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.