Time since last intravenous bisphosphonate and risk of osteonecrosis of the jaw in osteoporotic patients.

Medication-related osteonecrosis of the jaw is a rare but serious condition in which the jawbone fails to heal and becomes necrotic, typically after dental surgery in patients treated with bisphosphonates. However, clear evidence guiding how long bisphosphonate treatment should be paused before dental surgery remains limited. Here we show that a longer time since the last dose of intravenous bisphosphonate is associated with a reduced risk of jawbone necrosis. Using a nationwide retrospective cohort of 152,299 older adults diagnosed with osteoporosis, we analyze the relationship between the duration of bisphosphonate discontinuation prior to dental extraction and the occurrence of osteonecrosis of the jaw. We find that the risk is substantially lower when treatment is paused for more than 90 days, and lowest when the pause exceeds one year. The risk reduction appears more consistent with ibandronate, whereas with zoledronate, only pauses longer than one year show a meaningful association. These findings underscore the potential value of personalized prevention strategies based on bisphosphonate type.