Facial Symmetry Changes After Marpe For Mtd&Md Patients

To evaluate the effects of miniscrew-assisted rapid palatal expansion (MARPE) on facial symmetry changes in adults with maxillary transverse deficiency (MTD) and mandibular deviation (MD). This retrospective study approved by the Institutional Review Board (IRB-2023-045), analyzed 21 adults (9 males and 12 females, aging from 18-37 years old) with MTD and MD (Me to midsagittal plane(MSP) distance >4 mm) treated with MARPE. Patients’ Pre- and post-MARPE CBCT scans (T0/T1) were compared. Eighteen linear and angular parameters were analyzed and evaluated using paired t-tests (measurements between two sides of MSP; measurements of the same side between T0 and T1). Pearson’s correlation, multiple linear regression and path analysis assessed variable relationships. Pre-MARPE, maxillary transverse and vertical asymmetry coexisted with significant mandibular roll and yaw rotations toward the deviated side (p<0.05). Post-MARPE, vertical distance changes were more pronounced on the deviated side (p<0.05), while mandibular roll and yaw rotated toward the non-deviated side with reduced angles (p<0.05), accompanied by a 1.59±0.84 mm decrease in the Me-to-MSP distance (p<0.001). Path analysis revealed that asymmetric vertical maxillary changes indirectly correlated with mandibular deviation (MD) improvement (p<0.05). MARPE might improve facial symmetry in patients with MTD and MD by asymmetrical expansion effect and inducing compensatory mandibular rotation toward the non-deviated side. MARPE may offer the potential to improve facial asymmetry.