AbstractBackgroundIntravenous bisphosphonate therapy has been used for treatment of benign and malignant bone diseases and has been linked to osteonecrosis of the jaws.MethodsRecords of 638 patients treated with intravenous bisphosphonates were reviewed. Drug used, number of infusions, dosing interval, dosage, duration, and occasion of osteonecrosis, diagnosed by history and physical examination, were analyzed.ResultsThe overall incidence of osteonecrosis was 0.94% (6/638). No significant relationship was observed between the incidence of osteonecrosis and demographic parameters, primary tumor, cumulative drug dose, or dosing interval. However, patients who developed osteonecrosis had a significantly greater mean number of infusions (p = .016) and significantly greater mean hours of infusion time (p = .0036).ConclusionsThe findings suggest positive correlation between the development of osteonecrosis and drug exposure as measured by number of infusions and total infusion hours. However, the relatively low incidence of osteonecrosis precluded definition of a direct dose–response relationship. © 2008 Wiley Periodicals, Inc. Head Neck, 2009