# Evaluation of Tooth Movement Accuracy with the F22 Aligner System: A Retrospective Study
## 3 Results  
Starting from a total of 254 cases affected by dental Class I malocclusion, after the use of inclusion and exclusion criteria, a final sample composed of 120 patients was investigated (Figure 1). The first phase of CAT with F22 aligners was accomplished with a mean number of aligners of 14.61 and 14.50, mean IPR values of 0.15 mm and 0.18 mm, and a mean number of grip points of 3.8 and 4 for maxillary and mandibular arch, respectively. Almost one posterior tooth (first or second molars) was not moved in the virtual set-up planning and thus it was used as tooth reference for the superimposition phase. In the descriptive analysis, means and SD were calculated for prescribed (1 T1 1), achieved (1 T2 1) and imprecision values (1 T2 - T1 1) of investigated movements (inclination, angle and rotation). In all cases, a reasonably appropriate observation number was obtained, with the exception of the tooth type molars (n = 19 and n = 21 for inclination, n = 2 and n = 3 for angulation and n = 27 and n = 18 for rotation, considering the maxillary and mandibular molars, respectively) (Table 1). Regarding the accuracy [(1 T2/T1 1) \(\times\) 100], a total mean value of approximately 86.76 \(\pm\) 0.44.89% (n = 975) was recorded for inclination. This was highest for the maxillary incisors, at 91.25 \(\pm\) 53.54% (n = 192), and lowest for the mandibular incisors, at 82.29 \(\pm\) 34.19% (n = 238). Mean angulation accuracy was 88.01 \(\pm\) 55.68% (n = 719), with a high of 98.29 \(\pm\) 73.42% (n = 42) at the maxillary premolars and a low of 72.73 \(\pm\) 41.45% (n = 97) at the maxillary amines. Rotation accuracy was on average 61.59 \(\pm\) 32.54% (n = 1224), and highest at the mandibular incisors, 72.64 \(\pm\) 32.06% (n = 307), and lowest at the maxillary amines, 49.59 \(\pm\) 29.43% (n = 128). Considering the average values of the two arches separately, there were no obvious differences in inclination or angulation accuracy, but there was a slight difference in rotation accuracy, which was 59.45 \(\pm\) 31.31% (n = 600) in the maxillary arch and 63.67 \(\pm\) 33.56% (n = 624) in the mandibular (Table 2). \begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c c c c c c c} \hline \hline  & & & \multicolumn{4}{c}{**Inclination**} & \multicolumn{4}{c}{**Anguidation**} & \multicolumn{4}{c}{**Rotation**} \\ \hline Arch & & & \multicolumn{4}{c}{**Techned**} & \multicolumn{4}{c}{**Achieved**} & \multicolumn{4}{c}{**Inprecision**} & \multicolumn{4}{c}{**Precolved**} & \multicolumn{4}{c}{**Achieved**} & \multicolumn{4}{c}{**Inprecision**} & \multicolumn{4}{c}{**Precolved**} & \multicolumn{4}{c}{**Outbiased**} & \multicolumn{4}{c}{**Inprecision**} \\  & & \multicolumn{4}{c}{**Moverments**} & \multicolumn{4}{c}{**Moverments**} & \multicolumn{4}{c}{**(1T \(\mathrm{T}\mathrm{T}\mathrm{T}\))**} & \multicolumn{4}{c}{**(1T \(\mathrm{T}\mathrm{T}\mathrm{T}\))**} & \multicolumn{4}{c}{**(1T \(\mathrm{T}\mathrm{T}\))**} & \multicolumn{4}{c}{**(1T \(\mathrm{T}\mathrm{T}\))**} & \multicolumn{4}{c}{**(1T \(\mathrm{T}\mathrm{T}\))**} & \multicolumn{4}{c}{**(1T \(\mathrm{T}\mathrm{T}\))**} & \multicolumn{4}{c}{**(1T \(\mathrm{T}\mathrm{T}\))**} \\ \hline \multirow{3}{*}{**Arch**} & **Tooth** & **N. Obser** & **Mean** & **SD** & **Mean** &  
Table 3 shows pairwise statistical comparisons of the accuracy at the various tooth types in the two arches. While no statistically significant differences were found in inclination, there were statistically significant differences in angulation accuracy in two pairwise comparisons, namely maxillary incisors (91.16 \(\pm\) 58.31%) and maxillary canines (72.3 \(\pm\) 41.45%), with \(p\) = 0.007, and maxillary incisors (91.16 \(\pm\) 58.31%) and mandibular premolars (79.51 \(\pm\) 69.65%), with \(p\) = 0.006. However, eight pairs displayed statistically significant differences in rotation accuracy.