Clinical presentation and risk factors of osteoradionecrosis

Introduction: Osteoradionecrosis (ORN) of the jaws is defined as exposed irradiated bone that fails to heal over a period of 3 months without the evidence of a persisting or recurrent tumor. In the previous decades, numerous factors were associated with the risk of ORN development and severity. Aims: The purposes of this study were to present the data of the patients that were treated for ORN in the Department of Oral and Maxillofacial Surgery in Munich (LMU), to detect factors that contributed to the onset of ORN, to identify risk factors associated with the severity of ORN and finally, to delineate and correlate these factors with the personal, health and treatment characteristics of the patients. Material and Methods: A retrospective study was conducted during the period from January 2003 until December 2012 that included all ORN cases having been treated in the Department of Oral and Maxillofacial Surgery in Munich (LMU). The total sample was categorized in three groups according to stage and several variables were evaluated in an attempt to identify possible correlations between them and the necrosis severity. Results: One hundred and fifty three cases of ORN were documented. Among them, 23 (15.1%) cases were stage I, 31 (20.2%) were stage II and 99 (64.7%) were stage III and all localised in the mandible. There was a predominance of the disease in the posterior region when compared to the anterior region. The majority of cases was addicted to alcohol and tobacco abuse and was suffering from Diabetes Mellitus (DM). All cases were treated with RT and 80.4% of them with concomitant chemotherapy. The initial tumor was predominantly located in the floor of the mouth, the tongue and the pharynx. Αpproximately two thirds of the cases occured either after dental treatment or due to a local pathological condition. Logistic regression analysis identified Diabetes Mellitus (OR: 4.955, 95% Cl: 1.965-12.495), active smoking (OR: 13.542, 95% Cl: 2.085-87.947), excessive alcohol consumption (OR: 5.428, 95% Cl: 1.622-18.171) and dental treatment/ local pathological condition (OR: 0.237, 95% Cl: 0.086-0.655) as significant predictors for stage III necrosis. Tumor size (T) (p<0.001), stage of the tumor (UICC) (p=0.001), concomitant chemotherapy (p<0.001), dental examination and treatment prior to RT (p