An Anatomic Analysis of Fibula Flap Mandible Reconstructions: Implications for Endosseous Implant Placement

Background: Precise planning and evaluation of the fibula bone are necessary if immediate endosseous implant placement is considered. Limited information is available on the anatomical dimensions or density of fibula used in mandibular reconstructions. This study aimed to describe the morphology and dimensions of the fibula used to reconstruct segmental mandibular defects and contrast the findings with the native mandible. Methods: A retrospective analysis was performed of patients who underwent segmental mandibulectomy reconstructed with osteocutaneous fibula flaps and had at least one postoperative computed tomography scan. Fibula cross sectional dimensions and densities were evaluated with three-dimensional software. Radiographic measurements were obtained from the contralateral mandible medial to the first molar for comparison. Results: Four hundred seventy-seven fibula cross sections from 159 segments were evaluated. Cross-sectional oval, quadrilateral, triangular, and pentagonal shapes differed significantly in proportion ( p < 0.001). Thirty-eight percent of segments (95 percent CI, 30 to 46 percent) had differences in cross-section height greater than 1 mm ( p < 0.001). Between segments within the same patient, the median height difference was 1.58 mm (range, 0.14 to 6 mm). The superior cortex density was significantly higher for the fibula than the native mandible; however, the medullary space density was significantly lower ( p < 0.001). Conclusions: The current study comprises the most comprehensive description of fibula morphology in mandibular reconstructions and highlights the significant variability that exists. The findings provide justification for the added time and cost of computer-aided design and computer-aided manufacturing in centers interested in performing immediate dental implant placement, as the technology provides the necessary precision and accuracy.