Dentoskeletal Outcomes of Two Digitally Designed Bone-Borne MARPE Approaches: A Three-Dimensional CBCT Study

Miniscrew-assisted rapid palatal expansion (MARPE) is increasingly used to manage transverse maxillary deficiency; however, three-dimensional evidence comparing bone-borne appliance designs remains limited. This retrospective cone-beam computed tomography (CBCT) study evaluated the dentoskeletal outcomes of two digitally planned MARPE approaches using Superscrew- and Hyrax-type expansion screw systems. Because activation regimen was associated with the screw system, the groups were interpreted as two clinical approaches rather than isolated screw-design comparisons. Twenty-seven individuals were divided into Superscrew-type (n = 15) and Hyrax-type (n = 12) groups. Pretreatment and post-expansion CBCT records were used to assess midpalatal and pterygopalatine suture opening, nasal and maxillary width changes, and buccal and palatal intermolar distances. Both approaches produced significant increases in nasal, maxillary, and intermolar widths. No significant intergroup differences were observed in sutural opening, PNS/ANS ratio, pterygopalatine suture separation, nasal width, maxillary width, or buccal intermolar distance changes. A borderline unadjusted difference was observed for palatal intermolar distance (6.08 ± 2.48 mm vs. 4.29 ± 1.97 mm; unadjusted p = 0.047), but it did not remain significant after correction for multiple comparisons. Therefore, this finding should be interpreted as exploratory rather than clinically confirmatory.