# Effect of the Mandibular Repositioning Appliance (MARA) on Posterior Airway Space (PAS)
## 3 Results  
With regard to the PAS, it was found that, averaged over all the patients in the two groups, the two-dimensional, anteroposterior diameter of the PAS increased, but the increase was greater in the male patients (+27.5%) than in the female patients (+11.6%). A significant increase in the PAS was found in the male patients (\(p\) = 0.006) but not in the female patients (\(p\) = 0.09) (see Table 3a). Some patients (N = 7) showed a decrease in the PAS (maximum \(-\)1.2 mm). In the male patients, this only occurred in one case (\(-\)0.5 mm). This is probably due to the smaller average PAS increase in female patients. To verify this, decreases in the PAS (i.e., negative differences by subtracting the PAS measured in T2 from the PAS measured in T1) were considered to be outliers. This resulted in significant changes in the PAS for both groups: +29.2% (\(p\) = 0.005) and +17.8% (0.044) (see Table 3b). The following provides concise and precise descriptions and interpretations of the experimental results. Additional cephalometric parameters were obtained from the lateral cephalograms. Table 4 shows Bjork's sum angle. This parameter decreased in both groups but not significantly (\(p\) = 0.78, \(p\) = 0.86). Overall, the male patients showed a greater decrease between T1 and T2 than the female patients. Apparently, unspecified individual factors contributed to this development, other than the MARA alone, resulting in more heterogeneous inter-individual values. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Group** & **PAS T1** & **PAS T2** & \(\Delta\)**PAS Abs.** & \(\Delta\)**Rel.** \\ \hline \multicolumn{5}{c}{(a)} \\ \hline
1 & 10.53 \(\pm\) 3.4 mm & 13.42 \(\pm\) 3.8 mm & 2.9 \(\pm\) 2.05 mm & 27.5\% \(p\) = 0.006 \\ \hline
2 & 11.25 \(\pm\) 2.7 mm & 12.55 \(\pm\) 2.9 mm & 1.3 \(\pm\) 0.92 mm & 11.6\% \(p\) = 0.090 \\ \hline Average & 10.89 mm & 12.99 mm & 2.1 mm & - \\ \hline
[20] & 13.27 \(\pm\) 3.07 mm & 12.86 \(\pm\) 2.47 mm & \(-\)0.4 \(\pm\) 2.58 mm & \(p\) = 0.5155 \\ \hline \multicolumn{5}{c}{(b)} \\ \hline
1 (N = 25) & 10.36 \(\pm\) 3.35 mm & 13.39 \(\pm\) 3.90 mm & 3.03 \(\pm\) 2.14 mm & 29.2\% \(p\) = 0.005 \\ \hline
2 (N = 20) & 10.95 \(\pm\) 2.86 mm & 12.90 \(\pm\) 3.06 mm & 1.95 \(\pm\) 1.38 mm & 17.8\% \(p\) = 0.044 \\ \hline \end{tabular}
\end{table} 
Table 3: (a) PAS, raw data; (b) PAS, without outliers. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Group** & **SNB T1** & **SNB T2** & **\(\Delta\)****SNA** & **\(\Delta\)****S****Rel.** \\ \hline
1 & 77.31 \(\pm\) 4.8\({}^{\circ}\) & 77.63 \(\pm\) 4.7\({}^{\circ}\) & 0.32 \(\pm\) 0.23\({}^{\circ}\) & 0.41\% \(p\) = 0.810 \\ \hline
2 & 75.98 \(\pm\) 3.9\({}^{\circ}\) & 76.08 \(\pm\) 4.3\({}^{\circ}\) & 0.10 \(\pm\) 0.07\({}^{\circ}\) & 0.13\% \(p\) = 0.930 \\ \hline
[20] & 74.6 \(\pm\) 4.99\({}^{\circ}\) & 75.89 \(\pm\) 5.12\({}^{\circ}\) & +1.29 \(\pm\) 1.34\({}^{\circ}\) & \(p\) = 0.0008 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: SNB. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Group** & **SNB T1** & **SNB T2** & **\(\Delta\)****SNA** & **\(\Delta\)****Rel.** \\ \hline
1 & 388.31 \(\pm\) 7.0\({}^{\circ}\) & 387.74 \(\pm\) 7.9\({}^{\circ}\) & \(-\)0.57 \(\pm\) 0.07\({}^{\circ}\) & \(-\)0.15\% \(p\) = 0.780 \\ \hline
2 & 393.18 \(\pm\) 7.4\({}^{\circ}\) & 392.83 \(\pm\) 7.6\({}^{\circ}\) & \(-\)0.36 \(\pm\) 0.25\({}^{\circ}\) & \(-\)0.09\% \(p\) = 0.860 \\ \hline
[20] & 392.96 \(\pm\) 9.02\({}^{\circ}\) & 392.07 \(\pm\) 8.85\({}^{\circ}\) & \(-\)0.89 \(\pm\) 3.27\({}^{\circ}\) & \(p\) = 0.262 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Sum angle [[PERSON]’s sum angle].