Bisphosphonate-Related Osteonecrosis of the Jaws: A Case-Control Study of Risk Factors in Breast Cancer Patients

Osteonecrosis of the jaws (ONJ) was initially described in 2001 in patients receiving intravenous bisphosphonate (BP) treatment. The objective of the present study was to determine whether routine dental procedures can be considered as possible risk factors for the development of ONJ in breast cancer patients receiving BP.Twenty breast cancer patients who developed ONJ receiving BP treatment were included in group A, whereas group B consisted of 40 matched controls (breast cancer patients who did not progress to ONJ receiving BP treatment). Routine dental care, smoking habits, history of tooth extraction, use of dentures, and root canal therapy were recorded.Our results indicate that history of tooth extraction during zoledronic acid treatment (adjusted odds ratio [OR] = 16.4; 95% CI, 3.4 to 79.6) and the use of dentures (adjusted OR = 4.9; 95% CI, 1.2 to 20.1) increase the risk of developing ONJ.The outcome of the present study suggests early referral by oncologists for dental evaluation for every patient to be treated with BP. These results raise the current American Society of Clinical Oncology Level of Evidence linking certain dental procedures with ONJ from V to III. Further studies are needed to assess other possible risk factors and also to highlight the etiopathogenesis mechanism of ONJ.