Vertebral fractures after denosumab discontinuation for dental procedures: a consequence of distorted perceptions of risk

In reply: We agree with Goss1 that there should be a conversation between primary physicians and dentists for the best management of patients with osteoporosis. We also agree that osteonecrosis of the jaw is a debilitating disease, as, indeed, are osteoporotic fractures.

Our aims with our case report were twofold. Firstly, we aimed to point out the very different consequences of stopping denosumab to those of stopping bisphosphonates. Secondly, we aimed to highlight the difference in risk between osteonecrosis of the jaw after tooth extraction on denosumab and that of vertebral fractures on delaying denosumab therapy.

The recent update of the position statement from the American Association of Oral and Maxillofacial Surgeons quotes the risk for osteonecrosis of the jaw with denosumab therapy at 0.04–0.3%.2 The risk of vertebral fracture when a denosumab injection is delayed from the last dose is far higher. Our patient’s initial fracture risk was 24% over 10years. Discontinuation of denosumab in the FREEDOM study led to an increase in the rate of vertebral fractures 3.9 times, with more than 60% being multiple vertebral fractures.3 Therefore, a substantial delay in denosumab dosing risks a common adverse event in order to avoid a far less common adverse event.

If there is a window of opportunity for delaying denosumab for dental work, the literature suggests that it is narrow. In a recent case series review, vertebral fractures, often multiple, occurred as early as 7 months after the last denosumab injection.4 This is in accord with Goss’s own suggested timeline of a 4‐week delay.5 The oral and dental section of the Therapeutic Guidelines, however, does not advocate delaying denosumab for extractions.6

Neither our case report nor Goss has mentioned one of the most important pre‐emptive measures to prevent osteonecrosis of the jaw, and that is dental assessment before starting antiresorptive medication. Unfortunately, for many patients with osteoporosis, regular dental care is outside their financial means since the Australian Government does not cover the costs of most dental services in the way it does other health services. That is something for which both physicians and dentists should collaboratively advocate.