Objective To evaluate the efficiency of micro- implant anchorage（MIA） for posterior teeth intruded and the result of the treatment of scissors bite on one- side posterior teeth. Methods The study included 3 females and 1 male. All the overextruding upper posterior teeth were intruded by the MIA. The micro- implant screws were inserted into the buccal and lingual alveolar bone of the maxillary posterior teeth or the buccal alveolar bone of mandibular posterior teeth. About 0.833 N force was used to intrude the overgrowthing upper posterior teeth, and about 0.559 N force was used to draw buccally the low posterior teeth tilting lingually. Results The overextruding upper posterior teeth were intruded 2.0 mm on average, the low posterior teeth tilting lingually were upreared buccally. All the MIA screws kept stable during the treatment, but there was a slight inflammation around the implant screws. Conclusion MIA could be used as an efficient method to correct scissors bite on one- side posterior teeth with intruding overgrowth upper posterior teeth, or uprearing buccally the tilting low posterior teeth.
