## 4 Discussion  
Rapid palatal expansion is slightly more effective in increasing the posterior transverse skeletal width of the maxilla, while slow palatal expansion induces less molar inclination [35]. On the other hand, patients who underwent slow palatal expansion reported significantly less pain than those treated with rapid palatal expansion during the first week of treatment, although no notable differences in pain levels were found between the two protocols thereafter [36]. Additionally, RPE may temporarily affect articulation of certain sounds during expansion, but these changes usually resolve after appliance removal [37]. According to a recent meta-analysis, MARPE is regarded as an effective modality for treating maxillary transverse deficiency, as it achieves considerable skeletal expansion in late adolescence. In contrast, it demonstrates fewer detrimental periodontal effects and certain clinical benefits compared to CRPE [38]. A recent review article suggests that the success rate of MARPE may decline in males beyond their mid-20s, while favorable outcomes can still be achieved in females into their mid-30s [39]. Similarly, the Delphi consensus reported that the likelihood of midpalatal suture opening decreases after the mid-20s, particularly in males. However, the panel did not reach a consensus on whether bone-anchored expanders produce greater skeletal expansion or lead to more stable medium- or long-term outcomes in growing patients [40]. Several studies in growing patients have reported that MARPE produces a skeletal-to-dental expansion ratio nearly twice as high as that of CRPE [13,33]. A CBCT-based study in growing patients reported that MARPE induced significant skeletal and dental expansion, with a more parallel midpalatal suture split compared to CRPE, consistent with previous findings [41]. MARPE was associated with greater long-term dentoskeletal stability and less relapse in transverse width compared to RPE, particularly in the premolar region after 10 years [42]. [PERSON] reported that significant interdigitation of the midpalatal suture occurs after puberty, based on histologic findings [9]. In addition, [PERSON] et al. established that the peak pubertal growth spurt generally occurs at CVM stage III, which typically corresponds to ages 11-14 [43]. Supporting this, [PERSON] et al. reported higher midpalatal suture opening success rates with MARPE in adolescents compared to adults, reinforcing the importance of skeletal rather than chronological age in patient selection [20]. This meta-analysis compared the dentoalveolar changes of MARPE and CRPE in growing patients. Overall, CRPE resulted in greater dental tipping and more pronounced buccal bone loss compared to MARPE. Similar trends were observed in both molars and premolars, with premolars exhibiting more buccal bone reduction. This observation may be explained by anatomical differences, as the buccal cortical plate in the premolar region tends to be thinner, and the supporting root morphology is generally less robust, making this area more susceptible to resorption under lateral forces. Furthermore, variations in palatal vault depth and arch morphology may contribute to localized stress concentration, further amplifying bone remodeling in the premolar area. These outcomes are interpreted as consequences of the differences in anchorage. MARPE, utilizing skeletal anchorage, enables more central expansion while minimizing buccal cortical bone resorption. These findings are consistent with previous studies that reported significantly less buccal bone loss with MARPE than with CRPE [13,44; 25]. Furthermore, dental tipping was substantially more severe in the CRPE groups across the studies, supporting the claim that tooth-borne expanders transfer lateral forces directly to anchor teeth, causing unwanted dental side effects. [PERSON] et al. also found that MARPE produced a more parallel opening of the midpalatal suture compared to CRPE, which may help explain the reduced dentoalveolar side effects [44].