应用Coben分析法评价前方牵引治疗上颌发育不足的临床疗效

目的 应用Coben分析法评价前方牵引治疗上颌发育不足的临床疗效，阐明Coben分析法在骨性安氏Ⅲ类错牙合畸形致病机制的诊断及矫治计划制定中的优势。方法 对120例处在生长发育期的由上颌发育不足所致的骨性安氏Ⅲ类错患者行上颌前方牵引治疗，分别对上颌前方牵引矫治前、后的头颅定位侧位片采用Coben分析法和北医大分析法进行头影测量分析。结果 上颌前方牵引后，Coben分析法测量结果中，面中1/3深度增加且Ptm-A段的变化有统计学差异，面下1/3深度减小，颜面高度增加（P<0.001）；北医大分析法测量结果中，SNA、ANB、U1/NA、U1/SN、MP/SN、Y轴角显著增加（P<0.001），SNB、U1/L1显著减小（P<0.001），L1/MP减小（P<0.05）。结论 上颌前方牵引疗法对以Coben分析法中Ptm-A段过小为主要机制的生长发育期骨性安氏Ⅲ类错畸形有显著疗效；Coben分析法是一种比较直观、容易理解的头影测量分析方法，在错畸形尤其是骨性安氏Ⅲ类错的诊断中具有临床意义。

Using Coben analysis to evaluate the therapeutic effect of maxillary protraction on maxillary maldevelopment

Objective  We aims to evaluate the therapeutic effect of maxillary protraction on maxillary maldevelopment using Coben analysis to illustrate the advantages of Coben analysis in identifying pathogenic mechanisms and in designing treatment plans for Class Ⅲ malocclusions. Methods  A total of 120 patients were diagnosed to have skeletal Class Ⅲ malocclusions with maxillary maldevelopment. These patients were selected as the subjects of the present research. Maxillary protraction was exerted to promote maxilla growth. Cephalometric analysis was conducted by using Coben analysis and angle analyses of Beijing Medical University to collect data before and after maxillary protraction. Results  According to Coben analysis measurements, the height of facies cranii increased after maxillary protraction. The depth of lower face decreased, whereas that of mid-face increased and the Ptm-A value increased significantly in the mid-face (P<0.001). In the angle analysis of Beijing Medical University, SNA, ANB, U1/NA, U1/SN, MP/SN, and Y-axis angles increased significantly (P<0.001), whereas SNB, U1/L1 (P<0.001), and L1/MP (P<0.05) decreased. Conclusion  Maxillary protraction has a significant effect on growing skeletal Class Ⅲ malocclusions with the chief mechanism of Ptm-A value just diagnosed as minor by Coben analysis. Coben analysis is visual and clear in identifying pathogenic mechanisms of Class Ⅲ malocclusions.