CONDOR Study of Osteonecrosis of the Jaws

Osteonecrosis of the jaws (ONJ) is a potentially morbid and costly oral condition. In the recent past more than 200 cases of ONJ have been described in patients treated with bisphosphonates (BPs) for osseous cancer lesions or osteoporosis. The number of BP prescriptions has been steadily increasing, creating concerns about this potential side effect. The causes and risk factors for ONJ are not known. In this study we investigated these issues making use of the research infrastructure from the three dental practice-based research networks (PBRNs) funded by NIDCR.

The specific aims of this study were to test the hypotheses that: (1) BP treatment is a risk factor for ONJ; and (2) dental diseases, particularly periodontal disease and invasive dental procedures such as dental extractions are true risk factors for ONJ, or whether these procedures are a consequence of the necrotic disease process. This study quantified the impact that BP exposure had on the risk of developing ONJ, relative to comparable control patients, using a case-control study design. The risk factors studied included BPs, dental risk factors, and other factors, such as radiation and steroid therapy. All the patients with ONJ identified from the PBRNs were recruited for the study. Cases were identified by a dentist in the PBRN and were diagnosed by the dentist or a specialist as having ONJ with an onset between January 2005 and January 2007. Each case had three controls from the practice that identified the case. The dentist summarized the relevant dental treatment history and provided a dental disease diagnosis history from January 2000 until diagnosis of ONJ for cases, and until recruitment for controls. A professional centralized interviewer within each PBRN administered the same standardized questionnaire to cases and controls over the telephone.

Relevance to public health: This study was a unique and timely opportunity to investigate risk factors for ONJ, results from which may have a substantial impact on dental health and oral-related quality of life in an increasing number of patients.