Dentoskeletal and soft-tissue changes concurrent to use of PowerScope appliance in treatment of Class II malocclusion – A retrospective study

The most frequently encountered malocclusion in our daily clinical practice is Class II malocclusion with mandibular retrognathism. Treatment modalities for Class II malocclusion correction depend on numerous factors such as the severity of the malocclusion and the age at which the patient reports for the treatment. One of the innovations in Class II treatment is the PowerScope appliance. The objectives of this study were: (1) To evaluate dentoskeletal changes with the use of PowerScope appliance in the treatment of Class II division I malocclusion using lateral cephalograms in late adolescents. (2) To evaluate the soft-tissue changes with the use of PowerScope appliance in the treatment of Class II division I malocclusion using lateral cephalograms in late adolescents. This retrospective and cross-sectional study was done using pre- and post-treatment lateral cephalograms of 15 patients treated with PowerScope appliance who were under decelerated growth phase as assessed by cervical vertebrae maturation index (Stages 4, 5, and 6). All the lateral cephalograms were hand traced and measured by same investigator. A highly statistically significant difference was observed between the pre-and post-angle formed by sella nasion plane and nasion to point B line (SNB), angle formed by nasion to point A line and nasion to point B line (ANB), condylion to point gnathion (Co–Gn), and distance between point A to nasion perpendicular (N perpendicular to Point A) to Pog skeletal parameters. It was found that a highly significant difference was noted for parameters upper molar to palatal plane (U6-PP), lower incisor to nasion to point B line (L1-NB), lower incisor to nasion to point B line (L1-NB*), lower incisor to mandibular plane angle (IMPA), and upper molar to pterygoid vertical line (U6-PTV). A significant difference was present for parameters upper incisor to nasion to point A line (U1-NA), while no difference was observed for upper incisor to sella nasion plane (U1-SN) and upper molar to pterygoid vertical line (U6-PTV). A significant statistical difference was observed between the pre-and post-lower lip to E line parameter. PowerScope caused significant skeletal changes by forward repositioning of the mandible as well as by an increase in the length of the mandible. There was significant retrusion of upper incisors and a highly significant increase in lower incisor protrusion, lower molar mesialization, and upper molar intrusion. Soft-tissue lower lip protrusion was significant.