## 5 Discussion  
As described in the literature, tooth-borne expanders produce a V-shaped opening of the midpalatal suture, with the greatest opening anteriorly and progressively less separation toward its posterior part [12; 13; 14; 15]. [PERSON] et al. [14] used a tooth-borne maxillary expander activated by 7 mm on all patients and found that the opening of the midpalatal suture was 3.01 and 1.15 mm at the ANS and PNS, respectively. Conversely, in the patients treated with MARPE in our present study, the borders of the midpalatal suture moved almost perfectly parallel to each other, as evidenced by the amount of split at the PNS, which was 85% of that at the ANS. Although some authors recommended classic orthodontic treatment in young adult patients with transverse maxillary deficiencies, the failure rate in such cases can be high [16]. Performing an initial cone-beam computed tomography (CBCT) examination is crucial in limiting therapeutic failure in patients undergoing MARPE. The advantage of this method is that it provides important details about the local anatomy, the thickness of the palatine bone, and anatomical details about the articulation of the palatine bone with the pterygoid process to the sphenoid bone. This allows proper planning of this orthodontic treatment. Knowledge of local anatomical details plays a particularly important role in these cases [17; 18]. Analyzing the transverse asymmetry of the mid-palatal split (Table 1), on average, one-half of the ANS moved more than the contralateral one by 0.89 mm. The reason for this is unclear but could be related to external forces, such as the presence of a unilateral crossbite that hampers the movement of one maxilla. [PERSON] et al. [19] published a comparative study between tooth-borne and bone-borne MARPE on late adolescents. The MARPE used in their study included four micro-implants embedded in two acrylic shelves supporting the jackscrew. All implants were positioned close to the dentition, inferiorly from the mid-palatal suture, but the appliance did not \begin{table}
\begin{tabular}{c c c} \hline
**D’Agnostino \& Pearson** & **1 st Molar Tilt after** & **1 st Molar Tilt before** \\
**Omnibus Normality Test** & **Treatment** & **Treatment** \\ \hline Std. Error of Mean & 0.2238 & 0.2363 \\ \hline Lower 95 \% CI of mean & 87.41 & 85.38 \\ \hline Upper 95 \% CI of mean & 88.34 & 86.36 \\ \hline
**Table Analyzed** & **Data 1** \\ \hline Column B & 1 st Molar tilt before treatment \\ \hline Vs. & Vs. \\ \hline Column A & 1 st Molar tilt after treatment \\ \hline Paired \(t\) test & \\ \hline \(p\) value & \(<\) 0.0001 \\ \hline \(p\) value summary & \\ \hline Significantly different? (\(p<0.05\)) & yes \\ \hline One- or two-tailed \(P\) value & Two-tailed \\ \hline \(t\), df & \(t=12.33\) df = 19 \\ \hline Number of pairs & 40 \\ \hline How big is the difference & \(-2.005\) \\ \hline SD of differences & 0.7273 \\ \hline SEM of differences & 0.1626 \\ \hline
95\% confidence interval & \(-2.345\) to \(-1.665\) \\ \hline R square & 0.8889 \\ \hline \end{tabular}
\end{table} 
Table 4: _Cont._contact the dentition. Angular measurements were performed to assess alveolar bone bending and dental tipping using an arbitrary palatal plane. Significant alveolar bone bending and dental tipping even with this bone-borne expander treatment were found. The dentoalveolar changes may have been possible because of the force applied to the dentoalveolar region by this appliance; however, it is difficult to accept that dental movement could occur even though the expander did not have any physical contact with the dentition. This implies that angular measurements from arbitrary points cannot accurately assess the true impact of an appliance. The activation force of a rapid maxillary expander (RME) device initially results in the compression of the periodontal ligament, bending of the alveolar bone, and tipping of the anchored teeth [20].