Comparison of the Rate of Maxillary Incisors Apical Root Resorption in 13-18 Years old Patients with Cl I, Cl II and Cl III Malocclusions, before and after Fixed Orthodontic Treatment

Statement of Problem: Apical root resortpion of maxillary incisors is relatively a common phenomenon at the end of orthodontic treatment. Therefore, recognizing risk factors in root resorption before starting the treatment is very important. The aim of this study was to compare the amounts of apical root resorption in different malocclusion groups. The amount of apical root resorption in 219 fixed orthodontic (70 Cl 1, 76 Cl II and 73 Cl III patients) with first or second maxillary premolars extraction and with mean age of 15±0.5 years were evaluated through the examination of parallel radiographies (long cone) before and after treatment. The amount of apical root resorption was measured in groups by using Photoshop program (Version 7.0). Then, the groups were compared and analyzed by t-test and one way ANOVA. One hundred percent of patients (84.96% of teeth) showed first degree resorption, 18%, zero degree resorption; 1.37%, third degree and 12.8% showed second degree resorption. The greater resorption of second degree was observed in Cl II patients. Left and right incisors and central and lateral incisors had no significant differences among all the three groups. The comparison between apical root resorption in CI, Cl II and Cl III groups indicated that the resorption in Cl II group was more than Cl I and Cl III groups (p<0.001).