基于颈椎骨龄定量分期法的上颌发育不足患者最佳矫形时机的探讨

The Optimal Treatment Timing for Maxillary Skeletal Retrusion Based on Quantitative Cervical Vertebral Maturation

目的基于颈椎骨龄定量分期法(quantitative cervical vertebral maturation,QCVM),探讨上颌发育不足的Ⅲ类错畸形的最佳矫形治疗时机。方法随机选择2007年12月至2011年10月期间在华中科技大学同济医学院附属协和医院口腔正畸科就诊的上颌发育不足、表现为Ⅲ类错畸形的患者,根据陈莉莉、林久祥等研制的颈椎骨龄定量分期法,双盲法将患者分为4期:QCVM第Ⅰ期(加速期)、QCVM第Ⅱ期(高峰期)、QCVM第Ⅲ期(减速期)、QCVM第Ⅳ期(结束期),每期30例共120例患者入选,年龄8.5～15.6岁(平均年龄12.5岁,其中男性68例,女性52例)。分别利用正畸前牵引面具对4组患者上颌骨前牵,解除面中部凹陷和前牙反,疗程约6个月。然后对患者治疗前后的头影测量X线片进行比较,观察在QCVM 4期中各个阶段的患者上颌骨骨骼参数的变化,利用t检验对各组治疗前后的参数变化进行统计学分析。结果上颌矢状方向的变化显示:在QCVMⅠ期、Ⅱ期和Ⅲ期SNA、A-N perp、Co-A、ANB、颌凸角、Wits、ANS-PNS⊥SN’等矢状向参数在治疗前后有显著性变化;上颌垂直方向的变化显示:在QCVMⅠ期、Ⅱ期,ANS⊥SN’、PNS⊥SN’等参数在治疗前后有显著性变化。4期治疗前后的参数变化绝对值的大小顺序依次为:QCVMⅠ期>QCVMⅡ期>QCVMⅢ期>QCVMⅣ期。结论 QCVM作为一种新的评估颅面部生长发育的量化标准,在预测上颌骨矫形治疗的最佳时机方面有较好的指导意义。

Objective To investigate the optimal treatment timing for maxillary skeletal retrusion according to quantitative cervical vertebral maturation（QCVM）. Methods One hundred and twenty patients（8. 5-15.6 years） who visited the Depart- ment of Orthodontics of Union Hospital（Wuhan,China） between December 2007 and October 2011 and presented with maxil- lary skeletal retrusion and Class lit malocclusion were enrolled and divided into four groups according to QCVM. With each group, the maxillary protraction was achieved by using the face mask for 6 months. Cephalometric variables after treatment were compared with those before treatment to evaluate the status of the maxillary bone. Results With patients at QCVM I , II and III stage, the sagittal parameters such as SNA,A-N perp, Co-A, ANB, convexity angle,Wits and ANS-PNSd_ SN＇ were signifi- cantly improved after treatment. Moreover,with patients at QCVM I and II stage, the vertical parameters such as ANS LSN＇ and PNSJ_SN were also improyed after treatment. The order of the parameter variation in different QCVM groups was QCVM I 〉QCVMII 〉QCVMIII 〉QCVMIV. Conclusion QCVM as a novel quantitative standard can characterize the development potential of the craniofacial bone and can be used to judge the optimal treatment timing for maxillary skeletal retrusion.