Accuracy of integration of dental cast and cephalograms compared with cone-beam computed tomography: a comparative study

This study proposes a method that integrates maxillary dental cast and cephalograms and evaluates its accuracy compared with cone-beam computed tomography (CBCT) scans. The study sample comprised 20 adult patients with records of dental casts, cephalograms, and craniofacial CBCT scans. The maxillary dental cast was integrated with lateral and frontal cephalograms based on best-fit registration of palatal and dental outline curves from dental cast with cephalogram tracings. Linear measurement was conducted to assess the intra- and inter-examiner reproducibility of the proposed integration method using intraclass correlation coefficients; linear and angular measurements were conducted to assess its accuracy with CBCT scans as a standard reference. Paired t test, one sample t test, and mean +/- standard deviation of the absolute value of difference were used to compare the integrated images and CBCT. The integration method showed good intra- and inter-examiner reproducibility (intraclass correlation coefficients > 0.98). The differences in linear and angular measurements between the integrated images and CBCT were not statistically significant but with a large deviation. When absolute value of difference was computed, the linear distance error was 0.51 +/- 0.34 mm, the tooth point coordinate errors in X, Y and Z axes were 0.22 +/- 0.22, 0.38 +/- 0.32 and 0.21 +/- 0.21 mm, respectively; the angular error in pitch, roll and yaw of the dental cast was 0.82 +/- 0.51, 0.92 +/- 0.59 and 0.80 +/- 0.41 degree, respectively. The proposed method for integration of dental cast and cephalograms showed good reproducibility and acceptable accuracy compared with CBCT. It could be helpful for researchers to study three-dimensional tooth growth changes using the existing craniofacial growth data especially cephalograms.