Maxillary and Mandibular Changes with 3D-Guided Midpalatal Piezocorticotomy - Assisted MARPE in Adults: A Retrospective Longitudinal Study

Introduction. Despite the increasing success rate of MARPE in different age groups, the concern still exists regarding potential downward rotation of the maxillary complex and increase in the middle and lower anterior facial heights due to midfacial expansion. 3D-guided midpalatal piezocorticotomy (3D-GMP) assisted MARPE is intended to increase the success rate of MARPE in adults and eliminate the age and sex parameters as limitations along with improving outcomes of MARPE alone. Methods. This retrospective longitudinal study evaluated pre- and post-expansion lateral cephalometric radiographs following midfacial expansion with 3D- GMP MARPE. Images were rendered from the CBCTs of 80 adult patients with mean age 35.23 ± 8.76 years (male n = 28, female n = 52). Fifteen lateral cephalometric measurements were compared. Measurements included maxillary forward displacement, mandibular rotation, inclination of the maxillary plane, occlusal plane rotation, and linear measurements of the facial heights. Maxillary incisor position was measured relative to the maxillary plane. Results. The angles SNA, ANB, and the linear measurement A-Nperp(FH) differed significantly between stages T0 and T1 indicating forward maxillary base movement following intervention. Multivariate linear regression analysis of the PPA value showed that the only predictor of the post-expansion PPA is the pre-expansion value of the same parameter, while sex, age, ANB, and the amount of midpalatal separation were not significantly associated with post-expansion inclination of the maxillary plane. Risk analysis demonstrated risk reduction of the downward maxillary rotation following the 3D- GMP MARPE. Conclusions. 3D- guided midpalatal piezocorticotomy assited MARPE may offer advantages in decreasing the risk of downward maxillary rotation along with maxillary protraction in adults. Forward maxillary movement was shown to be one of the consistent outcomes of 3D- GMP MARPE which is augmented with increased amount of midpalatal separation in adult patients.