口内上颌前方牵引器治疗安氏Ⅲ类错[牙合]的临床研究

Clinical study of application of intra-oral maxillary protractor in treatment of Class Ⅲ malocclusion

目的应用口内上颌前方牵引器辅助治疗安氏Ⅲ类错[牙合]畸形，并与传统的面具式上颌前方牵引进行对比，以探讨口内前方牵引器在安氏Ⅲ类患者早期矫形治疗中的作用。方法选择20名安氏Ⅲ类患者，首先戴用上颌扩弓器以周期性扩缩方式行快速扩弓7周，然后将患者分为2组。组1（10人）戴用牙支持式口内前方牵引器直至前牙反[牙合]解除，继以夜间戴用面具式前方牵引；组2（10人）直接戴用上颌前方牵引面具，要求每天至少戴用14小时。平均观察10个月。结果两组患者治疗后ANB和覆盖均有明显改善，且口内前方牵引器治疗组较单纯面具式前方牵引组改善程度为著（P〈0．05）。反[牙合]解除时间组1（平均2．3个月）较组2（平均7．8个月）显著为快（P〈0．001）。结论辅助应用口内前方牵引器能有效地矫形治疗骨性安氏Ⅲ类错[牙合]。

Objective The aim of this study was to evaluate the skeletal and dentoalveolar changes achieved by a tooth-borne maxillary protractor in growing skeletal and dental Class Ⅲ patients and to compare these changes with maxillary protraction face mask group. Methods Twenty patients were selected and treated with repetitive rapid palatal expansion and constriction for 7 weeks. The patients were divided into two groups according to the treatment type： the intra-oral protractor group （mean age 10. 12±1. 81 years, n = 10） and the Delaire type maxillary protraction group （mean age 11.02±1.08 years, n= 10）. In group one a tooth-borne maxillary protractor was used until anterior crossbite was corrected and then followed by wearing face mask protraction at night time. In group two, maxillary protraction face mask was required to wear at least 14 hours/day. Results Significant changes in ANB and overjet were noted in the both groups and demonstrated the effects of the appliances in the treatment of Class Ⅲ malocclusions. In comparing the two groups, the improvements were greater in the intra-oral protractor group （P〈0. 05）. The duration for the correction of crossbite was reduced significantly in group one （2.3 months on average） than that in group two （8. 6 months on average, P〈0. 001）. Conclusions The combination use of an intra-oral protractor is effective for correction of skeletal Class Ⅲ malocclusion.