## 4 Discussion  
We compared various dental measurements by using plaster and digital models scanned by the Primescan system. Measurements on both the upper and lower jaws were taken by three blind examiners. Statistically significant differences were observed in measurements in tooth 15 (widths) and tooth 34 (heights), with tiny discrepancies of 0.03 and 0.01 mm. The Bland-Altman plots of almost all of measurements of tooth heights and widths showed that differences between the two models were within the limits of agreement. Measurements of overjet, overbite, arch width, and depth between both models showed no significant difference. The inter-examiner and intra-examiner errors were statistically insignificant, showing excellent reliability. In the research, the age ranges were 19-30 years old, in which the permanent teeth from the first molars on both the right and left sides are fully erupted. Adolescent age groups are likely chosen because teeth at this age are less likely to be damaged and worn, allowing for more accurate tooth size measurements. Factors affecting the accuracy of intraoral scanners can include the length of the missing teeth, the digital procedure, and the characteristics of the scanned surface [11]. Intraoral scanner systems operate by projecting light onto the scanned surface and capturing the reflected images. Therefore, excessive light reflection, such as from metallic restoration surfaces, excessive saliva, or hard-to-reach areas, can affect the quality and clarity of the captured images. Intraoral scanners cannot capture the entire image of the area to be scanned in a single pass; instead, they perform multiple overlapping image captures and stitch the images together using algorithms. Each time the images are stitched together, there is a risk of creating certain deviations. Hence, when the digital area is large, especially in the case of long lengths of missing teeth, the resulting deviations will be greater. Surfaces with many anatomical structures provide numerous reliable reference points for overlapping scanned images, increasing accuracy. When performing a digital scan of the entire dental arch, starting the scan at the palate, where there are more anatomical structures, results in higher accuracy [12]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Tooth** & \begin{tabular}{c} **Measureer** \\ **One** \\ \end{tabular}  & \begin{tabular}{c} **Measureer** \\ **Two** \\ \end{tabular}  & \begin{tabular}{c} **Measureer** \\ **Three** \\ \end{tabular}  & \begin{tabular}{c} **Tooth** \\ **One** \\ \end{tabular}  & \ \begin{tabular}{c} **Measureer** \\ **Two** \\ \end{tabular}  & \begin{tabular}{c} **Measureer** \\ **Three** \\ \end{tabular}  \\ \hline W26 & 0.720 & 0.993 & 0.965 & H26 & 0.924 & 0.964 & 0.957 \\ \hline W31 & 0.824 & 0.881 & 0.985 & H31 & 0.964 & 0.977 & 0.975 \\ \hline W32 & 0.668 & 0.848 & 0.834 & H32 & 0.982 & 0.909 & 0.986 \\ \hline W33 & 0.903 & 0.860 & 0.978 & H33 & 0.999 & 0.978 & 0.996 \\ \hline W34 & 0.954 & 0.908 & 0.984 & H34 & 0.998 & 0.981 & 0.987 \\ \hline W35 & 0.648 & 0.835 & 0.941 & H35 & 0.942 & 0.891 & 0.980 \\ \hline W36 & 0.755 & 0.851 & 0.983 & H36 & 0.966 & 0.881 & 0.958 \\ \hline W41 & 0.867 & 0.934 & 0.973 & H41 & 0.977 & 0.952 & 0.989 \\ \hline W42 & 0.716 & 0.939 & 0.912 & H42 & 0.954 & 0.980 & 0.984 \\ \hline W43 & 0.804 & 0.965 & 0.997 & H43 & 0.996 & 0.970 & 0.986 \\ \hline W44 & 0.809 & 0.981 & 0.976 & H44 & 0.994 & 0.930 & 0.992 \\ \hline W45 & 0.988 & 0.874 & 0.939 & H45 & 0.949 & 0.936 & 0.975 \\ \hline W46 & 0.967 & 0.655 & 0.661 & H46 & 0.844 & 0. The only discrepancies in measurements of tooth 15 (widths) and tooth 34 (heights) between plaster and digital models were observed potentially due to the teeth location. The difficulty in accessing the posterior areas of the dental arch when maneuvering the scanner head due to tongue movement and limited mouth opening can cause distortion during digital modeling [13]. The results showed no difference in the measurements of overjet and overbite. Similarly, [PERSON] et al.