两步法单侧整体推磨牙向后方法临床研究

A clinical study of the two-step approach in unilateral maxillary molar bodily distalization

目的介绍两步单侧整体推磨牙向后的方法，并探讨先倾斜、后竖直的矫治理念在推磨牙向后领域的应用。方法选取单侧磨牙远中关系伴同侧牙列中度拥挤的患者12例，男4例，女8例，年龄10-12岁。采用“先倾斜、后竖直”两步推单侧磨牙向远中，矫正Ⅱ类磨牙关系。磨牙颊沟处粘结一条3．5mm长的不锈钢圆丝作为在X线片上观测磨牙运动的标记线。治疗前、后取研究模型、拍摄头颅侧位定位片和全景片并进行测量分析，对测量结果进行配对资料的t检验。结果所有矫治磨牙均达到中性关系，磨牙平均每月远中移动（1．10±0．75）mm，远中倾斜移动阶段平均需要（4．75±1.85）月，磨牙竖直阶段平均（3．56±0．90）月，治疗前后磨牙倾斜角度以及前牙倾斜角度的差异均无统计学意义（P〉0．05）。结论两步法推磨牙向后可以使磨牙达到完全整体后移的效果，且无明显前牙支抗丧失。

Objective To evaluate the clinical outcome of a two-step approach in unilateral maxillary molar bodily distalization. Methods 12 patients with unilateral Class Ⅱ molar relationship in early permanent dentition were selected. A 3. 5 mm signal wire was bonded to the molar buccal groove. Molar distalization by two-step, that was crown inclination first, and then roots upright. Celphalograms and model analyses were carried out before and after treatment. Paired t test was used for statistical analysis. Results Ideal Class Ⅰ molar relationship was achieved. Molar moved 1. 10± 0. 75 mm distally per-month. Inclination and upright periods cost 4. 75±1.85 months and 3.56±0. 90 months respectively. Neither molar nor upper front teeth angle change was significant（P〉0. 05）. Conclusions Such two-step approach provided an efficient way of noncompliance, low anchorage consumption and molar bodily distalization for the orthodontic treatment of patients with Class Ⅱ malocclusion.