种植体支抗对高角拔牙病例垂直向控制的颌（牙合）面改变

Craniofacial changes of high angle extraction cases treated with posterior vertical control through implant anchorage

目的探索以微螺钉种植体支抗压低磨牙对高角拔牙病例进行后牙垂直向控制的临床应用。方法20例矢状骨面型Ⅰ类或Ⅱ类的高角拔牙病例，采用MBT直丝弓矫治技术，于第一、第二磨牙间颊侧植入MAS微螺钉种植体作为垂直向支抗对磨牙实施持续轻力压低，同时微螺钉也作为矢状向支抗结合滑动法回收前牙。结果治疗后X线头影测量分析结果显示：上颌磨牙平均压低2．27mm; MP／SN角平均减小2．8°，SNPo角平均增加1．34°；面角（NsPos／FH）角平均增加3．18°；差异均有统计学意义（P〈0．001）。结论微螺钉种植体支抗压低磨牙能够为高角拔牙病例提供有效的后牙垂直向控制，患者软组织侧貌显著改善。

Objective To explore the clinical application of posterior vertical control of high angle extraction cases through molar intrusion by microscrew implant anchorage. Methods 20 patients with high mandibular plane angle and Class Ⅰ or Ⅱ skeletal relationships were selected for the current study, all of them had been treated with extraction and MBT straight wire technique. MAS microscrews were implanted in the buccal alveolar bone between the 1st and 2nd molars, posterior vertical control was carried out through molar intrusion by microserew implant anchorage, and microscrews were also used as the maximum anchorage for space closure through sliding mechanics. Results Cephalometric analysis for treatment results showed that upper molars were intruded by 2.27 mm in average; MP/SN angle decreased by 2.8° and SNPo angle increased by 1.34° in average; NsPos/FH angle increased by 3. 18° respectively in average, significant differences （P〈0. 001）were found in all the changes. Conclusions Microserew implant anchorage can provide effective posterior vertical control for high angle extraction cases through molar intrusion, patients＇ facial profile had been improved greatly.