Research Article Prevalence of Orthodontic Treatment Need and Occlusal Traits in Schoolchildren Abdolreza Jamilian, 1 Alireza Darnahal, 2 Elnaz Damani, 2 Maziar Talaeipour, 3 and Zinat Kamali 4 1 Fellow of Orthognathic Surgery, Department of Orthodontics, Center of Craniofacial Research, Islamic Azad University, Dental Branch, No. 2713, Vali Asr Street, Tehran 1966843133, Iran 2 Department of Orthodontics, Islamic Azad University, Dental Branch, Tehran 1946853314, Iran 3 Department of Periodontics, Islamic Azad University, Dental Branch, Tehran 1946853314, Iran 4 National Nutrition and Food Technology Research Institute, Faculty of Nutrition Sciences and Food Technology, Shahid Beheshti University of Medical Sciences, Tehran 1985717443, Iran Correspondence should be addressed to Abdolreza Jamilian; info@jamilian.net Received 22 May 2014; Revised 28 July 2014; Accepted 18 August 2014; Published 29 October 2014 Academic Editor: Paul C. Dechow Copyright © 2014 Abdolreza Jamilian et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background. Widespread use of the IOTN along with detailed study of occlusal traits is suitable for planning community dental health resources. Objectives. he aim of current study was to assess the need for orthodontic treatment among school children of Tehran by means of the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN) and also to evaluate the occlusal traits of the subjects. Methods. 684 (343 boys and 341 girls) school children, 15 to 17 years of age, were selected at random from 12 schools to represent the four main areas of Tehran. he inal sample who met the inclusion criteria comprised 643 subjects (322 males and 321 females). Malocclusion was determined with the Index of Orthodontic Treatment Need. he IOTN grades were statistically compared in the two genders using chi-square test. Results. Orthodontic treatment need, using the DHC, was found in only 9.0 per cent of the children. he prevalence of Angle Class I malocclusion in this study was higher than other malocclusions (65.2 per cent), followed by crowding in 62.7 per cent of the subjects. Conclusion. Orthodontic treatment need for Tehran high school students was relatively lower than that reported in most recent studies in Europe. 1. Introduction Malocclusion in itself is neither a disease nor a life threatening condition [1]; nevertheless, the appearance of the mouth and smile plays a signiicant role in judgments regarding facial attractiveness. hus, malocclusion has large physical, social, and psychological impact on the individual and society [2, 3]. Several studies have attempted to provide epidemiological reports of the prevalence of malocclusions in diferent ethnic groups [4–6]. In the last four decades scientists have proposed several indices for scoring how much the teeth deviate from the normal, as indicators of orthodontic treatment need. Grainger’s Treatment Priority Index (TPI) [7] which was proposed in 1960s can be named as one of the most prominent ones since it was widely used in the 1965–1970 US population surveys. Recently, the Index of Treatment Need (IOTN) was proposed by Brook and Shaw [8] in the United Kingdom as a scoring system for estimating treatment need of patients with various degrees of malocclusion. his index places patients in ive grades from “no need for treatment” to “extreme treatment need” (Table 1). A few investigations have evaluated the prevalence of malocclusion in Tehran, but none of these investigations studied the details of malocclusions. herefore, the purpose of the present epidemiologic study was to evaluate the orthodontic variables of 15–17 year-old schoolchildren in Tehran by means of the IOTN. 2. Material and Methods his study received approval from the Human Research Ethics Committee of IAU of Medical Sciences. Twelve schools Hindawi Publishing Corporation International Scholarly Research Notices Volume 2014, Article ID 349793, 5 pages http://dx.doi.org/10.1155/2014/349793