Influence of bisphosphonates on clinical features of osteoradionecrosis of the maxilla and mandible.

BACKGROUND AND PURPOSE: Osteoradionecrosis (ORN) is one of the most severe adverse effects of radiotherapy (RT) to the head and neck region. Medication-induced osteonecrosis of the jaw has been reported among patients using bisphosphonates. However, the impact of RT on osteonecrosis in patients using bisphosphonates has not yet been described. Therefore, the aim of this study was to compare ORN characteristics between patients who use and do not use bisphosphonates.

MATERIALS AND METHODS: This retrospective study evaluated 96 patients with ORN of the jaw. Patients were divided into group I (patients who did not receive bisphosphonates, n = 83) and group II (patients who did receive bisphosphonates, n = 13). Clinical data were obtained from medical charts.

RESULTS: Osteoradionecrosis more often involved the mandibular jaw than the maxillary jaw for both patient groups. However, maxillary involvement was more common among patients who received bisphosphonates than those who did not (p = 0.014). There was also a trend toward earlier development of ORN in the group that received bisphosphonates (p = 0.21).

CONCLUSIONS: Bisphosphonate use appears to contribute to earlier development of ORN. Long-term prospective studies are needed to understand the pathogenesis of ORN in patients treated with combined radiation and bisphosphonate therapy.