Impact of osteotomy angle on bone failure risk in a modified pull-through approach: a finite element analysis

Background: A modified pull-through approach represents a promising treatment strategy to access tumors in the posterior oral cavity. The design of the wedge osteotomy plays a key role in preserving postoperative mechanical stability while enabling surgical access. However, the optimal osteotomy design to reduce fracture risk remains unclear. Therefore, this study aimed to test osteotomy wedge designs that have the potential to lower the bone fracture risk. Methods: Four wedge osteotomy configurations were compared using finite element analysis based on a realistic mandible model. Each design differed in the angles and curvature of the osteotomy planes. Unilateral molar clenching was simulated, and mechanical strains were quantified and compared to the yield strain of cortical bone in the canine region to evaluate the risk of bone failure. Results: The finite element analysis showed that a wedge osteotomy with less acute angles in the canine region has a lower fracture risk when compared to osteotomies with sharp angles. Peak bone strain values could be reduced by half by changing the osteotomy angle at the canine region. Conclusions: A larger angle between the osteotomy cutting planes offers mechanical advantages by reducing strain concentrations in critical regions. These findings provide valuable guidance for refining the current surgical technique and support the integration of biomechanical analyses into osteotomy planning to optimize surgical outcomes.