title: Osteo-radio-necrosis (ORN) and bisphosphonate-related osteonecrosis of the jaws (BRONJ): the histopathological differences under the clinical similarities.
abstract: OBJECTIVE
  Both osteoradionecrosis (ORN) and bisphosphonate associated osteonecrosis of the jaws (BRONJ) present clinically as regions of exposed necrotic bone. The study aimed to demonstrate the histopathological differences behind the observed clinical similarities.
  
  
  METHODS
  Ten ORN specimens and ten BRONJ specimens were used, as well as ten samples of normal mandibular bone as control. Two bone-specific stainings were used, i.e. Sirius Red for the study of the relative presence of collagen types I and III and toluidine blue for the study the osteon density.
  
  
  RESULTS
  The Red Green Blue (RGB)-analysis of the specimens stained with Sirius Red identified significant differences between the chromatic patterns observed in bone preparations of patients suffering from ORN when compared to both BRONJ and control samples. Moreover, the osteon density of the BRONJ samples was significantly lower when compared to ORN and normal bone samples.
  
  
  CONCLUSIONS
  The demonstrated differences in the bone architecture and in the bone collagen content between the two pathological conditions most likely reflect underlying pathophysiological differences.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital of Erlangen Germany.
authors.forename: Konstantinos T
authors.initials: KT
authors.lastname: Mitsimponas
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital of Erlangen Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Moebius
authors.affiliation: Institute for Nephropathology, University Hospital of Erlangen Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Amann
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital of Erlangen Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Stockmann
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital of Erlangen Germany.
authors.forename: Karl-Andreas
authors.initials: KA
authors.lastname: Schlegel
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital of Erlangen Germany.
authors.forename: Friedrich-Wilhelm
authors.initials: FW
authors.lastname: Neukam
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital of Erlangen Germany.
authors.forename: Falk
authors.initials: F
authors.lastname: Wehrhan
mesh_terms: D001391:Azo Compounds; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000378:metabolism / Q000473:pathology*; D016022:Case-Control Studies; D024042:Collagen Type I; D024043:Collagen Type II; D004396:Coloring Agents; D003937:Diagnosis, Differential; D005260:Female; D006253:Haversian System / Q000737:chemistry / Q000473:pathology; D006801:Humans; D008297:Male; D008334:Mandible / Q000737:chemistry / Q000473:pathology*; D008859:Microscopy, Polarization; D008875:Middle Aged; D010025:Osteoradionecrosis / Q000378:metabolism / Q000473:pathology*; D011237:Predictive Value of Tests; D013194:Staining and Labeling / Q000379:methods; D014048:Tolonium Chloride
chemical_list: D001391:Azo Compounds; D024042:Collagen Type I; D024043:Collagen Type II; D004396:Coloring Agents; D014048:Tolonium Chloride
keywords: Osteoradionecrosis; Sirius red; bisphosphonate-associated osteonecrosis; bone structure; collagen; toluidine blue