牵引成骨术联合正畸矫治骨性上颌后缩的硬组织变化

The Changes of Hard Tissue after Maxillary Advancement by Distraction Osteogenesis and Orthodontics

目的 应用Pancherz头影测量分析法观测牵引成骨技术联合正畸矫治前后颌面部硬组织,特别是上颌骨的位置变化。方法 对6例采用正畸联合牵引成骨术前牵引矫治严重上颌后缩的患者,采用Pancherz头影测量分析法进行研究。以S点为基准,重叠头影侧位定位片上的SN连线,并将治疗前的OLp线转移到治疗后的定位片上,测量8项指标。结果 覆盖平均由- 6 .37mm变为1.9mm ,平均增大8.2 7mm ,统计学分析差别有显著性(P <0 .0 1) ;上颌骨平均前移2 .2 7mm ,治疗前后统计分析差异有显著性(P <0 .0 5 ) ;上切牙切缘平均前移4 .97mm ,差异有显著性(P <0 .0 5 )。下切牙舌倾,下颌骨有一定程度的向下向后旋转。结论 Pancherz头影测量分析法,可以很明确的反映上颌后缩以联合法矫治前后颌面部硬组织在矢状方向上的位置变化。本研究中,上颌后缩患者反牙合的矫治主要因上颌骨、上切牙的前移而解除,但下颌骨和下切牙位置的变化,提示选择适应证时应避免上颌后缩同时伴有高角和(或)下颌后缩的患者。

Objective To evaluate the changes of hard tissues before and after treatment with distraction osteogenesis and orthodontics. Methods 6 cases with severe maxillary hypoplasia were treated by DO after Le Fort Ⅰ osteotomy and analysed by Pancherz analysis. Superimposing the pre-treatment tracing (T1) and post-treatment tracing (T2) on the SN line with S point as the registration point was used. The OLp line was transferred from T1 to T2 so that the tracings could be analysed in the same grid and then the items were measured. Results The overjet changed from -6.37 mm to 1.9 mm (P< 0.01) . The advancement of maxilla was 2.27 mm (P<0.05) and labial movement of upper incisor edge was 4.97 (P< 0.05) . The mandible and lower incisor edges had a small degree of backward and downward rotation and lingual inclination respectively. Conclusion Pancherz analysis is a very good method to reflect the changes of hard tissue before and after maxillary advancement by DO. The correction of negative overjet in the study is mainly due to the advancement of maxilla and upper incisors, but the position changes of mandible and lower incisors implies that severe maxillary hypoplasia with high angle and/or mandibular retrusion is contraindicated by this method.