth; epi- demiology Maximiano Ferreira Tovo, Universidade Luterana do Brazil, ULBRA Canoas, Rio Grande do Sul, Brazil Tel.: +55 51 32 33 63 05 Fax: +55 51 32 33 35 77 e-mail: maxftovo@cpovo.net Accepted 21 October, 2003