Minimally Invasive Surgical and Miniscrew‐Assisted Rapid Palatal Expansion ( <scp>MISMARPE</scp> ) – Immediate Skeletal and Dentoalveolar Effects With Tooth‐Bone‐Borne Versus Bone‐Borne Expanders: A Comparative Cohort Study

INTRODUCTION: This study evaluated the immediate skeletal and dentoalveolar effects of Minimally Invasive Surgical and Miniscrew Assisted Rapid Palatal Expansion (MISMARPE), comparing outcomes using two different appliance designs: tooth-bone-borne (TBB) and bone-borne (BB) expanders. METHODS: This retrospective comparative cohort study included 24 consecutively treated adult patients (mean age 35.9 ± 9.5 years): 13 in the TBB group and 11 in the BB group. Cone-beam computed tomography scans were obtained pre-treatment (T0) and immediately after expansion (T1) to assess skeletal and dentoalveolar changes. Generalized Estimating Equations analysis, followed by Bonferroni correction for multiple comparisons, was used to compare measurements between groups over time. RESULTS: The MISMARPE technique produced significant increases in all linear measurements except posterior maxillary basal width in the TBB group (p = 0.142). Both groups exhibited greater skeletal expansion in the anterior maxillary region, demonstrating a triangular expansion pattern in the axial view. The TBB group showed significantly greater increases in dental distances (6-6CR, p = 0.002; 6-6RT, p = 0.017) and posterior alveolar width (P-AM, p < 0.001) compared to the BB group. No significant changes in molar inclination were observed in either group post-expansion. CONCLUSIONS: The MISMARPE technique is effective for adult maxillary expansion, producing a triangular palatal expansion pattern in the axial view with parallel suture opening at the anterior nasal spine level in the coronal view. The TBB expander demonstrated greater transverse dentoalveolar expansion and stability of miniscrews compared to BB design, while both anchorage systems achieved similar skeletal effects.