Objective To evaluate the effect of activator appliance on hard and soft tissue of growing patients who have skeletal Class Ⅱ malocciusion. Methods Pretreatment and posttreatment cephalometric records of 30 consecutively treated Patients with Class Ⅱ malocclusions were evaluated and compared with 20 volunteers of untreated Class Ⅱ control subjects. Lateral cephalometric and study models were taken at the beginning and the end of the treatment. Paired t tests were used to assess differences in the rates of change of the different variables in the treatment and control groups. Results The changes of SNA, SNB, ANB, Go-Gn, Ar-Go, S-Go, N-Me between two groups have statistically significance, the mandible horizontal growth became normal. Conclusion Activator appliance treating skeletal ClassⅡmalocclusion in growing patients not only inhibit maxillary growth and reduce the maxillary protrusion, but also promote the mandible growth.
