## 3 Results
### Comparing the Accuracy of iTero(r) Versus Trios(r)  
A _t_-test was performed to evaluate the accuracy of interdental space measurements observed in the four models, depending on the types of scanner used (iTero(r) or Trios(r)); the results are shown in Table 5 and Figure 9. Differences observed in all models with both iTero(r) and Trios(r) were statistically significant. However, deviations from Trios(r) were smaller than those from iTero(r) in all models. The significance of deviation in scanned images with the existing interdental spaces was less than that of the Ideal model; this observation was most prominent in the Severe model. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Models**} & \multicolumn{2}{c}{**Reference Scanner**} & \multicolumn{2}{c}{**Trios®**} \\ \cline{2-5}  & **Mean** & **Mean** & **Minimum Difference** & **Maximum Difference** \\ \hline Ideal & 46.0238 & 46.00 & 46.03 (0.00) & 45.75 (0.27) \\ Mild & 46.5214 & 46.53 & 46.51 (0.01) & 46.65 (0.13) \\ Moderate & 47.6796 & 47.46 & 47.60 (0.08) & 46.92 (0.76) \\ Severe & 48.45 & 48.41 & 48.41 (0.03) & 48.21 (0.24) \\ \hline \hline \end{tabular} Ideal: ideal dental arch; Mild: 1 mm spacing; Moderate: 3 mm spacing; and Severe: 5 mm spacing. Mean of reference scanner: average interpolar width was obtained by measuring the reference data three times; Mean of Trios®: average interpolar width of 10 scanned images was obtained by measuring the data three times using Trios®. Minimum difference. the minimum value of the difference between the mean of reference scanner and that of 10 scanned data from Trios®; Maximum difference: the maximum value of the difference between the mean of reference scanner and that of 10 scanned data from Trios®.  
\end{table} 
Table 4: Comparison of differences in interpolar widths between Trios® and the reference scanner (unit: mm). Figure 8: Representation of deviations when using Trios® Color map was set from 0 \(\upmu\)m to +200 \(\upmu\)m. Ideal: ideal dental arch; Mild: 1 mm spacing; Moderate: 3 mm spacing; and Severe: 5 mm spacing. Red represents areas of large deviations; Blue represents areas of small deviations. The deviation of Ideal is the smallest; that of Mild is larger than Ideal; that of Moderate is larger than Mild; and that of Severe is the largest, especially in the posterior area. A \(t\)-test was performed again to evaluate the accuracy of measurements observed in sectioned arches (LM, LP, Ant, RP, RM, Total) from iZero and Trios(r). The results are shown in Table 6 and Figure 10. Differences observed in each section of the arch were statistically significant, depending on the type of scanner (\(p<0.001\)). Deviations from Trios(r) in each section were smaller than those from iZero(r). Upon comparing deviations between the reference image and the scanned images, the differences were greater in LM and RM sections. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Section**} & \multicolumn{1}{c}{**iZero(r)**} & \multicolumn{1}{c}{**Trios(r)**} & \multirow{2}{*}{_p-Value_} \\ \cline{2-3} \cline{5-4}  & **Mean (SD)** & **Mean (SD)** & \\ \hline Ant & 53.70 (9.41) & 37.70 (7.23) & \textless{}0.001 \({}^{*}\) \\ LP & 71.36 (32.09) & 35.40 (11.58) & \textless{}0.001 \({}^{*}\) \\ RP & 70.00 (29.03) & 44.47 (16.07) & \textless{}0.001 \({}^{*}\) \\ LM & 139.24 (73.79) & 57.86 (33.69) & \textless{}0.001 \({}^{*}\) \\ RM & 136.57 (76.88) & 65.76 (41.99) & \textless{}0.001 \({}^{*}\) \\ Total & 90.72 (38.57) & 43.39 (13.17) & \textless{}0.001 \({}^{*}\) \\ \hline \hline \end{tabular} \({}^{*}\) Indicates that the values are statistically different between iZero and Trios® (\(p<0.05\)). Values obtained from every section (Ant, LP, RP, LM, RM, Total) using iZero® and Trios® are statistically different. \(p\)-values are \(\textless{}0.001\). SD: standard deviation. For the sectioned arch, Art is the anterior teeth, LP is the left premolars; RP is the right premolar; LM is the left molar; RM is the right molar; Total is the entire arch.  
\end{table}