title: Impact of bisphosphonate-related osteonecrosis of the jaw on osteoporotic patients after dental extraction: a population-based cohort study.
abstract: OBJECTIVE
  Little is currently known about the risk of developing bisphosphonate-related osteonecrosis of the jaw (BRONJ). This study sought to determine the incidence of BRONJ in osteoporotic patients. We also sought to identify the nature and types of risk factors of osteonecrosis of jaw (ONJ) related to the use of oral bisphosphonates (BPs).
  
  
  METHODS
  Data from the National Health Insurance system of Taiwan. This cohort study included 19,399 adult osteoporosis patients received dental extraction in 2000-2010 (osteoporosis cohort) and 38,669 age and gender matched comparisons selected from dental extraction people without osteoporosis and osteonecrosis history (comparison cohort). All study subjects were followed from the date of their dental extraction (index date) to the development of ONJ and were included in the study up to 2011 or were lost to the study, whichever occurred first. Cox proportional hazard regression was used to estimate the hazard ratio and 95% confidence intervals for the two cohorts.
  
  
  RESULTS
  Patients with osteoporosis had a significantly higher risk to develop ONJ than healthy persons (adjusted HR, 2.05; 95% confidence interval, 1.58-2.65). The risk of ONJ increased with the severity of osteoporosis, no matter whether patient with cancer or not. A cumulative effect of dental extraction frequency may increase the risk of ONJ.
  
  
  CONCLUSIONS
  We concluded that ONJ is caused by a number of factors. Osteoporosis and past dental history play the very important roles, while BPs play the synergistic effect.
authors.affiliation: Department of General Dentistry, Chang Gung Memorial Hospital, Linkou, Taiwan; School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan.
authors.forename: Yi Fang
authors.initials: YF
authors.lastname: Huang
authors.affiliation: School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan; Department of Emergency Medicine, Far Eastern Memorial Hospital, Taipei, Taiwan.
authors.forename: Chung Ta
authors.initials: CT
authors.lastname: Chang
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Chih Hsin
authors.initials: CH
authors.lastname: Muo
authors.affiliation: Department of Orthopedics, China Medical University Hospital, Taichung, Taiwan; Graduate Institute of clinical Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Chun Hao
authors.initials: CH
authors.lastname: Tsai
authors.affiliation: Department of General Dentistry, Chang Gung Memorial Hospital, Linkou, Taiwan.
authors.forename: Yu Fu
authors.initials: YF
authors.lastname: Shen
authors.affiliation: School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan; Department of Dentistry, Taipei Medical University Hospital, Taipei, Taiwan; Department of Dentistry, Lotung PohAi Hospital, Yilan, Taiwan.
authors.forename: Ching Zong
authors.initials: CZ
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000503:physiopathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013624:Taiwan; D014081:Tooth Extraction; D055815:Young Adult