title: Osteonecrosis of the jaw in Sweden associated with the oral use of bisphosphonate.
abstract: OBJECTIVE
  To estimate the incidence of bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) associated with the use of oral BPs and osteonecrosis of the jaw (ONJ) not associated with current or previous medication with a BP or radiotherapy to the head and neck region (background ONJ) in Sweden.
  
  
  METHODS
  A survey was sent to all oral and maxillofacial surgery clinics and hospital dental clinics in Sweden. They were requested to report all new cases of BRONJ and background ONJ during 2007 and 2008.
  
  
  RESULTS
  The response rate was 61%. The oral BRONJ incidence for patients aged 45 years or older was 67 cases/100,000 patient-years of BP medication in 2007 (1 case/1,500 patient-years). In 2008, 69 cases/100,000 patient-years (1 case/1,445 patient-years) were reported. The mean age at the development of oral BRONJ was 76.5 ± 10.8 years (median age 79, range 49 to 96) for 2007 and 79.8 ± 7.6 years (median 79, range 67 to 94) for 2008. Women were primarily affected (22 of 26 in 2007 and 25 of 29 in 2008). The incidence of background ONJ was low: 0.14 and 0.09/100,000 person-years for those aged 45 years or older in 2007 and 2008, respectively (3 cases in 2007 and 2 in 2008).
  
  
  CONCLUSIONS
  The BRONJ incidence has been estimated to be more than 100-fold greater than the incidence of background ONJ. However, an average Swedish dental practice (1,234 patients) will only encounter 1 patient with new oral BRONJ every 62 nd year.
authors.affiliation: Consultant, Department of Oral and Maxillofacial Surgery, Karolinska University Hospital, Stockholm, Sweden. Electronic address: mattias.ulmner@karolinska.se.
authors.forename: Mattias
authors.initials: M
authors.lastname: Ulmner
authors.affiliation: Consultant, Department of Oral and Maxillofacial Surgery, Karolinska University Hospital, Stockholm, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Jarnbring
authors.affiliation: Associate Professor, Department of Clinical Research and Education, Södersjukhuset, Karolinska Institute, Stockholm, Sweden.
authors.forename: Ove
authors.initials: O
authors.lastname: Törring
mesh_terms: D000284:Administration, Oral; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000008:administration & dosage / Q000009:adverse effects; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000453:epidemiology*; D050071:Bone Density Conservation Agents / Q000008:administration & dosage / Q000009:adverse effects; D003430:Cross-Sectional Studies; D004164:Diphosphonates / Q000008:administration & dosage / Q000009:adverse effects; D005260:Female; D006801:Humans; D015994:Incidence; D007571:Jaw Diseases / Q000453:epidemiology; D008297:Male; D008336:Mandibular Diseases / Q000453:epidemiology; D008439:Maxillary Diseases / Q000453:epidemiology; D008875:Middle Aged; D010020:Osteonecrosis / Q000453:epidemiology; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology
chemical_list: D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D019386:Alendronate