بررسی تغییرات عرض قوس در بیماران Class II division 1 درمان شده به روش کشیدن پرمولرهای اول ماگزیلا در مقایسه با روش بدون کشیدن

مجریان: مژگان کچوئی

خلاصه روش اجرا: One of the major issues of concern and debate in orthodontics is the stability of achieved result. The maintenance of inter-molar and inter-canine width has been widely discussed in the literature and is considered to be an important factor in getting stability after treatmentt. Besides, esthetics is one of the main goals of orthodontic treatment. Narrower dental arches in extraction treatment, when compared with non-extraction, have been criticized in previous studies. The aim of this study is to determine maxillary and mandibular arch width changes after orthodontic treatment in Angle Class II division 1 malocclusion subjects, treated either with or without extraction of the maxillary first premolars. This study will be performed using pre and post-treatment study casts of consecutive subjects from the archives of the Department of Orthodontics. Based on 80% power and significance level of 5%, and considering 1.5mm as maximum tolerable error rate and based on standard deviation of 2.5, 45 samples is needed in each group. Patients who were treated either with or without bilateral maxillary first premolars extraction will be included in this study. Dental casts of these patients will be evaluated to determine maxillary and mandibular intercanine and intermolar arch widths. Statistical analysis of the data will be performed using SPSS with paired sample t-test and independent student t-test.