Deferoxamine Enhances the Vascular Response of Bone Regeneration in Mandibular Distraction Osteogenesis

Bone regeneration during distraction osteogenesis is intricately associated with an enhanced vascular response. Augmenting this response may offer considerable clinical advantages such as optimizing the quality of regenerate formation, decreasing lengthy consolidation periods, or increasing regenerate size and distance. Using deferoxamine, an angiogenic transcriptional activator, the authors posit that substantial increases in vascular volume beyond the normal response to mechanical distraction can be quantified with micro-computed tomography after vessel perfusion during mandibular distraction osteogenesis. Two groups of Sprague-Dawley rats (n = 12) underwent external fixator placement, mandibular osteotomy, and 5.1-mm distraction. During distraction, the experimental group (n = 6) was treated with deferoxamine injections into the distraction gap. After consolidation, the animals were perfused and imaged with micro-computed tomography. Vascular radiomorphometrics were calculated and statistical comparison was conducted with the independent samples t test. A value of p ≤ 0.05 was considered statistically significant. A 40 percent statistically significant increase in the number of vessels (0.82 vessels/mm versus 1.15 vessels/mm; p < 0.012) and a complementary decrease in the space between vessels (1.18 mm versus 0.86 mm; p < 0.012) were calculated in the experimental regenerate when compared with controls. This robust increase in vascularity could also be readily observed with micro-computed tomographic image reconstruction. Gross examination revealed a denser regenerate in the deferoxamine-injected group that is clearly illustrated with Faxitron radiography. The authors' study quantifies the ability of deferoxamine to augment the vascular response of mandibular distraction osteogenesis and establishes correlations between this therapeutic enrichment and enhanced regenerate formation.