title: The influence of dental treatment on the development of osteoradionecrosis after radiotherapy by modern irradiation techniques.
abstract: OBJECTIVE
  The aim of this study was to analyze the influence of dental treatment on the development of osteoradionecrosis (ORN) of the jaw.
  
  
  METHODS
  This study included the data of 776 patients who underwent 3D-CRT or IMRT because of head and neck cancer. Sex, dental status before and after radiotherapy (RT), tumor site, bone surgery during tumor operation, concomitant chemotherapy, and the development of an advanced ORN were documented for each patient. The patients' dentitions before and after RT were classified into four groups with regard to the number and localization of the remaining teeth. Differences between the patients with ORN and patients without ORN with regard to the teeth's condition before and after RT, and with regard to the extent of dental treatment were determined descriptively. Cox proportional hazards regression to study the association between dentition and the development of ORN.
  
  
  RESULTS
  The extent of dental treatment in patients with and without ORN did not differ in a clinically relevant way. The highest risk of developing ORN was observed in patients who had undergone primary bone surgery during the tumor operation (HR = 5.58, 95%CI 2.91-10.7) and patients who had a tumor in the oral cavity (HR = 4.84, 95%CI 1.37-17.11).
  
  
  CONCLUSIONS
  Based on the results of this study, tumor localization and its required treatment are prognostic factors for the development of ORN.
  
  
  CONCLUSIONS
  After implementing a consequent dental treatment scheme, no influence of dentition on the risk of developing ORN could be demonstrated. Patients with a lower risk could prospectively benefit from a more moderate dental treatment scheme.
authors.affiliation: Department of Prosthetic Dentistry, University School of Dental Medicine, Martin-Luther-University Halle-Wittenberg, Große Steinstraße 19, 06108, Halle, Germany. ramona.schweyen@medizin.uni-halle.de.
authors.forename: Ramona
authors.initials: R
authors.lastname: Schweyen
authors.affiliation: Department of Medical Informatics, Biometry and Epidemiology, University Clinic Essen, Hufelandstr. 55, 45122, Essen, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Stang
authors.affiliation: Department of Medical Epidemiology, Biometry and Computer Science, Martin-Luther-University Halle-Wittenberg, Magdeburger Str. 8, 06112, Halle, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wienke
authors.affiliation: Department of Oral and Maxillofacial Plastic Surgery, Martin-Luther-University Halle-Wittenberg, Ernst-Grube-Str. 40, 06120, Halle, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Eckert
authors.affiliation: Department of Radiotherapy, University Clinic, University Leipzig, Stephanstr. 9a, 04103, Leipzig, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kuhnt
authors.affiliation: Department of Prosthetic Dentistry, University School of Dental Medicine, Martin-Luther-University Halle-Wittenberg, Große Steinstraße 19, 06108, Halle, Germany.
authors.forename: Jeremias
authors.initials: J
authors.lastname: Hey
mesh_terms: D059248:Chemoradiotherapy / Q000379:methods; D003729:Dental Care; D005260:Female; D006258:Head and Neck Neoplasms / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010025:Osteoradionecrosis / Q000209:etiology* / Q000517:prevention & control*; D011379:Prognosis; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D012307:Risk Factors
keywords: Bone surgery; Dental status; Osteoradionecrosis; Radiotherapy; Tumor localization