Case Report: single low-dose of denosumab as a trigger of MRONJ development in a patient with osteoporosis after bisphosphonate therapy.

Both denosumab (DMB) and bisphosphonates (BPs), antiresorptive drugs (ARDs) used for the treatment of osteoporosis and oncological disorders, are known for their potential to cause medication-related osteonecrosis of the jaws (MRONJ). Besides ARDs, statins were recently associated with MRONJ development, especially in patients taking higher doses of statins for a longer period of time. Here, we report a case of a female patient with osteoporosis using statins and treated with alendronate for 3 years who rapidly developed MRONJ stage III after only a single low dose of DMB. After partial maxillectomy complete healing was observed without any recurrence. We performed a literature review of cases with MRONJ triggered by a single low dose of DMB, with or without previous application of other ARDs. Only six similar cases of patients who developed MRONJ after a single low dose of DMB following previous BP therapy have been reported so far. Besides these, literature reports one patient who developed MRONJ after a single dose of DMB following romosozumab treatment and five cases developing MRONJ after a single dose of DMB even without any previous ARD treatment. We suggest that before DMB therapy is initiated, all factors predisposing to MRONJ development should be considered.