关键词: 微种植体支抗, 推磨牙向远中, Nance腭托, 磨牙推进器

Abstract: 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.

Key words: micro-implant anchorage, distal movement of molars, Nance palatal plate, molar propeller