## 3 Results  
Starting from a group of 78 patients, 50 patients (20 males and 30 females, mean age 19.32 \(\pm\) 8.96 years) were included in the study after the application of the inclusion and exclusion criteria. Of these, 25 patients were assigned to the 0.012 SS group and 25 to the 0.014 Ni-Ti group. The sample is described in Table 1. No patients withdrew from the study. The SSAS and STAI scores showed no statistically significant differences between the groups (Table 1). The results obtained from the STAI scale revealed that subjects of both groups reached scores higher than the cut-off point of 40, which indicated that all subjects enrolled in this study reported a high level of anxiety. No statistically significant differences between the groups were found concerning ALD (Table 1). These results confirmed the comparability between the groups in terms of ALD, sensory amplification and anxiety. There were statistically significant differences between the groups at T1, T3, T4, T5 and T6 (\(p\) < 0.05); the mean VAS values of the 0.012 SS group were significantly lower at each time point when compared with those of the 0.014 Ni-Ti group, especially during the most painful days (Figure 2 and Table 2). The linear regression analysis showed that neither the archive type nor the amount of crowding nor the SSAS score influenced the VAS values in the first 3 days of treatment (\(p\) > 0.05). \begin{table}
\begin{tabular}{c c c c c c} \hline \multirow{2}{*}{**Group**} & \multirow{2}{*}{**Gender**} & **Age** & **Arch Length Discrepancy** & **SSAS** & **TAI** \\  & & **(Mean \(\pm\) SD)** & **(mm, Median and** & **(Mean \(\pm\) SD)** & **(Mean \(\pm\) SD)** \\ \hline
0.012 SS (n = 25) & (9M; 16F) & 19.92 \(\pm\) 9.4 & \(-\)0.43 (\(-\)3.95\(-\)2.76) & 21.88 \(\pm\) 6.19 & 42.20 \(\pm\) 6.01 \\ \hline
0.014 Ni-Ti (n = 25) & (11M; 14F) & 18.32 \(\pm\) 8.31 & \(-\)1.7 (\(-\)3.70\(-\)4.40) & 24.36 \(\pm\) 5.41 & 43.36 \(\pm\) 3.92 \\ \hline \(p\)-Value & 0.564 & 0.528 & 0.764 & 0.138 & 0.423 \\ \hline \end{tabular}
\end{table} 
Table 1: Sample description. The \(p\)-value refers to the comparison between groups (t-test for independent samples or Mann–Whitney test). Figure 1: ALD evaluation with Delta-Dent software v1.0. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **0.012 SS** & **0.014 Ni-Ti** & \(p\)**-Value** \\ \hline T1 & 17.0 (4.0–26.0) & 34.0 (8.5–58.0) & 0.027 * \\ \hline T2 & 26.0 (11.5–47.0) & 41.0 (15.0–70.0) & 0.268 \\ \hline T3 & 21.0 (4.0–33.0) & 38.0 (20.0–65.5) & 0.017 * \\ \hline T4 & 13.0 (6.0–34.0) & 33.0 (16.5–66.5) & 0.046 * \\ \hline T5 & 8.0 (2.0–24.0) & 24.0 (11.0–57.5) & 0.018 * \\ \hline T6 & 9.0 (2.0–31.0) & 32.0 (10.5–51.5) & 0.039 * \\ \hline T7 & 10.0 (1.0–17.0) & 15.0 (2.0–46.5) & 0.147 \\ \hline T8 & 6.0 (1.5–18.0) & 15.0 (3.0–45.0) & 0.117 \\ \hline T9 & 4.0 (0.0–16.0) & 9.0 (1.5–37.0) & 0.199 \\ \hline T10 & 3.0 (0.0–16.0) & 6.0 (0.5–33.5) & 0.250 \\ \hline T11 & 1.0 (0.0–11.5) & 0.0 (0.0–35.5) & 0.686 \\ \hline T12 & 0.0 (0.0–12.5) & 0.0 (0.0–28.0) & 0.833 \\ \hline T13 & 0.0 (0.0–3.0) & 0.0 (0.0–30.5) & 0.456 \\ \hline T14 & 0.0 (0.0–2.0) & 0.0 (0.0–24.5) & 0.241 \\ \hline T15 & 0.0 (0.0–2.0) & 0.0 (0.0–15.0) & 0.170 \\ \hline T16 & 0.0 (0.0–0.0) & 0.0 (0.0–14.0) & 0.135 \\ \hline T17 & 0.0 (0.0–3.5) & 0.0 (0.0–12.5) & 0.206 \\ \hline T18 & 0.0 (0.0–3.5) & 0.0 (0.0–10.5) & 0.256 \\ \hline T19 & 0.0 (0.0–1.0) & 0.0 (0.0–6.5) & 0.462 \\ \hline T20 & 0.0 (0.0–0.5) & 0.0 (0.0–6.0) & 0.615 \\ \hline T21 & 0.0 (0.0–0.5) & 0.0 (0.0–5.5) & 0.697 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: VAS values in 0.012 SS and 0.014 Ni-Ti groups at each time point. Data are reported as mean and interquartile ranges. The \(p\)-value refers to the comparison between groups at each time point (Mann–Whitney test). * \(p\) < 0.05. Figure 2: Mean VAS values in 0.012 SS and 0.014 Ni-Ti groups during the first 15 days of treatment. * Statistically significant difference at each time point between groups (\(p\) < 0.05); M = morning; E = evening.