[Stability of upper molars with the application of implant anchorage].

OBJECTIVE: To investigate the stability of upper molars with the application of micro-screw implant anchorage during orthodontic treatment. METHODS: Fifteen adult patients with severe maxillary protrusion were included. Upper first premolars were extracted and upper posterior anchorage was reinforced with micro-screw implant in all patients. The average treatment period to close the extraction space was 10.5 months. Cephalometric and cast analysis were carried out. RESULTS: During the treatment, the micro-screw implants kept stable in sagittal plane; neither the mesial-distal movement nor the rotation or tipping of the upper molars during the treatment was of statistic significance (P > 0.05); the edge of upper incisors was retracted by 6.99 mm on average, and no significant vertical change was observed (P > 0.05). CONCLUSIONS: Micro-screw implant could provide good anchorage control in the orthodontic treatment.