正畸疗效主、客观评价方法的有效性

Validation of subjective and objective evaluation methods for orthodontic treatment outcome

目的:探讨69位中国正畸专家对108例正畸完成病例疗效的主观判断结果与牙牙合模型及头颅侧位片客观测量结果的相关性,筛选重要的客观测量项目,并建立主、客观判断的回归模型。方法:从全国6所正畸院校2006年7月至2008年8月治疗完成的2 383个病例中,随机抽取108个病例作为样本。将样本的治疗后牙牙合模型和头颅侧位片作为主、客观评价材料,由69位中国正畸专家对样本的疗效水平进行主观评价,通过治疗标准指数(peer assessment rating,PAR)和美国正畸专家认证委员会-客观评分系统(American board of orthodontics-objective grading system,ABO-OGS)两种方法对样本的牙牙合模型进行客观测量,采用自主研发的二维头影测量软件对样本的头颅侧位片进行客观测量。以专家主观评价的均值作为因变量,客观测量结果作为自变量,通过Pearson相关分析和多元线性回归分析,建立回归模型。结果:与主观评价结果相关性最高的牙牙合模型资料客观测量项目为ABOOGS的牙合关系,相关系数为0.655(P<0.01),其次是PAR的覆盖,相关系数为0.525(P<0.01)。与主观评价结果相关性最高的头颅侧位片客观测量项目为下切牙的唇倾度,相关系数为0.446(P<0.01),其次是下唇的突度,相关系数为0.436(P<0.01)。多元线性回归分析结果中纳入回归方程的项目为ABO-OGS的排列、ABO-OGS的牙合关系、ABO-OGS的邻牙接触关系、L1/NB(°)、PAR的覆盖、SNB(°)、ABO-OGS的牙合接触、U1/SN2(°)和PAR的中线,回归方程的R2为0.72。结论:本回归模型能够有效地反映69位中国正畸专家对108例正畸患者疗效水平的主观评价金标准,从而客观地评判中国正畸治疗的疗效水平。

Objective： To assess the correlations between objective measurements of 108 finished orthodontic cases and subjective assessments made by 69 orthodontic specialists,to explore the statistically significant measuring categories of cast and cephalogram and to validate the regression model. Methods： A stratified random sample of 108 cases was drawn from the large sample of 2 383 patients who finished orthodontic treatment between July 2006 and August 2008 in six orthodontic treatment centers around China. For each patient,the post-treatment information sources evaluated in this study included standardized plaster study casts and a lateral cephalometric X-ray image. These information sources were evaluated both singly and in combination by a panel of 69 orthodontic specialists. The average subjective grading scores of 69 orthodontists were regarded as the gold standard. Six examiners used the peer assessment rating（ PAR） index and American board of orthodontics-objective grading system（ ABO-OGS） to measure all the study casts respectively and three other examiners measured all the lateral cephalometric X-ray images by using customized software. The objective measuring data were correlated with the gold standard. The correlations between the objective measurement and the subjective evaluation were assessed,the statistically significant measuring categories of cast and cephalogram were explored and the regression model was validated. Results： The ABO-OGS scores of ＂occlusal relationship＂correlated most strongly with the subjective scores of cast（ r = 0. 655,P 0. 01）,and the secondarily correlated category with those were the PAR scores of ＂overjet＂（ r = 0. 525,P 〈0. 01）. The proclination of the lower incisors correlated most strongly with the subjective scores of cephalogram（ r = 0. 446,P 0. 01）,and the secondarily correlated category with those was the protrusion of the lower lips（ r = 0. 436,P 0. 01）. Nine components were predictive for the post-treatment model and lateral cephalometric film（ Post-M ＋ C） outcome： alignment（ ABO-OGS）,occlusal relationship（ ABO-OGS）,interproximal contact（ ABO-OGS）,L1 /NB（ °）,overjet（ PAR）,SNB（ °）,occlusal contacts（ ABO-OGS）,U1 / SN2（ °） and centerline（ PAR）. These 9components accounted for 72% of the variability in the average subjective grading scores. Conclusion：The objective regression model could replace the averaged opinion of Chinese orthodontic experts effectively,making objective assessment of orthodontic treatment outcome for Chinese patients.