Clinical study on lower anterior teeth intrusion with miniscrews implanted in extra-alveolar mental symphysis
Objective To investigate the effectiveness of the lower anterior teeth intrusion with minis-crews implanted in extra-alveolar mental symphysis.Methods 18 cases(11 males and 7 females)of anterior deep overbite(class Ⅲ)caused by extrusion of the lower anterior teeth were selected,and two miniscrews parallel to the tooth axis were implanted in extra-alveolar mental symphysis.The intrusion force was applied from the distal ex-tension arm attached to the miniscrew.If necessary,the distal force was applied concurrently to control the torque of the anterior teeth.Analyzing the position changes of the lower anterior teeth was based on the voxel overlap of pre and post-treatment CBCT imaging data.Paired t-test was conducted on the data before and after treatment with the Graphpad Prism 6.0 software package,and P＜0.05 was considered as a significant difference.Results All the lower anterior teeth were effectively intruded,L1-MP and LCR-MP were significantly reduced,the spee's curve was flattened(P＜0.05),and the anterior deep overbite was improved significantly.IMPA was increased without statistically difference,the root length did not show any significant change either.Conclusion The miniscrews implanted in extra-alveolar mental symphysis can provide effective force system to achieve absolute intrusion of the lower anterior teeth.
Mental symphysisMiniscrewsIntegrated force applicationAbsolute intrusion
万方数据
维普
