Abstract: Objective To evaluate the efficiency of micro-implant anchorage (MIA) for the treatment of scissors bite on second molars.Methods Nine patients (7 males and 2 females with a mean age of 22.5 years old) of scissors bite on second molars were treated with MIA.CBCT were used to measure and analyze the Dicom data before and after treatment.Results With MIA,the scissors bite on second molars were corrected for a mean course of 4 months.U7j-the sagittal plane distance decreased significantly,and L7j-the sagittal plane distance increased significantly (P<0.05),suggesting the restoration of dental arch width of molars; U7-SN increased significantly,and L7-SN decreased significantly (P<0.05),suggesting that the molar′s axis was restored to normal level.Conclusions MIA could be used as an efficient method to correct scissors bite on second molars; both lock tooth buccal lingual and height abnormalities could be corrected.The course of treatment was short and the efficiency was good.

Key words: scissors bite . , second molar, mini-implants, three-dimensional