Aim: The main goal of thisstudywas to evaluate orthodontic treatment needs (IOTN) ofschoolboys population of Isfahan in 2009-2010based on Index of Orthodontic Treatment Need (IOTN).
Materials and Methods: In this study an examiner used the Dental Health Component (DHC) and Aesthetic components (AC) of IOTN to assess Orthodontic treatment needs for 400 Isfahan schoolboys. Multistage randomized cluster sampling method was used to choose the participants. All the participants were schoolboys aged 11 to 14 years. Using the IOTN, Malocclusion was determined. To evaluate the data a chi-square test was carried out.
Results: Taking into account DHC, 3.5% of Isfahan schoolboys were in 'Extreme need', 14% in 'Severe need', 25% in 'Moderate need', 38.5% in 'Little need' and 19% had 'No need' to orthodontic treatment.In evaluating AC, 77.5% had no need or little need, 16.5% had moderate need and 6% had great need to treatment group.
Conclusion: It was concluded that 17.5% of 11-14 year-old male students in Isfahan need orthodontic treatment (IOTN grades 4 and 5) and common deviations in this group were impaction, hypodontia and contact displacement.