OBJECTIVETo investigate the effects using mini-plate implant as anchorage for maxillary protraction in skeletal Class III malocclusion with retruded maxilla.

METHODSTotally 8 skeletal Class III patients aged 11 - 14 years were included in this study. There were 4 males and 4 females. The mini-plate implants were placed between the upper lateral incisors and canines on both sides in each patient. The mask was used after 1 month healing following mini-plate implant surgery. Cephalography and panoramic radiographs were taken for each patient before and after protraction. Twenty-one cephalometric measurements were used for assessment. Statistically, paired t-test was used.

RESULTSAfter protraction, SNA, ANB, Wits, NA-PA, Max-Lth, A-NP distances increased and the significant difference was founded (P < 0.01). ANS-Me, Is-FHp, Ms-FHp, A-FHp distances increased significantly, too (P < 0.05). L1-AP, OJ, AB-NP decreased and the significant difference was detected (P < 0.05). The changes of SNB, MP-SN, PP-SN, U1-PP, U1-SN, U1-AP, L1-MP and ANS-Me/N-Me ratio were not significant (P > 0.05).

CONCLUSIONSMini-plate implant was an effective and stable anchorage for promoting forward growth of maxilla following maxillary protraction.