全景及根尖片对正畸相关牙根吸收诊断准确性的研究

目的以CBCT对样本牙根吸收的诊断结果为金标准,检验全景片（OPG）及根尖片对正畸相关牙根吸收（RRAOF）定性及分级半定量诊断结果的准确性。方法纳入完成固定正畸治疗的32例患者的121颗上前牙,正畸治疗前后均拍摄OPG、上前牙根尖片、上前牙CBCT。由3名放射专科医生按照Levander and Malmgren分度法对纳入样本的3种图像的牙根吸收程度分别进行评估,并以CBCT的诊断结果为金标准,检验OPG及根尖片对相同样本牙根吸收定性及分级半定量诊断结果的准确性。结果OPG、根尖片对相同样本RRAOF的定性及分级半定量诊断结果,与CBCT相比较均存在统计学差异（P<0.05）。根尖片和OPG对RRAOF定性诊断的敏感性分别为71.6%和78.4%,特异性分别为25.5%和51.1%,准确度分别为53.7%和67.8%。结论根尖片与OPG对正畸相关牙根吸收的诊断准确性较差。

Diagnostic accuracy of orthopantomogram and periapical film in evaluating root resorption associated with orthodontic force

Objective To test the diagnostic accuracy of qualitative and semi-quantitative evaluations on root re-sorption associated with orthodontic force(RRAOF) using orthopantomogram(OPG) and periapical film,through comparing with assessments with cone beam computed tomography(CBCT),which is considered as the gold standard.Methods Before and after treatment,OPG,periapical film,CBCT images of 121 upper anterior teeth in 32 orthodontic patients were obtained.Blind evaluation of RRAOF was performed according to Levander and Malmgren’s method by three trained radiographers through examining three kinds of images of these teeth.The diagnostic accuracy of qualitative and semi-quantitative evaluations on RRAOF using OPG and periapical films were test through comparing with assess-ments with CBCT,which was considered as the gold standard.Results To the same sample,the RRAOF qualitative and semi-quantitative diagnostic classification results of OPG and periapical films compared with CBCT were significant differences(P<0.05).The sensitivity of periapical films and OPG was 71.6% and 78.4%.The specificity of periapical films and OPG was 25.5% and 51.1%.The accuracy of periapical films and OPG was 53.7% and 67.8%,respectively.Conclusion Periapical films and OPG for evaluating RRAOF have a poor diagnostic accuracy.