# Accuracy of Different Head Movements of Intraoral Scanner in Full Arch of Both Maxilla and Mandible
## 3 Results  
Table 1 presents the mean absolute deviation of six head movements for trueness of the occlusal side. Both in the maxilla and mandible, the values demonstrated the significant difference among six head movements (_p_ < 0.05), where the 8-figure movement revealed the maximum deviation (0.132 \(\pm\) 0.099 mm) and the S-figure movement was the minimum value (0.080 \(\pm\) 0.065 mm). Detailed mutual comparisons are listed in Table 1. Deviations of the maxilla and mandible were statistically significant (_p_ < 0.05). Figure 4 clearly shows the occlusal deviation of different tooth positions among six head movements in the maxilla. The scan path was from the left second molar occlusal side, proceeding to the right second molar, then palatal side and buccal surface. Except for the 8-figure movement, the other head movements showed a similar trend, where deviations increased at the left central incisor, left first premolar, and left second molar. The statistical results showed a significant difference at the tooth positions 11, 12, and 16. Figure 5 reveals the occlusal deviations of different tooth positions among six head movements in the mandible. Except for the 8-figure and A-P movements, the others showed a similar trend: Deviation slightly increased at left, right second molar and right canine, and first premolar areas. Moreover, the tooth positions 45, 46, and 47 had significant difference; however, the deviation of tooth positions 42 and 43 slightly increased, although their statistical results were not different (_p_ = 0.082 and 0.0376, respectively). \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & \multicolumn{2}{c}{**Maxilla Value**} & \multicolumn{2}{c}{**Mandible Value**} \\ \hline  & **Mean \(\pm\) SD** & **95\% CI** & _p_**-Value** & **Mean \(\pm\) SD** & **95\% CI** & _p_**-Value** \\ \hline  & & \multicolumn{2}{c}{<0.001} & & \multicolumn{2}{c}{<0.001} & & \multicolumn{2}{c}{<0.001} \\ Linear & 0.095 \(\pm\) 0.08 \({}^{\mathrm{a.c}}\) & (0.082, 0.109) & & 0.079 \(\pm\) 0.039 \({}^{\mathrm{a.g}}\) & (0.073, 0.086) \\ Circle & 0.095 \(\pm\) 0.07 \({}^{\mathrm{a.c}}\) & (0.083, 0.107) & & 0.076 \(\pm\) 0.038 \({}^{\mathrm{d}}\) & (0.070, 0.082) \\ Wave & 0.093 \(\pm\) 0.07 \({}^{\mathrm{a.c}}\) & (0.081, 0.107) & & 0.078 \(\pm\) 0.044 \({}^{\mathrm{a.g}}\) & (0.071, 0.086) \\
8 & 0.132 \(\pm\) 0.099 \({}^{\mathrm{b}}\) & (0.116, 0.149) & & 0.114 \(\pm\) 0.079 \({}^{\mathrm{a.g}}\) & (0.101, 0.127) \\ S & 0.080 \(\pm\) 0.065 \({}^{\mathrm{a}}\) & (0.069, 0.091) & & 0.074 \(\pm\) 0.038 \({}^{\mathrm{d}}\) & (0.068, 0.081) \\ A-P & 0.112 \(\pm\) 0.078 \({}^{\mathrm{b.c}}\) & (0.099, 0.125) & & 0.098 \(\pm\) 0.096 \({}^{\mathrm{a.g}}\) & (0.082, 0.114) \\ \hline \hline \end{tabular} Different superscript letters in a column indicate statistical significance among groups (_p_ < 0.05; post hoc Tukey test); one-way ANOVA (K independent groups).  
\end{table} 
Table 1: Mean absolute deviations of maxilla and mandible occlusal side (mm). Figure 3: The measuring point of occlusal surface (**A**) and B-L surface (**B**). The mean absolute deviations of buccal-lingual side in the maxilla and mandible are presented in Table 2. The six head movements showed a significant difference (\(p<0.05\)). In the maxilla, the deviation value of the S-figure movement (0.166 \(\pm\) 0.221 mm) was the maximum among the six, and the linear movement showed the minimum values (0.098 \(\pm\) 0.073 mm). In the mandible, the 8-figure movement revealed the maximum deviation (0.095 \(\pm\) 0.057 mm), and circle head movement showed the minimum values (0.070 \(\pm\) 0.044 mm). Figure 6 clearly shows the B-L deviation of different tooth positions among six head movements in the maxilla. Head movements Linear, Circle, and A-P showed similar trends with lower ups and downs, while the 8-, S-figure, and Wave movements undulated obviously at the upper left canine area. The statistical result showed only that tooth position 23 showed a significant difference.