## 3 Results
### Comparison of Accuracy with the Increase in Anterior Interdental Space
The highest deviation occurred in the right molar region upon scanning the full arch from the left side; greater deviation was observed in the most distal region of the scanned area opposite to the starting point of the scanner. The superimposed models from Trios(r) are portrayed in color, as shown in Figure 8. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Models**} & **Reference Scanner** & \multicolumn{2}{c}{**iTero®**} \\ \cline{2-5}  & **Mean** & **Mean** & **Minimum Difference** & **Maximum Difference** \\ \hline Ideal & 46.02 & 46.23 & 46.02 (0.00) & 46.56 (0.54) \\ Mild & 46.52 & 46.69 & 46.48 (0.04) & 46.89 (0.37) \\ Moderate & 47.68 & 47.79 & 47.65 (0.03) & 48.34 (0.66) \\ Severe & 48.45 & 48.82 & 48.54 (0.09) & 49.08 (0.64) \\ \hline Ideal: ideal dental arch; Mild: 1 mm spacing; Moderate: 3 mm spacing; and Severe: 5 mm spacing. Mean of reference scanner: average intermolar width when the data was collected three times using reference scanner; Mean of of iTero®: average intermolar width of 10 scanned images by measuring the data 3 times using iTero®. Minimum difference: the minimum value of the difference between the mean of reference scanner and 10 scanned data from iTero®; Maximum difference: the maximum value of the difference between the mean of reference scanner and 10 scanned data from iTero®. & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of differences in intermolar widths between iTero® and the reference scanner (unit: mm). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**SectionsModels**} & **Ideal** & **Mild** & **Moderate** & **Severe** & \multirow{2}{*}{_p-Value f_} \\ \cline{2-5}  & **Mean (SD)** & **Mean (SD)** & **Mean (SD)** & **Mean (SD)** & \\ \hline Ant & 26.78 (2.72) \({}^{\text{a,A}}\) & 40.16 (2.53) \({}^{\text{b}}\) & 41.34 (5.21) \({}^{\text{b,A}}\) & 42.51 (2.45) \({}^{\text{b,A}}\) & \textless{0.001 *} \\ LP & 29.27 (4.13) \({}^{\text{A}}\) & 34.22 (7.85) & 37.34 (9.76) \({}^{\text{A}}\) & 40.78 (18.09) \({}^{\text{A}}\) & 0.146 \\ RP & 35.39 (7.03) \({}^{\text{a,A}}\) & 38.62 (10.12) \({}^{\text{ab}}\) & 49.65 (15.11) \({}^{\text{bc,AB}}\) & 54.20 (21.78) \({}^{\text{c,A}}\) & 0.020 * \\ LM & 47.63 (15.85) \({}^{\text{B}}\) & 48.29 (24.16) & 61.14 (24.08) \({}^{\text{BC}}\) & 74.38 (54.49) \({}^{\text{AB}}\) & 0.242 \\ RM & 49.53 (17.10) \({}^{\text{B}}\) & 51.83 (29.69) & 69.97 (37.69) \({}^{\text{C}}\) & 91.69 (61.40) \({}^{\text{B}}\) & 0.083 \\ Total & 32.21 (4.97) \({}^{\text{a,A}}\) & 41.38 (7.95) \({}^{\text{ab}}\) & 47.48 (11.24) \({}^{\text{b,AB}}\) & 52.47 (16.83) \({}^{\text{c,A}}\) & 0.002 * \\ \(p\)-value \(ff\) & \textless{0.001 **} & 0.209 & 0.006 ** & 0.018 ** & - \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Comparison of deviations in the scanned images of the four models from Trios® (unit: \(\upmu\)m). For the comparison of interpolar widths, three measurements of interpolar width were taken from the reference image and the scanned images; then, the average interpolar widths were calculated. The minimum and the maximum differences between the mean of the reference scanner and that of Trios(r) were calculated (Table 4). The highest deviation in the interpolar width from Trios(r) was 0.76 mm. A _t_-test was performed on the first and second sets of measurements to validate the precision of interpolar width measurements. The differences in the interpolar widths were statistically insignificant, with a _p_-value of 0.95.