The investigators will be recruiting 12 to 17-year 11-month old patients with a Class II molar relationship,who are presenting for comprehensive orthodontic treatment at the Postgraduate orthodontic clinic at University at Buffalo School of Dental Medicine. Recruited subjects will be randomized into one of 2 groups. Both groups will be receiving a method of Class II correction using the Sagittal First approach, which means the Class II molar relationship will be corrected prior to the leveling and aligning phase of orthodontic treatment. Subjects will be treated using either the Carriere Motion Appliance (CMA), or a sectional appliance fabricated with materials that are commonly found in orthodontic practice. Both appliances will be used according to the CMA guidelines. After Class II correction and removal of appliance, and prior to the next stage of treatment, an additional digital scan of the mouth and a lateral cephalometric radiograph will be taken. Dental and skeletal measurements from initial cephalometric radiographs and models will be subtracted from the corresponding measurements taken on radiographs and models obtained after Class II correction, and comparisons will be made between the two treatment treatment groups. Efficiency will be determined by number of months until Class II molar and canine correction was obtained, and efficacy will be determined by the skeletal and dental measurements obtained.
The sagittal first approach to Class II correction in orthodontic treatment involves correcting the antero-posterior (AP) relationship of the maxillary and mandibular dentition prior to the leveling and aligning phase of orthodontic treatment. The Carriere Motion Appliance (CMA) was made to provide sagittal correction prior to orthodontic treatment with minimal secondary tooth movements that are typically seen with Class II correction. The aim in this study is to explore the efficacy and efficiency of Class II molar correction in adolescent patients using the sagittal first approach with either a sectional, in-office fabricated appliance or the CMA, by measuring total treatment duration (in months) as well as comparing dental and skeletal measurements taken from lateral cephalometric radiographs obtained prior to Class II correction (T0) and immediately after removal of the appliance (T1). The investigators will also be comparing secondary molar and canine rotational movements after Class II correction by comparing digital dental casts obtained at T0 and T1.