6种软组织分析法在骨性Ⅲ类错[牙合]侧貌评价中的比较研究

Comparative study of six different soft tissue analyses in evaluation of soft tissue profile in skeletal Class Ⅲ malocclusion

目的探寻骨性Ⅲ类错[牙合]软组织特征的头影测量敏感指标。方法选择65例正常[牙合]、40例骨性Ⅲ类错[牙合]治疗前后X线头颅侧位片，选择6种唇部软组织侧貌分析法的14个头影测量项目对145个样本进行测量，各测量指标进行多因素逐步判别分析，并对判别结果进行ROC曲线（receiver operating characteristic curve，受试者工作特征曲线）评价，获得判断骨性Ⅲ类错[牙合]软组织侧貌特征的敏感指标。结果多因素逐步判别结果显示，14个测量项目中LLSn FH、UL-B线、Lip-Diff及H角对Ⅲ类错[牙合]侧貌的判断更有意义。进一步研究中，ROC曲线结果显示，在这四个有较好诊断意义的测量项目里，LL-Sn FH更适合诊断凹面型，其AUC值（area under the curve，曲线下面积）为0．970，Lip-Diff及H角更适合评价Ⅲ类错[牙合]侧貌的治疗效果，其AUC值分别为1．000和0．919。此时三者的灵敏度和特异度都较高。结论Lip-Diff是骨性Ⅲ类错[牙合]侧貌评价的一个较理想的指标，相对于其他传统侧貌测量参考线，能兼顾到较好的诊断能力和评价治疗效果的能力，使用上更加方便直接。

Objective To find out the most sensitive cephalometric variable in the evaluation of the soft tissue profile in skeletal Class Ⅲ patients. Methods Cephalographs were taken in one hundred and forty-five individuals （including 65 subjects with normal occlusion, 40 patients with skeletal Class Ⅲ malocclusion before treatment and 40 patients with skeletal Class Ⅲ malocclusion after treatment）. Six different soft tissue analyses were employed and 14 variables were measured. Multiple factorial discriminate analysis and ROC （receiver operating characteristic curve） were used to find out the valuable diagnostic variables to evaluate the soft tissue profile. Results Multiple factorial discriminate analysis indicated that LI.-Sn FH, UL-B, Lip-Diff and H angle were valuable in diagnosing skeletal Class Ⅲ profile. The further study of ROC indicated that LL-SnJ FH was more powerful in diagnosing and the AUC （area under the curve） was 0. 920, while Lip Diff and H angle were better at evaluating the treatment effect of skeletal Class Ⅲ profile and the AUCs were 1. 000 and 0. 919, respectively, These three variables had high sensitivity and specificity. Conclusion Lip-Diff was the most efficient and convenient variable in the evaluation of Class Ⅲ profile.