Effects of micro-implant anchorage on tooth movement in orthodontics by multi-slice spiral CT

Objective To investigate the position changes of the upper molars,incisors and lower incisors with the application of microscrew implant anchorage during orthodontic treatment.Methods Twenty patients with severe maxillary protrusion were selected according to the selection criteria and randomly divided into 2 groups,including micro-implant anchorage group and traditional orthodontic anchorage group.The upper and lower first premolars were extracted in both groups and multi-slice spiral CT was applied for the micro-implant anchorage group to examine the bone for micro-implant.Cephalometric measurements before and after the treatment were performed to evaluate the clinical outcomes.Results During the treatment,93% of the micro-screw implants was stable in sagittal planes.There were significant differences in the positional changes of upper incisors edge and molars between micro-implant anchorage group and traditional orthodontic anchorage group during the treatment(P0.05).There was no significant difference in the lower incisors edge(P0.05).Conclusion Micro-screw implant could provide good anchorage in the orthodontic treatment.