Abstract: Objective To assess the use of microimplants in the retromolar area for the uprighting treatment of mesial impacted mandibular second molars. Methods　 To select thirteen patients in the year of 2011-2014 who have mesial impacted mandibular second molar in Department of Orthodontics,Jiangsu Province Stomatology Hospital. Twenty-three impacted mandibular second molars were treated with the retromolar placement of a microimplant. Crowns of impacted molars were moved occlusally and distally. Results　All of the twenty-three impacted mandibular second molars were uprighted and brought into occlusion.The average treatment period was 6.5 months. Conclusions　 A microimplant as anchorage in the retromolar area is a more simple and effective application of force to upright the impacted molar. It will facilitate vertical control during the uprighting phase of treatment and avoid adverse effects to the adjacent teeth.

Key words: microimplant, uprighting, mesial impacted mandibular second molar