Towards patient-specific optimization for mandibular reconstruction planning based on predicted bone-union propensity

Mandibular reconstruction with vascularized bone grafts is complicated by donor-host nonunion, and current virtual surgical planning produces a geometric plan rather than optimizing for bone-union propensity at the donor-host interface. We present OsteoOpt++, an image-to-decision planning loop for patient-specific mandibular reconstruction. A pre-operative computed tomography (CT) is converted into a personalized digital twin through template-to-patient registration and CT-derived updates of the muscle and temporomandibular-joint parameters. Bayesian optimization with an expected-improvement-plus acquisition rule then searches six clinically controllable cut-plane and donor-positioning variables under an apposition-driven objective and a safety-factor-regularized variant. The workflow was evaluated on three generic defects (body, symphysis, and ramus-body) and four patient-specific cases, three of which were used for optimization and all four for retrospective longitudinal spatial analysis. In the generic cases, against the surgeon's geometric plan, cycle-averaged donor-mandible apposition increased by up to 29 percentage points; in the patient-specific cases, against the surgeon-implemented day-5 postoperative configuration, by up to 26 percentage points. A ±10% sensitivity analysis over eleven modeling parameters capped the change in the apposition-driven objective at ∼3% (generic) and ∼4% (patient-specific), and across the four longitudinal cases the Dice overlap between predicted apposition and year-1 bone formation ranged from 70.1% to 84.9%, with centroid shifts of 0.24 to 1.82 mm. Together, these results support the feasibility-stage use of OsteoOpt++ to compare candidate reconstructions using apposition-derived predictions of bone-union propensity. The optimization and patient-specific modeling code is open source at https://github.com/hamidreza-aftabi/OsteoOpt.