## 3 Results
### Comparison of Dentoulveolar Width Changes Between the Two Groups  
After treatment, an independent samples _t_-test was conducted to compare dental changes achieved between the two groups (Table 2). While the majority of variables showed no significant differences, significant changes were identified in specific areas of the lower arch: in the cusps between second premolars (mean difference: 1.50 mm, \(p\) = 0.016), favoring the CA group; and in the cervical regions between teeth first premolars (mean difference: 1.00 mm, \(p\) = 0.008), and second premolars (mean difference: 1.13 mm, \(p\) = 0.010), where the CA group exhibited greater expansion compared to the GT group too. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Outcome**} & \multicolumn{2}{c}{**GT**} & \multicolumn{2}{c}{**CA**} & \multicolumn{2}{c}{**Mean Diff**} & \multicolumn{2}{c}{**95\%CI**} & \multirow{2}{*}{_p_ **(sig)**} \\ \cline{2-2} \cline{5-8}  & **Mean GT** & **SD GT** & **Mean CA** & **SD CA** & & & **Upper** & **Lower** \\ \hline Real\_13\_23\_cusp & 1.60 & 2.20 & 1.02 & 1.09 & \(-\)0.58 & 0.54 & \(-\)1.70 & 0.298 \\ Real\_14\_24\_cusp & 2.78 & 2.03 & 2.44 & 1.40 & \(-\)0.35 & 0.77 & \(-\)1.46 & 0.533 \\ Real\_15\_25\_cusp & 2.45 & 1.71 & 2.42 & 1.81 & \(-\)0.03 & 1.09 & \(-\)1.16 & 0.950 \\ Real\_13\_23\_cerv & 0.88 & 1.25 & 0.96 & 0.82 & 0.08 & 0.75 & \(-\)0.60 & 0.820 \\ Real\_14\_24\_cusp & 1.66 & 1.28 & 1.67 & 0.91 & 0.01 & 0.73 & \(-\)0.70 & 0.966 \\ Real\_15\_25\_cerv & 1.37 & 1.13 & 1.50 & 1.34 & 0.13 & 0.92 & \(-\)0.66 & 0.740 \\ Real\_33\_cusp & 0.81 & 1.41 & 0.18 & 1.33 & \(-\)0.64 & 0.24 & \(-\)1.52 & 0.150 \\ Real\_34\_44\_cusp & 1.26 & 1.88 & 2.34 & 1.64 & 1.07 & 2.20 & \(-\)0.06 & 0.062 \\ Real\_35\_45\_cusp & 1.44 & 1.60 & 2.94 & 2.14 & 1.50 & 2.71 & 0.29 & 0.016 \\ Real\_34\_33\_covery & 0.28 & 0.79 & 0.62 & 0.99 & 0.34 & 0.91 & \(-\)0.23 & 0.235 \\ Real\_34\_44\_cerv & 0.83 & 1.09 & 1.83 & 1.17 & 1.00 & 1.72 & 0.27 & 0.008 \\ Real\_35\_45\_cerv & 0.80 & 0.99 & 1.93 & 1.59 & 1.13 & 1.98 & 0.28 & 0.010 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Comparison of dentoulveolar width changes (Real) between GT (Geniova) and CA (clear aligner) groups. SD: Standard deviation; Diff: difference; CI: confidence interval; sig: significance; 13\_23: upper canines; 14\_24: upper first premolars; 15\_25: upper second premolars; 33\_43: lower canines; 34\_44: lower first premolars; 35\_55: lower second premolars; cusp: cuspid level; cerv: cervical level. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Outcome**} & \multicolumn{2}{c}{**GT**} & \multicolumn{2}{c}{**CA**} & \multicolumn{2}{c}{**95\%CI**} & \multirow{2}{*}{_p_ **(sig)**} \\ \cline{2-2} \cline{5-8}  & **Mean GT** & **SD GT** & **Mean CA** & **SD CA** & & & **Upper** & **Lower** \\ \hline \multirow{2}{*}{
\begin{tabular}{c} Real\_13\_23\_cusp \\ Real\_14\_24\_cusp \\ Real\_15\_25\_cusp \\ \end{tabular} } & 1.60 & 2.20 & 1.02 & 1.09 & \(-\)0.58 & 0.54 & \(-\)1.70 & 0.298 \\ Real\_14\_24\_cusp & 2.78 & 2.03 & 2.44 & 1.40 & \(-\)0.35 & 0.77 & \(-\)1.46 & 0.533 \\ Real\_15\_25\_cusp & 2.45 & 1.71 & 2.42 & 1.81 & \(-\)0.03 & 1.09 & \(-\)1.16 & 0.950 \\ Real\_13\_23\_cerv & 0.88 & 1.25 & 0.96 & 0.82 & 0.08 & 0.75 & \(-\)0.60 & 0.820 \\ Real\_14\_24\_cusp & 1.66 & 1.28 & 1.67 & 0.91 & 0.01 & 0.73 & \(-\)0.70 & 0.966 \\ Real\_15\_25\_cerv & 1.37 & 1.13 & 1.50 & 1.34 & 0.13 & 0.92 & \(-\)0.66 & 0.740 \\ Real\_33\_cusp & 0.81 & 1.41 & 0.18 & 1.33 & \(-\)0.64 & 0.24 & \(-\)1.52 & 0.150 \\ Real\_34\_44\_cusp & 1.26 & 1.88 & 2.34 & 1.64 & 1.07 & 2.20 & \(-\)0.06 & 0.062 \\ Real\_35\_45\_cusp & 1.44 & 1.60 & 2.94 & 2.14 & 1.50 & 2.71 & 0.29 & 0.016 \\ Real\_33\_43\_covery & 0.28 & 0.79 & 0.62 & 0.99 & 0.34 & 0.91 & \(-\)0.23 & 0.235 \\ Real\_34\_44\_cerv & 0.83 & 1.09 & 1.83 & 1.17 & 1.00 & 1.72 & 0.27 & 0.008 \\ Real\_35\_45\_cerv & 0.80 & 0.99 & 1.93 & 1.59 & 1.13 & 1.98 & 0.28 & 0.010 \\ \hline \hline \end{tabular}
\end{table}