title: Animal model of radiogenic bone damage to study mandibular osteoradionecrosis.
abstract: OBJECTIVE
  The objective of the study was to create an animal model to study mandibular osteoradionecrosis (ORN) using high-dose rate (HDR) brachytherapy.
  
  
  METHODS
  Ten Sprague-Dawley male rats were used in this study. Six rats received a single dose of 30 Gy using an HDR remote afterloading machine via a brachytherapy catheter placed along the left hemimandible. The remaining 4 rats served as controls with catheter placement without radiation (sham). On the day following irradiation or sham, all 3 left mandibular molars were atraumatically extracted. Twenty-eight days after irradiation, mandibles were examined using nondecalcified histology with sequential fluorochrome labeling, decalcified histology, and micro-computed tomography scanning.
  
  
  RESULTS
  Irradiated rats demonstrated exposed bone at the extraction sockets, whereas the control animals had complete mucosalization. Alopecia was also seen in the irradiated group. Both histologic and radiologic analyses of the mandible specimens demonstrated a reduction in bone formation in the radiated mandibles as compared with controls.
  
  
  CONCLUSIONS
  Our HDR brachytherapy model incorporating postradiation dental extractions has successfully demonstrated reproducible radiogenic mandibular bone damage analogous to the clinical ORN. Although clinical criteria continue to be used today in describing ORN, this model can serve as a platform for future studies to define ORN and delineate its pathogenesis.
authors: Division of Head and Neck Surgery, David Geffen School of Medicine at UCLA, University of California-Los Angeles, 10833 LeConte Avenue, Los Angeles, CA 90095, USA.
authors: Marc
authors: M
authors: Cohen
authors: Ichiro
authors: I
authors: Nishimura
authors: Matthew
authors: M
authors: Tamplen
authors: Akishige
authors: A
authors: Hokugo
authors: John
authors: J
authors: Beumer
authors: Michael L
authors: ML
authors: Steinberg
authors: Jeffrey D
authors: JD
authors: Suh
authors: Elliot
authors: E
authors: Abemayor
authors: Vishad
authors: V
authors: Nabili
mesh_terms: D000818:Animals; D008297:Male; D008334:Mandible; D010025:Osteoradionecrosis / Q000175:diagnosis*; D011833:Radiation Injuries, Experimental / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography / Q000379:methods*