锥形束CT转化头颅侧位片定点精确性的研究

Objective In this study, we compared the precision of landmark identification using cephalograms from cone-beam computed tomographic (CBCT) volumes and conventional lateral cephalograms (Ceph). Methods Twenty pre-orthodontic patients were radiographed with conventional Ceph and CBCT techniques. CBCT data was uploaded into InvivoDental software 5.0 to generate cephalograms(CCB). Three observers plotted 23 landmarks using computer displays of CCB and Ceph views during separate sessions. Absolute differences between CCB and Ceph of all observers were measured. The absolute difference between each observer was also measured. ANOVA and paired t tests were used to analyze variability differences. Results The difference of landmark identification between CCB and Ceph were significant at P＜0.05 calculations. 8 landmarks variability was statistically greater than Ceph views. The variability of CCB for each observer was consistently greater than in Ceph. The overall correlation of CCB and Ceph measurements was excellent at 0.99.Conclusions The CCB displays of CBCT volume images provide generally more precise identification than Ceph. More precise location of basion, porion, orbitale, ANS, A point, Gonion and tooth apex overcomes the problem of superimposition of these bilateral landmarks seen in Ceph. Greater variability of certain landmarks is probably related to inadequate definition of the landmarks in the third dimension.

Precision of cephalometric landmark identification from cone-beam computed tomography