We aim to assess the treatment outcomes following upper incisors retraction accelerated by corticotomy procedure. So, we intend to randomize orthodontic patients with class II division I malocclusion into two groups: experimental group and control group. Both groups will start orthodontic treatment. Once a 0.019*0.025-inch stainless steel wire is fully engaged to the brackets, 1st premolars will be extracted. Canines will be retracted in the conventional manner. Then, the actual evaluation period starts when the upper incisors are retracted using two different methods.