Distraction osteogenesis in irradiated rabbit mandibles with adjunctive hyperbaric oxygen therapy

Purpose: The purpose of this study was to evaluate the effect of hyperbaric oxygen therapy on bone regeneration during distraction of irradiated rabbit mandibles. Materials and Methods: Twenty New Zealand white rabbits were randomly sub-divided into 4 groups. Group 1 served as control, group 2 received preoperative radiation therapy, group 3 received pre- and postoperative hyperbaric oxygen (HBO) therapy, and group 4 received preoperative radiation therapy and pre- and postoperative HBO therapy. All rabbits underwent a corticotomy of the left body of the mandible after placement of a distraction device. Distraction, at a rate of 1 mm/day and a rhythm of 1 turn/day, began after a 3-day latency period for 14 days. Thirty days after completion of the distraction protocol, the animals were euthanized, and histomorphometric and radiographic data of the distraction segments were obtained. Results: Histomorphometric analysis of new bone fill was greatest in the non-irradiated groups compared to groups receiving radiation therapy, regardless of HBO therapy (P = .03). Pre-corticotomy bone density measurements showed a significant increase in bone density over time (P = .0007). This resulted in a significant relationship between HBO therapy, radiation therapy, and time (P = .0050). Conclusions: The results of the study support the use of HBO therapy during distraction osteogenesis. Any additional therapeutic benefit of HBO therapy in irradiated bone would require additional investigation.