双阻板磁力矫治器对骨性Ⅲ类错【牙合】畸形的早期治疗效果

Effects of early treatment of class Ⅲ malocclusion with magnetic orthodontic appliance

目的探讨颌间Ⅲ类双阻板磁力矫治器（Class Ⅲ twin-block magnetic orthopedic ap-pliance, TMOA- Ⅲ）早期矫形治疗替牙期及恒牙初期骨性Ⅲ类错骀患者的矫治效果。方法76例患者，男42例，女34例，平均年龄9．1岁，均为上颌后缩造成骨性Ⅲ类错殆畸形，随机分为观察组和对照组，每组各38例，男21例，女17例。观察组佩戴TMOA-Ⅲ5-8个月，平均7．5个月；对照组不佩戴任何矫治器。治疗前后对每例患者行x线头影测量，获取数据进行统计学分析。结果与对照组相比，观察组患者上颌前移明显，长度显著增加（SNA、A-NPg，P〈0．05；PNS-A，P〈0．005），侧貌改善（UL—EL、NsPgs—HL、面凸度，P〈0．005；LL—EL，P〈0．05）。结论对替牙期及恒牙初期上颌后缩为主的骨性Ⅲ类错殆患者，TMOA-Ⅲ可有效促进上颌骨矢状向发育及前移，以改善骨Ⅲ类关系及软组织凹面型，是传统面架前牵引之外可选择的另一种矫治方法。

Objective To develop a Class Ⅲ twin-block magnetic orthopedic appliance （TMOA- Ⅲ ） and to investigate the treatment effects of this appliance on skeletal ClassⅢ malocclusion of mixed dentition and early permanent dentition. Methods The sample consisted of 76 Chinese children （42 males and 34 females, mean age 9.1 years） with Class Ⅲ malocclusion caused by maxillary retrognathism, and the subjects were divided into a treatment group and a control group. The treatment group, 38 subjects （21 males and 17 females）, were instructed to wear TMOA-Ⅲfor 5-8 months （mean 7.5 months） and the control group, 38 subjects （21 males and 17 females）, did not wear any appliance. Cephalometric radiographs were taken and measurement data were used for analysis. Results Compared with the control group, patients of the treatment group showed a favorable increase of maxilla length and anterior movement （PNS-A, P〈0.001; SNA, A-NPg,P〈0.05）, and skeletal Class Ⅲ facial profiles improved （UL-EL, NsPgs-HL, Facial convexity, P 〈 0. 001 ; LL-EL P 〈0.005）. Conclusions The results indicate that TMOA-UI is effective for the treatment of Class Ⅲmalocclusion caused by maxillary retrognathism in mixed dentition and early permanent dentition, which provides another choice for the treatment besides the face mask.