Comparison of double-plate appliance/facemask combination and facemask therapy in treating class III malocclusions.

OBJECTIVE: To compare the treatment effects of double-plate appliance/facemask (DPA-FM) combined therapy and facemask (FM) therapy in treating Class III malocclusions. MATERIALS AND METHODS: The material consisted of lateral cephalometric radiographs of 45 children with skeletal and dental Class III malocclusion. The first treatment group comprised 15 patients (mean age = 11 years) treated with FM. The second treatment group comprised 15 patients (mean age = 10 years 9 months) treated with DPA-FM. The third group comprised 15 patients (mean age = 10 years 5 months) used as controls. The paired t-test was used to evaluate the treatment effects and changes during the treatment and observation period in each group. Differences between the groups were determined by variance analysis and the Duncan test. RESULTS: With the DPA-FM and FM appliances, the SNA and ANB angles increased significantly. These changes were statistically different compared with the control group. Lower facial height showed a greater increase in both treatment groups than in the control group. Molar relation showed a greater increase in the DPA-FM group than in the FM group. The increase in U6/ANS-PNS angle in the FM group was significantly different from the DPA-FM and control groups. The L1/NB angle and Pg-T increased significantly only in the FM group, but no significant difference was found between the treatment groups. CONCLUSIONS: In the treatment of Class III malocclusion, both appliances were effective. The significant sagittal changes in the lower incisors and pogonion in the FM group compared with the nonsignificant changes in the DPA-FM group might be due to the restriction effect of acrylic blocks in the DPA-FM group.