微种植体支抗推磨牙向远中移动的临床应用

目的 评价2种推磨牙向远中移动支抗装置的临床疗效。方法 选择30例因上颌磨牙前移所致的安氏Ⅱ类错牙合畸形患者，随机分为2组：微种植体支抗结合磨牙推进器组（A组）和Nance腭托支抗结合磨牙推进器组（B组）。对矫治开始之前与磨牙远移到位后的头颅定位侧位片以及磨牙远移速率进行比较，评价磨牙远移后颅面硬组织变化的结果。结果 A组与B组治疗前后SNA、SNB、ANB值变化量均无明显差异；B组U1-NA、U1-SN值在治疗前后变化量均较A组大；2组在磨牙移动距离上无明显差异(P>0.05)；但A组月平均移动速率明显大于B组。结论 初步临床观察表明应用微种植体支抗推磨牙向远中移动能更好地控制支抗，移动速率快，异物感小，易清洁，治疗效果更佳。

Clinical application of molar distalization by micro implant anchorage

Objective To evaluate the effect of two anchorage devices on molar distal movement． Methods Thirty patients with Angle class Ⅱ malocclusion because of antedisplacement of maxillary molars were randomly divided into two groups:micro implant anchorage combined with molar propeller group (group A) and Nance palatal holding arch combined with molar propeller group (group B).To compare cephalometric lateral radiographs before treatment and after molar distalization in place,The results of changes in craniofacial hard tissue after molar distalization were evaluated. Results Changes in SNA、SNB、ANB in two groups had no significant difference before and after treatment.Changes in U1-NA,U1-SN in group B were bigger than those of group A before and after the treatment.Two groups had no significant difference in moving distances of molars (P>0.05).However,the monthly average rate of movement in group A was significantly higher than that of group B. Conclusions Preliminary clinical observation shows that the application of micro implant anchorage for distal movement of molars can control the anchorage better.It has higher moving speed causes little foreign body sensation,and it′s easy to clean,and it leads to better treatment result.