Comparative Study of Maxillary Incisors Apical Root Resorption in Patients with Malocclusion in Vertical Dimension, before and after Fixed Orthodontic Treatment

Apical root resorption 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 for prevention and reduction of complications. The aim of this study was to compare the amounts of apical root resorption in different vertical malocclusion groups before and after fixed orthodontic treatment. In this cross sectional study, the amount of apical root resorption in maxillary incisors in 100 patients (13-18 years old) with class I malocclusion (37 normal bite, 35 deep bite, 28 open bite) were measured through the examination of parallel radiographies (long cone) before and after treatment using photoshop program (software 7.0). Then the groups were compared and analyzed by t-test, One Way ANOVA, Mann-Whitney and Tukey tests. The amount of apical root resorption at central incisors in deep bite groups was significantly greater than normal bite groups (P=0.008) and in normal bite groups insignificantly greater than open bite groups (P=0.013). The amount of apical root resorption at lateral incisors in deep bite groups was significantly greater than open bite groups (P=0.004) and in open bite groups was significantly greater than normal bite groups (P=0.006). The comparison of apical root resorption between deep bite, normal bite and open bite groups indicated that the resorption in deep bite group, in both central and lateral incisors, was more than the other groups.