Abstract:

Objective The purpose of this study was to evaluate curative efficacy of micro-implant anchorage（MIA） and headgear anchorage（HGA） with MBT straight wire appliance in the treatment of class II division 1 malocclusion patients. Methods The study was performed on 40 selected adults making use of MBT with MIA（group A） and with HGA（group B）. We examined the cephalometric and model analysis before and after treatment and compared the curative effect between group A and B.
Results 1）There are significant curative changes in group A and B, such as the overjet, over bite and the position of incisors. These differences have statistic significance. 2）The curative effects are different between group A and B. Except for the Li-E（mm）, most of the values such as SNA（°）, U1-SN（°）, U1-PP（mm）, U6-Ptm（mm）, and OJ（mm） displayed more effective results in group A, and all the differences had statistic meanings. 3）The average period of treatment is shorter in group A（13 months） than in group B（19 months）. 4）In group A, the MIA is less shifted both in the sagittal and vertical direction. And it is kept stabilization under orthodontic force.
Conclusion The better curative efficacy could be get both in the group A and B. There were not only shorter periods of treatment but also better curative effect in the group A than group B.

Key words: Angle class II division 1 malocclusion')">Angle class II division 1 malocclusion, MBT technique, micro-implant anchorage, headgear anchorage