Abstract: Objective To evaluate the effects of microimplant anchorage combined with casting appliance on the intrusion of extruded upper second molars. Methods The 8 cases were 24-52 years old. They had lost one lower second molar for a long time, which resulted in protruded upper second molars and no space for restoration. Micro-implants were used as absolute anchorage and casting appliances as the force transmission system. The power chain was the tool to intrude prolonged molars. Results The average intrusion of the eight cases was 3.2 mm. The achieved vertical space was enough for the restoration. Denture restoration was completed. The average treatment period was 5 months. There was no obvious root resorption、pulp necrosis and teeth loosening. Conclusion Combination of microimplant anchorage and casting appliance is a useful force system to intrude protruded upper second molars.