Objectives: The study was to investigate the effects using miniplate implant as anchorage for maxillary protraction in Skeletal Class III malocclusion with retruded maxilla.

Methods: Totally 9 patients with Skeletal Class III malocclusion were included in this study, in which 5 are females, and 4 are males. They are aged from 11 to 14 years old, and 11.8 years in average. The miniplate implant were placed between the upper lateral incisors and canines on both sides in each patient. The facemask was used after 1 month healing following miniplate implant surgery, and 450 grams force was performed for maxillary protraction on each side. Treatment duration was from 6 to 12 months, and 8 months in average. The lateral head film of each patient was taken before and after protraction, and cephalometric analysis was used for assessment. Statistically, paired t-test was used.  

 Results: After protraction, SNA angle increased by 4.04 degrees (from 77.06 to 81.11 degrees in average), and ANB angle decreased by 3.45 degrees (from –4.90 to –1.45 degrees in average) The significant difference were founded ( P<0.001). While, SNB angle increased by 0.59 degrees (from 81.97 to 82.56 degrees in average), but no significant difference was detected (P=0.56>0.5). U1PP angle increased by 0.02 degree (from 123.97 to 123.99 degrees in average), and no significant difference was detected (P=0.99>0.05). L1MP angle decreased by 1.52 degrees (from 85.99 to 84.47 degrees in average), but no significant difference was found ( P=0.5>0.05).

Conclusion: The result showed us that miniplate implant is good anchorage for promoting forward growth of maxilla with less dental effect following maxillary protraction.