固定磨牙远移装置与活动推磨牙向后装置的临床对比研究

Contrast study of removable appliance and modified rapid helix expansion appliance

目的：评价两种后推磨牙矫治器的主要优缺点。方法：将29例磨牙前移所致的Ⅱ类错颌分成两组，应用两种完全不同的后推装置进行矫治：①活动法采用口内常规活动矫治器推磨牙向后；②固定法采用自制的固定矫治器，应用NiTi推簧推磨牙向远中。结果：活动法需6．3～9．1个月可达到预期效果，但需要患者高度配合，磨牙远移以倾斜移动为主；固定法需1～3．1个月就达到目标，且磨牙以整体移动为主。结论：两种方法均能达到磨牙向远中的预期效果，但活动法疗程长，牙体位倾斜移动，依从性高；固定法疗程短，磨牙以整体向远中移动。

Objective To evaluate the advantages and disadvantages of two types of appliances for maxillary molar distalization. Method Total 29 patients with class 11 malocclusion resulting ,from molars shifting mesially were treated with two different molar distalization methods as removable and fixed appliances. An intra -oral removable acrylic appliance was used to distraction. The modified rapid helix expansion appliance （MRHEA） made the maxillary first molar distalization by using NiTi push - reed. Results The desired efforts were gained in 6.3 - 9.1 months by using removable appliances, but duly 1 - 3.1 months hy using MZHEA. The treatment results of using removable appliances were depended on patients＇cooperation, however, the method of using appliance overcame some shortcomings of other molar distalization techniques, and this appliance would not lead to distal inclination of the crown of the shifted teeth. Conclusion The two methods can convert molar distalization. The MRHEA can save much chairside time, and shorten the period of treatment, move molars distally parallel.