Efficacy of Mandibular protraction appliance IV versus PowerScope in treatment of class II malocclusion; A comparative, randomized clinical trial

Objective: To evaluate and compare the efficacy of Mandibular protraction appliance IV (MPA-IV) and PowerScope (PS) in the treatment of skeletal Class II malocclusion patients. Subjects and methods : A total of 16 circumpubertal class II patients (ANB°>4°) with mandibular deficiency were randomly divided equally into two groups; group 1: treated by MPA-IV, their mean age was 14.98 ± 1.33 years, group 2: treated by PS appliance (American Orthodontics, Sheboygan, Wis), their mean age was 14.67 ± 1.37 years. In both groups, fixed functional appliances were installed for six months. Treatment outcomes were assessed by cephalograms taken immediately pre-and post-functional appliances therapy. Results : Intergroup comparisons of the mean treatment changes revealed significant improvements (P ≤ .05) in SNB°, SN-Pog°, Ar-Go-Me°, Co-Gn mm, B-Sv mm, Pog-Sv mm, S-Go mm, and lower lip advancement (Li-Sv mm and Pog’-Sv mm) in MPA-IV group. While in the PS group, there were significant greater decrease of SNA° and upper incisors retraction (P ≤ .05). Conclusion: Both appliances could be used efficiently in the treatment of class II malocclusion. MPA-IV produces superior mandibular advancement and lower lip projection, while the effects of PS are mainly dentoalveolar changes.