PURPOSE: The devastation radiation therapy (XRT) causes to endogenous tissue in @entity1 with @entity135 can be a prohibitive obstacle in reconstruction of the mandible, demanding a better understanding of XRT-induced damage and options for reconstruction. This study investigated the cellular damage caused by radiation in an isogenic @entity19 model of mandibular distraction osteogenesis (DO). The authors posited that radiation would result in fewer osteocytes, with increased empty lacunae and immature osteoid. MATERIALS AND METHODS: Twenty Lewis @entity35 were randomly assigned to a DO group (n  = 10) or a  XRT/DO group (n  = 10). These groups underwent an osteotomy and mandibular DO across a 5.1-mm gap. XRT was administered to the XRT/DO group at a fractionated @entity1 equivalent dose of 35  Gy before surgery. Animals were sacrificed on postoperative day 40 and mandibles were harvested and sectioned for histologic analysis. RESULTS: Bone that underwent radiation showed a significantly decreased osteocyte count and complementary increase in empty lacunae compared with non-XRT bone (P  = .019 and P  = .000). In addition, XRT bone exhibited increased immature osteoid and decreased mature woven bone compared with nonradiated bone (P  = .001 and P  = .003, respectively). Furthermore, analysis of the ratio of immature osteoid to woven bone volume exhibited a significant increase in the XRT bone, further showing the devastating damage from XRT (P  = .001). CONCLUSION: These results clearly show the cellular diminution that occurs as a result of radiation. This foundational study provides the groundwork on which to investigate cellular therapies in an immuno-privileged model of mandibular DO.

A Histomorphometric Analysis of Radiation Damage in an Isogenic XXXX Model of Distraction Osteogenesis.

@entity1 :: ('9606', 'Species') :: ['patients', 'human'] @entity135 :: ('MESH:D006258', 'Disease') :: ['head and neck cancer'] @entity19 :: ('10090', 'Species') :: ['murine'] @entity35 :: ('10116', 'Species') :: ['rats']
@entity19 :: (10090,Species) :: ['Murine']
