应用鞋拔曲近中移动下颌第二磨牙的临床研究

Clinical observation of shoehom loop in the mesial movement of mandibular second molars

目的探讨应用鞋拔曲近中移动下颌第二磨牙的临床效果。方法选择22例下颌第一磨牙严重龋坏的错牙合畸形患者,随机平均分为2组,均拔除2颗下颌第一磨牙,均采用MBT直丝弓矫治器矫治,排齐整平牙弓后,试验组11例患者采用鞋拔曲近中移动下颌第二磨牙,对照组11例患者采用不锈钢平直方弓丝近中移动下颌第二磨牙,对两组下颌第二磨牙近中移动前后的X线头颅侧位片和研究模型进行测量和统计学分析。结果 2组的L7-MP角、L7轴角和L7支抗强度在下颌第二磨牙近中移动的差值差异有统计学意义(P<0.05);其他测量项目差异均无统计学意义(P>0.05)。结论应用鞋拔曲近中移动下颌第二磨牙临床效果良好,有一定的临床实用价值。

Objective To evaluate the clinical effects and the advantages of shoehom loop in the mesial movement of mandibular second molars. Methods Twenty-two patients with unhealthy first molars were selected, and randomly di-vided into two groups according to the use of shoehorn loop or not. All of them had been treated with extraction of mandib- ular first molars and MBT straight wire technique. The differences of cephalometric analysis and model analysis between the pre and post-treatment periods were analyzed to evaluate the changes occurring as a result of orthodontic treatment. Results Compared with control group, these was significant difference of L7-MP, mesio-palatal rotation and anchorage of mandibular second molars in experimental group （ P 〈 0. 05 ）. The difference of other parameters was not statistically significant （P 〉 0.05 ）. Conclusion The clinical effect of shoehorn loop was stable and efficient. Shoehom loop could provide effective control in the mesial movement of mandibular second molar.