Effects of radiation therapy on reconstruction of mandibular defects with a titanium reconstruction plate

Titanium fixation plates are commonly used in reconstruction of mandibular defects resulting from tumor resections in head and neck surgery. The effects of radiation therapy on the interface of bone, plate, and soft tissue were examined in this in vivo study. Four conditioned beagles had 1-cm segmental mandibular defects that were reconstructed with titanium plates. Two of the four also had placement of vascularized bone grafts. Healing was evaluated with or without postoperative radiotherapy. After collection of tissues using histologic methods and analysis with energy-dispersive spectroscopy, we found that the effects of radiation on bone-plate and bone-screw interfaces is minimal. Although radiation decreased the bone density and the rate of bone repair at the bone-screw interface, this did not appear to affect stability of the plate repair or the viability of bone tissue.