Stress and Displacement Dynamics in Surgically Assisted Rapid Maxillary Expansion: A Comprehensive Finite Element...

Objectives: This study aimed to compare the effects of surgically assisted rapid palatal expansion (SARPE) techniques and their combinations on the stresses (von Mises, maximum principal, and minimum principal) and displacements that occur in the maxilla, facial bones, and maxillary teeth using three-dimensional finite element analysis (FEA). Methods: SARPE was simulated using seven different osteotomy techniques. The FEA models were simulated with a combination of various osteotomies, including midpalatal and lateral osteotomies, lateral osteotomy with a step, and separation of the pterygomaxillary junction. For each osteotomy variant, the instantaneous displacements and stresses resulting from forces applied by a 1 mm expansion of a tooth-borne appliance were evaluated. Results: Midpalatal osteotomy increased lateral displacement in the alveolar bone margins and intermaxillary suture while significantly reducing stresses around the intermaxillary suture. The addition of a pterygomaxillary osteotomy to the midpalatal and lateral osteotomies effectively reduced stresses in the posterior maxilla and cranial structures while enhancing lateral displacement. Although lateral osteotomy significantly reduced stresses in the midface, its effect on maxillary expansion was limited. Stepped lateral osteotomy had minimal effects on transverse displacement and stress reduction. Conclusions: Increasing the number of osteotomies reduced stress levels in the maxilla while enhancing lateral displacement. These results highlight the importance of selecting the most appropriate osteotomy technique to achieve optimal outcomes.