Methods: In order to evaluate the amount of incisor retroclination, 1 to SN and IMPA angles were assessed in pre and post-treatment lateral cephalograms of 110 patients (55 patients in each treatment group) with Class II malocclusion who had all their 1st premolars extracted as part of orthodontic treatment plan. In order to compare two methods of preadjusted and standard edgewise in achieving correct incisor inclination Chi-square test was utilized.
Results: Difference of pre and post-treatment 1 to SN angle was greater in preadjusted group than in standard edgewise group and this difference was statistically significant. (P= 0.002) Evaluating difference of pre and post treatment IMPA angle did not show any statistically significant difference between treated groups. (P> 0.05)
Conclusions: Preadjusted method causes more retroclination of maxillary incisors but there is no difference between 2 methods of preadjusted and standard edgewise in amount of mandibular incisor retroclination.