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 Bisphosphonate-related  Osteonecrosis of the Jaw (BON) (BRONJ)
 
 
 
 General Considerations 
  Bisphosphonates are       commonly prescribed for the treatment and prevention of 
      
        Osteoporosis  (e.g. alendronate, risendronate, ibandronate)
    Osteolytic  lesions in metastatic bone tumors (e.g. breast, prostate, multiple myeloma)  (e.g. zoledronate, pamidronate)Hypercalcemia  associated with malignancy Bind and inhibit       osteoclastic activityThere has been an       association described between bisphosphonates,       usually in higher doses in cancer patients, and avascular necrosis,       especially of the mandible
      
        Incidence has  been most strongly correlated with pamidronate (Aredia) and zoledronic acid (Zometa)Many develop after       tooth extraction which may serve as a triggerLatency of 5-36 months       after therapy before osteonecrosis occursMore common with IV       administration of drug than oral Clinical Findings 
  Exposed, non-vital       bonePainSwellingTrismus Imaging Findings 
  Confined to mandible       (majority) and maxillaMixed lytic and       sclerotic lesion of the jawSequestrationPathologic fracturePeriosteal reaction MRI-low T1 and T2       with exposed bone and low T1 and high T2 in unexposed bone Differential Diagnosis 
  Metastatic bone       lesionOsteomyelitis Treatment 
  DifficultDiscontinue bisphosphonate       therapyAvoid dental       extractionsMedical therapy may       include antibiotics used locally and systemicallySurgical curettage       has been usedChemical debridement       with antiseptic irrigationsLong-term antibiotic       treatment may be useful Complications 
  Pathologic fractureOsteomyelitisDraining fistulae 
 
 Bisphosphonate-related Osteonecrosis of the Jaw. Upper photo. Blue arrows point to a large lytic lesion in the right side of the mandible in a patient who had been on high-dose bisphosphonates for multiple myeloma. A tooth (white arrow) had recently been extracted. Lower photo: White arrows point to a lytic lesion in the right side of the mandible with a dense sequestrum within it.For these same photos without the arrows, click here and here
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  Bisphosphonates  and oral cavity avascular bone necrosis. J Clin Oncol 2003;21:4253-4   Bisphosphonate-related  osteonecrosis of the jaw: the Florence experience. A Borgioli,  M Duvina, L Brancato, C Viviani, ML Brandi, and P Tonelli.  Clin Cases Miner Bone Metab. 2007 Jan–Apr; 4(1):  48–52.   eMedicine.  Bisphosphonate-Related Osteonecrosis of the Jaw. RH Blanchaert,  and  CM Harris    
 
 
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