## 3 Results  
The results of the measurements are summarized in Table 1.  
For what concerns the amines, a 4.7 \(\pm\) 2.3 mm dental expansion was observed in the IF cases against the 5.6 \(\pm\) 1.9 mm of the LE cases. On the gingival level, the canine's expansion was 2.5 \(\pm\) 1.6 mm for the IF cases and 3.6 \(\pm\) 1.7 mm for the LE cases. \begin{table}
\begin{tabular}{c c c c c c c} \hline  & \multicolumn{2}{c}{**First (n = 30)**} & \multicolumn{2}{c}{**Leaf (n = 38)**} & \multicolumn{2}{c}{**Net**} & \multicolumn{2}{c}{**Test T**} \\ \cline{2-7}  & **Mean** & **sd** & **Mean** & **sd** & **Difference** & **First vs. Leaf** \\ \hline
16-26 (CMP) & 40.0 & 2.9 & 38.1 & 2.5 & \(-\)1.9 & 0.01 * & T0 vs. T0 \\ \hline
36-46 (FC) & 42.3 & 2.7 & 42.0 & 2.2 & \(-\)0.3 & 0.68 & T0 vs. T0 \\ \hline
53-63 T0 & 31.3 & 2.9 & 29.8 & 2.1 & \(-\)15.0 & 0.03 * & T0 vs. T0 \\ \hline
53-63 T1 & 36.2 & 1.7 & 35.4 & 1.7 & \(-\)0.8 & & \\ \hline
53-63 T1-T0 & 4.7 & 2.3 & 5.6 & 1.9 & 0.9 & 0.12 & T0 vs. T1 \\ \hline
16-26 T0 & 44.8 & 2.9 & 42.9 & 2.4 & \(-\)1.9 & 0.01 * & T0 vs. T0 \\ \hline
16-26 T1 & 48.1 & 3.0 & 47.3 & 2.9 & \(-\)0.8 & & \\ \hline
16-26 T1-T0 & 3.2 & 1.2 & 4.4 & 1.4 & 1.2 & \(<\)0.01 * & T0 vs. T1 \\ \hline
54-64 T0 & 33.8 & 2.5 & 32.4 & 2.6 & \(-\)1.4 & 0.04 * & T0 vs. T0 \\ \hline
54-64 T1 & 38.7 & 1.8 & 37.9 & 2.1 & \(-\)0.8 & & \\ \hline
54-64 T1-T0 & 4.8 & 1.7 & 5.5 & 1.8 & 0.7 & 0.14 & T0 vs. T1 \\ \hline
55-65 T0 & 39.2 & 2.7 & 37.7 & 1.9 & \(-\)1.5 & 0.02 * & T0 vs. T0 \\ \hline
55-65 T1 & 43.6 & 2.4 & 42.9 & 2.2 & \(-\)0.7 & & \\ \hline
55-65 T1-T0 & 4.5 & 1.6 & 5.2 & 1.5 & 0.7 & 0.11 & T0 vs. T1 \\ \hline Arch Perimeter T0 & 74.7 & 5.3 & 72.1 & 4.1 & \(-\)2.6 & 0.05 * & T0 vs. T0 \\ \hline Arch Perimeter T1 & 77.1 & 3.4 & 76.3 & 4.7 & \(-\)0.8 & & \\ \hline Arch Perimeter T1-T0 & 2.3 & 3.0 & 4.2 & 2.9 & 1.9 & 0.02 * & T0 vs. T1 \\ \hline
53-63G T0 & 24.1 & 2.4 & 22.9 & 1.8 & \(-\)1.2 & 0.04 * & T0 vs. T0 \\ \hline
53-63G T1 & 26.7 & 1.7 & 26.5 & 2.4 & \(-\)0.2 & & \\ \hline
53-63G T1-T0 & 2.5 & 1.6 & 3.6 & 1.7 & 1.1 & 0.01 * & T0 vs. T1 \\ \hline
54-64G T0 & 26.1 & 2.5 & 24.9 & 2.1 & \(-\)1.22 & 0.06 * & T0 vs. T0 \\ \hline
54-64G T1 & 28.9 & 2.1 & 29.0 & 1.9 & 0.1 & & \\ \hline
54-64G T1-T0 & 2.8 & 2.0 & 4.1 & 1.5 & 1.3 & 0.01 * & T0 vs. T1 \\ \hline
55-65G T0 & 30.7 & 2.6 & 28.3 & 2.4 & \(-\)2.4 & \(<\)0.01 * & T0 vs. T0 \\ \hline
55-65G T1 & 33.1 & 2.3 & 32.8 & 2.2 & \(-\)0.3 & & \\ \hline
55-65G T1-T0 & 2.4 & 1.8 & 4.5 & 1.6 & 2.1 & \(<\)0.01 * & T0 vs. T1 \\ \hline
16-26G T0 & 34.3 & 3.0 & 32.2 & 2.7 & \(-\)2.1 & 0.01 * & T0 vs. T0 \\ \hline
16-26G T1 & 35.3 & 2.7 & 34.6 & 3.2 & \(-\)0.7 & & \\ \hline
16-26G T1-T0 & 1.1 & 1.3 & 2.4 & 1.4 & 1.3 & \(<\)0.01 * & T0 vs. T1 \\ \hline Rotation MRA 16/26 & \(-\)28.4 & 3.2 & \(-\)15.1 & 1.6 & 13.3 & \(<\)0.01 * & T0 vs. T1 \\ \hline Inclination 16/26 & \(-\)6.5 & 3.8 & \(-\)3.1 & 4.1 & 3.4 & \(<\)0.01 * & T0 vs. T1 \\ \hline \end{tabular}
\end{table} 
Table 1: Mean results of the measurements done on both samples. Statistically significant values (\(p<0.05\)) are marked with (*). For the first permanent molars it was observed a 3.2 \(\pm\) 1.2 mm dental expansion for the IF cases and 4.4 \(\pm\) 1.4 mm for the LE cases, whereas gingivally a 1.1 \(\pm\) 1.3 mm expansion was noted for the IF cases and 2.4 \(\pm\) 1.4 for the LE cases. As for the first deciduous molars, a 4.8 \(\pm\) 1.7 mm dental expansion was obtained in the IF cases and a 5.5 \(\pm\) 1.8 mm dental expansion in the LE cases. Gingivally, a 2.8 \(\pm\) 2.0 mm expansion for the IF cases and a 4.1 \(\pm\) 1.5 mm for the LE cases were noted. As for the second deciduous molars a 4.5 \(\pm\) 1.6 mm dental expansion for the IF cases and 5.2 \(\pm\) 1.5 mm for the LE cases was found. Gingivally it was observed a 2.4 \(\pm\) 1.8 expansion for the IF cases and a 4.5 \(\pm\) 1.6 mm for the LE cases. These results are displayed in Figure 3.  
The  
Figure 4: Expansion Clear difference between Invaslign First and Leaf Expander. Statistically significant values are marked with (*).