Objective: This study aimed to determine the prevalence of malocclusion and orthodontic treatment need among school-aged children aged 8-14 years living in Bolu, Türkiye, using the Index of Orthodontic Treatment Need (IOTN). Material and Methods: This cross-sectional field study included 601 children with no previous orthodontic treatment, comprising 285 females and 316 males. Intraoral examinations were performed to assess occlusal characteristics, including anterior crossbite, overjet, overbite, crowding, diastema, open bite, and oral habits. Orthodontic treatment need was evaluated using both components of the IOTN: the aesthetic component (AC) and the dental health component (DHC). Sex-related differences were analyzed using the chi-square test. Results: Among the participants, Class I malocclusion was observed in 45.9%, Class II in 45.8%, Class III in 7.5%, and normal occlusion in 0.8%. The prevalence of open bite was 4.0%. Mandibular crowding severity differed significantly between sexes (p=0.021), and open bite was more frequent in females than in males (p=0.019). Malocclusion class distribution also showed a significant sex-related difference (p=0.004), with Class II malocclusion more common in females and Class III malocclusion more common in males. Females had significantly higher AC scores (p=0.001), whereas DHC score distribution did not differ significantly between sexes (p=0.740). No significant sex-related differences were found for anterior crossbite, overjet, or overbite. Conclusion: This school-based community study provides generalizable data on malocclusion prevalence and IOTN-based treatment need. The findings suggest that orthodontic screening should consider sex-related differences and that treatment need may be influenced by both clinical findings and aesthetic perception among children.
İşler et al. (2026) studied this question.