## 3 Results
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Independent Variable** & **B** & **Odds Ratio** & \(p\)**-Value** \\ \hline Age & \(-\)0.140 & 0.869 & 0.019 \\ Sex * & \(-\)3.804 & 0.022 & 0.002 \\ A-N perp & 0.464 & 1.591 & 0.015 \\ Rickett’s LFH & 0.234 & 1.264 & 0.084 \\ \hline \hline \end{tabular}  
*Odds ratio of males compared to females. A-N perp: distance from point A to nasion perpendicular line. Rickett’s LFH: Rickett’s lower facial height.  
\end{table} 
Table 4: Factors associated with success of microimplant-assisted rapid palatal expansion. (Dependent variable: success [1] or failure [0]). \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Variables** & **T1** & **T2** & \(p\)**-Value** \\ \hline SNA (\({}^{\circ}\)) & 81.2 \(\pm\) 3.8 & 82.5 \(\pm\) 3.6 & \(<\)0.001 \\ SNB (\({}^{\circ}\)) & 80.9 \(\pm\) 3.6 & 80.8 \(\pm\) 3.7 & 0.725 \\ ANB (\({}^{\circ}\)) & 0.3 \(\pm\) 3.2 & 1.6 \(\pm\) 2.8 & 0.001 \\ A-N perp (mm) & 0.6 \(\pm\) 3.4 & 1.1 \(\pm\) 3.2 & \(<\)0.001 \\ SN-MP (\({}^{\circ}\)) & 34.3 \(\pm\) 4.7 & 35.6 \(\pm\) 4.7 & 0.001 \\ Overbite (mm) & 0.3 \(\pm\) 2.0 & \(-\)0.5 \(\pm\) 1.8 & 0.009 \\ Overjet (mm) & 1.6 \(\pm\) 2.3 & 2.1 \(\pm\) 2.4 & 0.091 \\ Rickett’s LFH (mm) & 48.4 \(\pm\) 4.2 & 49.6 \(\pm\) 4.2 & 0.002 \\ SNA (\({}^{\circ}\)) & 81.2 \(\pm\) 3.8 & 82.5 \(\pm\) 3.6 & \(<\)0.001 \\ \hline \hline \end{tabular}  
* SNA: Sella-nasion point A, SNB: Sella-nasion point B. A-N perp: Distance from point A to nasion perpendicular. SN-MP: Mandibular-plane angle defined as the angle between the sella-nasion plane and the mandibular plane. Rickett’s LFH: Rickett’s lower facial height.  
\end{table} 
Table 2: Comparison of the cephalometric variables before (T1) and after (T2) microimplant-assisted rapid palatal expansion. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{2}{c}{**F Group**} & **S Group** \\ \cline{2-4}  & **(\(n\) = 15)** & **(\(n\) = 41)** & \(p\)**-Value** \\ \hline Sex & Male & 13 & 16 \\  & Female & 2 & 25 \\ \hline Appliance type & Hyrax & 3 & 7 \\  & MSE & 12 & 34 \\ \hline Fixation & Monocortical & 6 & 10 \\  & Bicortical & 6 & 20 \\ \hline \hline \end{tabular}  
* CVMI: Cervical-vertebrae maturation index. Hyrax: A modified Hyrax expander with soldered holes for microimplant placement on the palate and banded to the premolars and molars. MSE: Maximillary skeletal expander (MSE, Biomaterial Korea, Seoul, Korea) that has holes for microimplants incorporated in the expander and banded to the molars.  
\end{table} 
Table 3: Patient distribution of the success (S) and failed (F) groups according to sex, CVMI, type of appliance, and mode of fixation. With the use of MARPE, the mean amounts of expansion in the nasal cavity, zygomatomaxillary suture, maxillary bone at the level of the roof of the palate, and bone between the function of the upper molars were 2.0 \(\pm\) 0.9 mm, 2.2 \(\pm\) 1.0 mm, 2.6 \(\pm\) 1.6 mm, and 2.9 \(\pm\) 1.2 mm, respectively. The factors showing significant association with the amount of maxillary skeletal expansion were MPSD at T1 and SN-MP at T1 (Table 5). The correlation coefficients indicated that higher SN-MP and lower MPSD at pretreatment were associated with a greater amount of skeletal expansion following MARPE.