Beyond the osteotomy: a preliminary computational framework for biomechanical complexity assessment in midfacial distraction osteogenesis

Virtual surgical planning for midfacial distraction osteogenesis relies on static, bone-only assumptions that neglect callus and soft tissue biomechanics. This study presents a finite element framework quantifying these factors and proposes an exploratory Distraction Osteogenesis Complexity Score. A patient-specific model (849,921 elements) simulated 18 scenarios across Le Fort I–III osteotomies with varying callus stiffness and soft tissue conditions, quantifying rotation complexity, anterior translation gain, and strain risk. Scores ranged from 2.01 to 7.75 (mean 4.66 ± 1.98) and increased with osteotomy level, though overlap indicated level alone is insufficient. Standard planning underestimated displacement requirements by 59% for Le Fort III during early healing. Prospective clinical validation is required.