Comparative evaluation of personalized 3D-printed scaffold-driven double-barrel fibula flap for the reconstruction of segmented mandibular defects

The challenge of reconstructing large mandibular bone defects with double-barrel fibula flap (DBFF) is limited by the availability of autogenous bone, which remains a significant issue in maxillofacial surgery. This study aims to compare the novel scaffold-driven double-barrel approach with the DBFF method, and investigate the biomechanical behavior of 3D-printed porous titanium scaffolds with varying design parameters. The mandibular reconstruction model underwent FEA in two surgery phases, under two experimental loads and two design parameters. The experimental scaffold design was categorized into 9 groups based on the porous diameters (D_P = 4 mm, 5 mm, 6 mm) and strut diameters (D_S = 0.4 mm,0.5 mm,0.6 mm). The results illustrated that the stress in fibula, cortical and trabecular bones for all groups were within the ranges of normal physiological levels. The porous scaffolds effectively transmit mechanical stimulation, resulting in bone graft materials achieving up to 99.9% strain, with low stiffness to avoid stress shielding. The study revealed that the design parameters of Group B and Group F were more conducive to meeting biomechanical demands and promoting bone regeneration. This study presents scientifically proven and effective clinical solution for restoring both function and aesthetics of mandibular defects, while also providing valuable insights for future design criteria in bone regeneration scaffolds.