title: Risk factors for and the role of dental extractions in osteoradionecrosis of the jaws: A national-based cohort study.
abstract: The purpose of this study was to investigate the risk factors, especially the use of certain drugs and the dental procedures, for osteoradionecrosis of the jaw (ORNJ) in patients with head and neck cancer undergoing irradiation as their primary treatment.
  
  
  
  The cohort was composed of 23,527 patients with head and neck cancer. Cox proportional hazard models were used for risk factors analysis.
  
  
  
  The overall incidence of ORNJ is 3.93 per 100 person-years. Buccal cancer carried the highest ORNJ risk. The use of steroids had a protective effect. Preradiotherapy extraction posed no excess risk, whereas postradiotherapy extraction was associated with gradually increased risk of ORNJ over time that peaked at 4 to 5 years.
  
  
  
  ORNJ warrants life-long attention for head and neck cancer survivors. The present study strongly confirms the role of preirradiation dental extractions. Meanwhile, efforts should be made to prevent posttreatment extractions, especially in the first posttreatment 4 years. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1313-1321, 2017.
authors.affiliation: Cancer Center, Taipei Veterans General Hospital, Taipei, Taiwan.|Department of Radiation Oncology, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Ti-Hao
authors.identifier: 0000-0002-2105-0133
authors.initials: TH
authors.lastname: Wang
authors.affiliation: Division of Hematology and Oncology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Chia-Jen
authors.initials: CJ
authors.lastname: Liu
authors.affiliation: School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.|Institute of Clinical Medicine and Cardiovascular Research Center, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Tze-Fan
authors.initials: TF
authors.lastname: Chao
authors.affiliation: Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.|Department of Family Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
authors.forename: Tzeng-Ji
authors.initials: TJ
authors.lastname: Chen
authors.affiliation: Cancer Center, Taipei Veterans General Hospital, Taipei, Taiwan.|Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.|School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yu-Wen
authors.initials: YW
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D016208:Databases, Factual; D018572:Disease-Free Survival; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D007568:Jaw / Q000469:parasitology; D008297:Male; D008875:Middle Aged; D056948:Orthognathic Surgical Procedures; D010025:Osteoradionecrosis / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D016016:Proportional Hazards Models; D011878:Radiotherapy / Q000009:adverse effects* / Q000379:methods; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D013624:Taiwan; D014081:Tooth Extraction / Q000379:methods / Q000639:trends*; D016896:Treatment Outcome
keywords: dental extraction; head and neck cancer; osteoradionecrosis of the jaw; radiotherapy; steroid