Three-dimensional morphological analysis of neocondyle bone growth after fibula free flap reconstruction

The aim of this retrospective study was to verify the three-dimensional morphological change in neocondyle bone growth after fibula free flap (FFF) reconstruction. The independent variables were age, sex, and diagnosis. Outcome variables included the direction and volume of neocondyle bone growth, and the time to a stable neocondyle following bone growth. The outcome variables were measured on postoperative computed tomography scans using iPlan 3.0. Of the 35 patients included, 25 showed neocondyle bone growth. The direction of neocondyle bone growth included the direction of lateral pterygoid traction (DLPT) and the direction towards the glenoid fossa (DGF). The bone growth of the neocondyle showed three patterns: only DLPT (eight patients), only DGF (two patients), and a combination of DLPT and DGF (15 patients). The average volume of bone growth in the 25 patients was 0.479 ± 0.380 cm³. The average volume of neocondyle bone growth was significantly greater in patients aged <18 years (0.746 ± 0.346 cm³) than in patients aged >18 years (0.219 ± 0.191 cm³) (P < 0.001). The time to a stable neocondyle following bone growth was 5.6 months postoperatively. In conclusion, neocondyle bone growth after FFF reconstruction occurred in two different directions, DLPT and DGF. Osteogenesis of the lateral pterygoid muscle affects neocondyle growth with DLPT. Neocondyle bone growth is more marked in paediatric patients than in adults.