## 3 Results
### Expansion Predictability
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{2}{c}{**Within-Group Comparisons T3-T1**} & \multicolumn{2}{c}{**Mean \(\pm\) SD**} & \multicolumn{2}{c}{**T3-T1 (mm)**} & \multicolumn{2}{c}{**95\%CI**} & \multicolumn{1}{c}{\(p\)**-Value**} & \multicolumn{1}{c}{**T3-T1 (\%)**} \\ \hline \multirow{8}{*}{Unilateral Crossbite} & \multirow{2}{*}{Canine} & T1: PRE & 33.58 \(\pm\) 2.95 & \multirow{2}{*}{\(-\)0.14} & \multirow{2}{*}{\(-\)1.37 to 1.65} & \multirow{2}{*}{1} & \multirow{2}{*}{\(-\)0.42\%} \\ \cline{3-4} \cline{6-7}  & & T3: POST & 33.44 \(\pm\) 1.74 & & & & \\ \cline{2-7}  & 1 st & T1: PRE & 39.65 \(\pm\) 2.49 & \multirow{2}{*}{1.65} & \multirow{2}{*}{\(-\)2.76 to \(-\)0.55} & \multirow{2}{*}{0.004} & \multirow{2}{*}{4.16\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{Premolar} & T3: POST & 41.30 \(\pm\) 2.44 & & & & \\ \cline{2-7}  & 2 nd & T1: PRE & 44.32 \(\pm\) 2.60 & \multirow{2}{*}{2.54} & \multirow{2}{*}{\(-\)3.99 to \(-\)1.10} & \multirow{2}{*}{0.001} & \multirow{2}{*}{5.75\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{1 st Molar} & T3: POST & 46.87 \(\pm\) 1.99 & & & & \\ \cline{2-7}  & 1 st Molar & T1: PRE & 48.85 \(\pm\) 2.65 & \multirow{2}{*}{2.08} & \multirow{2}{*}{\(-\)3.35 to \(-\)0.81} & \multirow{2}{*}{0.002} & \multirow{2}{*}{4.26\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{Canine} & T3: POST & 50.93 \(\pm\) 2.08 & & & & \\ \hline \multirow{8}{*}{Bilateral Crossbite} & \multirow{2}{*}{Canine} & T1: PRE & 32.37 \(\pm\) 2.56 & \multirow{2}{*}{0.91} & \multirow{2}{*}{\(-\)3.08 to \(-\)0.29} & \multirow{2}{*}{0.016} & \multirow{2}{*}{2.81\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{T3: POST} & T3: POST & 33.28 \(\pm\) 1.89 & & & & \\ \cline{2-7}  & 1 st & T1: PRE & 37.82 \(\pm\) 3.10 & & & & \\ \cline{2-7}  & 1 st & T3: POST & 41.21 \(\pm\) 2.69 & \multirow{2}{*}{3.38} & \multirow{2}{*}{\(-\)4.91 to \(-\)1.86} & \multirow{2}{*}{\(<\)0.001} & \multirow{2}{*}{8.96\%} \\ \cline{3-4} \cline{6-7}  & 2 nd & T1: PRE & 41.53 \(\pm\) 3.95 & \multirow{2}{*}{4.86} & \multirow{2}{*}{\(-\)6.84 to \(-\)2.87} & \multirow{2}{*}{\(<\)0.001} & \multirow{2}{*}{11.70\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{T3: POST} & T3: POST & 46.39 \(\pm\) 3.17 & & & & \\ \cline{2-7}  & 1 st & T1: PRE & 46.35 \(\pm\) 3.16 & \multirow{2}{*}{3.95} & \multirow{2}{*}{\(-\)5.33 to \(-\)2.58} & \multirow{2}{*}{\(<\)0.001} & \multirow{2}{*}{8.52\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{Molar} & T3: POST & 50.30 \(\pm\) 3.20 & & & & \\ \hline \multirow{8}{*}{Canine} & T1: PRE & 32.19 \(\pm\) 1.81 & \multirow{2}{*}{1.01} & \multirow{2}{*}{\(-\)1.82 to \(-\)0.20} & \multirow{2}{*}{0.013} & \multirow{2}{*}{3.14\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{T3: POST} & T3: POST & 33.20 \(\pm\) 2.10 & & & & \\ \cline{2-7}  & 1 st & T1: PRE & 37.64 \(\pm\) 3.13 & \multirow{2}{*}{3.02} & \multirow{2}{*}{\(-\)4.17 to \(-\)1.88} & \multirow{2}{*}{\(<\)0.001} & \multirow{2}{*}{8.05\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{T3: POST} & T3: POST & 40.67 \(\pm\) 2.53 & & & & \\ \cline{2-7}  & 2 nd & T1: PRE & 42.59 \(\pm\) 3.56 & \multirow{2}{*}{3.41} & \multirow{2}{*}{\(-\)4.63 to \(-\)2.19} & \multirow{2}{*}{\(<\)0.001} & \multirow{2}{*}{8.01\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{T3: POST} & T3: POST & 46 \(\pm\) 2.91 & & & & \\ \cline{2-7}  & 1 st Molar & T1: PRE & 47.10 \(\pm\) 3.69 & \multirow{2}{*}{2.67} & \multirow{2}{*}{\(-\)4.03 to \(-\)1.30} & \multirow{2}{*}{\(<\)0.001} & \multirow{2}{*}{5.67\%} \\ \cline{3-4} \cline{6-7}  & \multirow{2}{*}{T3: POST} & T3: POST & 49.77 \(\pm\) 3.53 & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Within-group comparisons of the efficacy (T3-T1) of expansion at canine, premolar, and molar levels. T1: pretreatment width; T3: post-treatment width; T3-T1(%): percentage of initial width increased by treatment. SD: standard deviation, %: percentage, CI: confidence interval, PRE: pre-treatment measure, POST: post-treatment measure, T3: actual end-expansion achieved, T1: beginning, mm: millimeters.