title: Bisphosphonates and osteonecrosis of the jaw: cause and effect or a post hoc fallacy?
abstract: BACKGROUND
  An increasing amount of reports are being published suggesting a relationship between the use of bisphosphonates (BPs) and the development of osteonecrosis of the jaw (ONJ). We reviewed the currently available evidence and explore the potential mechanisms of action based on the known effects of the concerned BP.
  
  
  METHODS
  The MEDLine, Current Contents and Science Citation Index Expanded databases were queried and the results augmented by analyzing cited references and recent congress proceedings.
  
  
  RESULTS
  22 papers were included detailing 225 patients, all based on retrospective chart review without control groups. The prevalence of ONJ was estimated at 1.5%. The involved BPs were pamidronate, zoledronic acid, alendronate and risedronate, all potent nitrogen-containing agents. The most common symptom was pain (81.7%), although 12.2% of cases were asymptomatic. In 69.3% of patients ONJ was preceded by a dental extraction. At the time of diagnosis, 74.5% of patients were receiving chemotherapy and in 38.2% of cases corticosteroids were administered. Although various conservative and surgical treatment modalities were reported, residual sites of ONJ persisted in 72.5% of cases.
  
  
  CONCLUSIONS
  Although not enough evidence is available to prove a causal link, it seems that under specific circumstances local defenses can become overwhelmed resulting in ONJ.
authors.affiliation: Department of Medical Oncology, Antwerp University Hospital, Belgium. tim.van.den.wyngaert@skynet.be
authors.forename: T
authors.initials: T
authors.lastname: Van den Wyngaert
authors.forename: M T
authors.initials: MT
authors.lastname: Huizing
authors.forename: J B
authors.initials: JB
authors.lastname: Vermorken
mesh_terms: D050071:Bone Density Conservation Agents / Q000009:adverse effects* / Q000627:therapeutic use; D004164:Diphosphonates / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D007571:Jaw Diseases / Q000139:chemically induced*; D010020:Osteonecrosis / Q000139:chemically induced*
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates