## 3 Results
### Evaluation of DSR View
#### 3.2.2 Objective Verification of the Accuracy of DSR View  
To verify the accuracy of DSR View, we compared the interdental distance of the actual dental education models (SHOFU INC., Japan) [27] and the distance of the 3D-CG naked-eye stereoscopic display of the DICOM data obtained by CT imaging from the actual models. In this evaluation, we used five different actual models for dental education. We captured CT (CANON MEDICAL SYSTEMS, Aquilion Lightning, Othawara, Japan) images of five different models and acquired DICOM data. DSR View displayed the DICOM data of each model three-dimensionally to the naked eye. The measurer was able to see the model in a truly three-dimensional manner and accurately measure any interdental distances using a caliper. We manually measured the horizontal interdental distance and the depth interdental distance for each model with a high-precision digital display caliper ([PERSON], Digital Ruler No.19975, Sanjyo, Japan) capable of measuring in 0.01 mm increments for the substantive model. The same digital caliper was used by the measurer to manually measure the same part of the model displayed by DSR View. For each model, we measured two positions in the horizontal direction and two locations in the depth direction, for a total of four positions. Position a in the horizontal direction is the smallest interdental distance; Position b is the largest interdental distance. Position a in the depth direction is the maximum interdental distance; Position b is the length of the first premolar in the depth direction. The measurement results are shown in Tables 3 and 4, where the difference was less than 0.01 mm. Figures 14 and 15 show examples of measurements in the horizontal direction, whereas Figures 16 and 17 show examples of measurements in the depth direction. Table 3 shows the measurement results in the horizontal direction, and Table 4 shows the measurement results in the depth direction. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**Amount of Information Displayed by SRD**} \\ \cline{3-6}  & & **Extremely** & **Moderately** & **Neither** & **Moderately** & **\(p\)******* \\ \cline{3-6}  & Extremely well & \(15\) & \(2\) & \(0\) & \(0\) \\ \cline{3-6}  & & 88.2\% & \(11.8\%\) & \(0.0\%\) & \(0.0\%\) \\ \cline{3-6} Comprehension of anatomy using SRD & Very well & \(28\) & \(30\) & \(1\) & \(2\) \\ \cline{3-6}  & & 45.9\% & \(49.2\%\) & \(1.6\%\) & \(3.3\%\) \\ \cline{3-6}  & Moderately well & \(5\) & \(6\) & \(2\) & \(1\) \\ \cline{3-6}  & & 35.7\% & \(42.9\%\) & \(14.3\%\) & \(7.1\%\) \\ \hline \hline \end{tabular} \({}^{*}\) [PERSON]’s exact test.  
\end{table} 
Table 2: Correlation between the comprehension of anatomy and the amount of information displayed by the SRD. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Model No.** & **Position** & **Actual Model** & **DSR View** & **Difference** \\ \hline \multirow{3}{*}{1} & a & 13.02 & 13.02 & 0.00 \\ \cline{2-5}  & b & 7.25 & 7.25 & 0.00 \\ \hline \multirow{3}{*}{2} & a & 10.33 & 10.33 & 0.00 \\ \cline{2-5}  & b & 7.21 & 7.21 & 0.00 \\ \hline \multirow{3}{*}{3} & a & 18.01 & 18.01 & 0.00 \\ \cline{2-5}  & b & 7.83 & 7.83 & 0.00 \\ \hline \multirow{3}{*}{4} & a & 43.56 & 43.56 & 0.00 \\ \cline{2-5}  & b & 7.24 & 7.24 & 0.00 \\ \hline \multirow{3}{*}{5} & a & 17.70 & 17.70 & 0.00 \\ \cline{2-5}  & b & 7.37 & 7.37 & 0.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Measurement results in the depth direction. Figure 14: Measurement in the horizontal direction.