三段弓技术与微种植支抗技术压低和内收上切牙效果的对比研究

目的：对比两种不同技术-三段弓技术与微螺钉支抗滑动技术,在正畸治疗过程中产生的牙齿以及骨骼的效应差异。方法：对三段弓技术组的18例患者以及微螺钉支抗组的19例患者均进行切牙的内收和压低,分析测量所有患者的头颅定位侧位片以评估两种技术的差异。在水平和垂直方向上对两组患者上颌第一磨牙的移位和相对骨骼改变进行分析。同时在根尖周X光片上对牙根吸收进行测量。结果：U1-SN（P〈0.05）,覆盖、覆、PP-U1、U1水平移动（P〈0.01）,UL-U1（P〈0.05）,在三段弓组和微螺钉支抗组均有明显减小。然而,在三段弓组,U6角度（P〈0.01）,MP-SN、PP-U6（P〈0.05）和U6水平移动（P〈0.05）,与微螺钉组相比均有显著增加。两组的治疗周期及牙根吸收率无显著性差异。结论：采用反Spee曲线弓丝的微螺钉支抗滑动技术,被证明是有效地的内收并压低上颌前牙的口内支抗增强装置。与三段弓技术相比,微螺钉技术在水平（前后向）或垂直方向均未见支抗丧失。

Comparison of the Simultaneous Intrusion and Retraction Effect on the Maxillary Incisors between Three Pieces Arch Wire Technique and Miniscrew Anchorage

Objective：To compare the dental and skeletal effect of two different techniques,three-piece arch wire technique and miniscrew anchorage sliding mechanics.Methods：Lateral cephalometric radiographs from 18 patients in the three-piece arch wire group and 19 patients in the minscrew anchorage group were analyzed for incisor retraction and intrusion.The upper 1st molar displacement and the relative skeletal changes were analyzed in the horizontal and vertical directions in both groups.Root resorption was also measured on periapical radiographs.Results：Significant reduction of U1-SN（P0.05）,overjet,overbite,PP-U1（P0.01）,U1 horizontal（P0.01）,UL-U1（P0.05） were observed in both groups,the three-piece arch wire group and miniscrew anchorage group.However,there were significant increases in U6 angle（P0.01）,MP-SN,PP-U6（P0.05）,and U6Horizontal（P0.05） in the three-piece arch wire group than in the miniscrew anchorage group（Table IV）.There was no significant difference in the treatment period and root resorption rate between the 2 groups.Conclusion：The miniscrew anchorage sliding mechanics,with Reversed Curved Spee archwire,was proved to be efficient for intraoral anchorage reinforcements for retraction and intrusion of the maxillary anterior teeth.There was no anchorage loss with miniscrew in either horizontal（anteroposterior） or vertical direction compared with three-piece arch wire technique.