微种植体与J钩内收上前牙后的切牙位置变化比较

Comparative study of the changes of upper incisor positions of retraction treament with microimplant and J hook

目的比较微种植体支抗和头帽J钩内收上前牙后上颌切牙及支抗磨牙位置变化的差异。方法选择24例安氏Ⅱ1上颌前突患者,随机分为微种植体组和J钩组各12例,微种植体组在上颌第二前磨牙和第一磨牙牙根间植入微种植体支抗,内收上前牙,J钩组使用头帽J钩内收上前牙,比较两种支抗方式矫治前后X线头影测量的变化。结果矫治后,两组上中切牙切缘至RL距离以及上中切牙角均减小,微种植体组减少更明显,上切牙内收且直立,差异具有统计学意义(P<0.05);两组上中切牙切缘至腭平面距离均减小,上切牙被压低,J钩组压低更显著,两组间比较差异具有统计学意义(P<0.05);J钩组上磨牙至RL距离、腭平面距离明显增大,上磨牙近中移动、伸长,微种植体组增大不明显,两组间比较差异具有统计学意义(P<0.05)。结论微种植体支抗内收上颌切牙效果显著,支抗磨牙前移较少,是稳定有效的骨性支抗,但植入在牙槽骨后段的微种植体压低上前牙的作用却不及头帽J钩,严重的深覆深覆盖应考虑两种支抗方式的联合应用。

Objective To observe the position changes of upper incisor and molar using microimplant and J hook to retract anterior teeth, and to analyze the discrepancy of two kinds of anchorage reinforcement. Methods Twenty-four patients with class Ⅱ1were randomly divided into two groups: microimplant group and J hook group(n=12). Microimplants were implanted in the interdental bone between the roots of the maxillary first molar and second premolar for retraction in microimplant group, while headgear J hooks were used in J hook group. Cephalometric analysis was taken before and after orthodontic treatment. Results U1E-RL and U1-SN°of each group after treatment were decreased, and the decrease was more significant in microimplant group than J hook(P<0.05). The upper incisor was retracted effectively and uprighted in microimplant group, and U1E-PP in J hook group fell more than microimplant group(P<0.05). The obvious intrusion of upper incisor was observed in J hook group. U6S-RL, U6A-RL, U6S-PP and U6A-PP were increased significantly in J hook group, and the upper first molar was moved mesially and occlusally. While in microimplant group, the upper first molar had no significant changes and there were statistical differences between the two groups(P<0.05).Conclusion Microimplant is an efficient and stable anchorage to retract anterior teeth and control molar movement. However, J hook has an advantage over microimplant implanted posterior in anterior teeth intrusion. The combination of microimplant and J hook could be a more efficient mean to treat patients with severe anterior deep overbite and jet.