Abstract: Objective To provide enough interarch distance for implant restoration of jaw missing teeth by implanting miniscrew as anchorage, combined with orthodontic pressure, and intruding excessive growth maxillary molars．Methods Eleven adult cases with fifteen excessive growth maxillary molars were admitted in this study, and the reduced interarch distance was not adequate for implanting mandible molars. Two self-tapping miniscrews were implanted as anchorage in the buccal and palatal bone of the excessive growth maxillary molars. The force was applied immediately and was replaced every four weeks until the interarch distance was adequate. The changes of length were observed before and after the treatment by CBCT images. Results All fifteen excessive growth maxillary molars were intruded effectively with the average distance of 2.49 mm and the average duration of 5.8 months. There were no remarkable changes in tooth mobility before and after the treatment. Conclusion The miniscrew as orthodontic anchorage is available for intruding excessive growth maxillary molars.

Key words: miniscrew, excessive growth maxillary molars, CBCT