三维转化头影测量法评估咬合垂直距离的研究

Cone-beam computed tomography-synthesized cephalograms for evaluating the vertical dimension of occlusions

目的对三维转化头影测量法、发音法及息止间隙法确定的云南省汉族无牙颌患者咬合垂直距离的准确性进行比较和分析。方法首先建立云南省汉族正常者锥形束CT(CBCT)头颅侧位影像各标志点间相关性数据库,随后选取5名63～78岁云南省汉族无牙颌患者,使用NNT.View软件对由CBCT转化的头颅侧位片的各硬组织标志点进行测量分析,结合正常人群数据库,评估出咬合垂直距离,并对CBCT转化头影测量法、发音法及息止间隙法确定的咬合垂直距离进行分析。结果本研究以发音法为标准参照组,分析了息止间隙法和6种CBCT转化头影测量法(包括N-ANS/ANS-Me、S-Go/N-Me、ANS-Gn/N-ANS、ANS-FH/Me-FH、ANS-Xi-Pm、CA/LA)与发音法的差值,结果发现:7种测量方法与发音法均有很高的一致性(组内相关系数>0.986);其中息止间隙法、N-ANS/ANS-Me、S-Go/N-Me法差值的绝对值较其他4组更小,而ANS-FH/Me-FH差值的绝对值最大,差异均有统计学意义(P<0.05)。结论三维转化头影测量法除ANS-FH/Me-FH外,其余5种方法均可为临床评估无牙颌患者咬合垂直距离提供参考。

Objective The accuracy of the occlusion vertical dimensions of edentulous Han patients from Yunnan province was compared and analyzed on the basis of cone-beam computed tomography(CBCT)-synthesized cephalograms,closest speaking space method,and interocclusal distance.Methods A database correlating the CBCT head lateral images of Han patients from Yunnan province with normal occlusal conditions was first constructed.Then,five edentulous Han patients aged 63–78 years old from Yunnan Province were selected.NNT.View software was used to measure and analyze hard tissue cephalometric radiographs that had been transformed by the CBCT marker.The radiographs were then combined with the normal population database for the assessment of occlusion vertical dimensions.The occlusion vertical dimensions determined on the basis of CBCT-synthesized cephalograms,the closest speaking space method,and the free-way space were analyzed.Results The closest speaking space method was used as the standard control group,the differences between seven methods and the closest speaking space method were analyzed.The seven methods include free-way space method and six CBCTsynthesized cephalograms methods(N-ANS/ANS-Me,S-Go/N-Me,ANS-Gn/N-ANS,ANS-FH/Me-FH,ANS-Xi-Pm,and CA/LA).The seven methods were highly consistent with the closest speaking space method(intraclass correlation coefficient >0.986).The absolute values of the differences between the methods of free-way space,N-ANS/ANS-Me,S-Go/N-Me and the closest speaking space method were lower than those of the other four groups(P<0.05),while the differences between ANS-FH/Me-FH and the closest speaking space method was higher than those other groups(P<0.05).Conclusion CBCT-synthesized cephalograms,with the exception of ANS-FH/Me-FH,can provide references for the clinical evaluation of the occlusion vertical dimensions of patients with edentulous jaws.