# Osteonecrosis of the jaw (medication-related, MRONJ)

Source: https://onco.cc/terms/medication-related-osteonecrosis-of-the-jaw/  
OnCo record `medication-related-osteonecrosis-of-the-jaw` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A rare side effect of bone-strengthening drugs such as zoledronic acid and denosumab, given for cancer in the bones, in which a patch of jawbone is exposed in the mouth and does not heal. A dental check before starting and avoiding tooth extractions during treatment lower the risk.

## Summary

The MASCC/ISOO/ASCO guideline (2019) defines medication-related osteonecrosis of the jaw by three criteria: current or previous treatment with a bone-modifying agent or angiogenic inhibitor; exposed bone, or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region, persisting for longer than 8 weeks; and no history of radiotherapy to the jaws or metastatic disease to the jaws. For people starting a bone-modifying agent, preventive care includes a comprehensive dental assessment, discussion of modifiable risk factors and avoiding elective dentoalveolar surgery during treatment; whether to pause the drug before dental surgery remains uncertain. Staging should be done by an experienced clinician, conservative measures come first, and the guideline stresses collaboration between dentist, dental specialist and oncologist. The radiotherapy exclusion is what separates it from osteoradionecrosis.

## Fields

- Kind: Term
- Last checked: 2026-11-11
- Also known as: Osteonecrosis of the jaw; ONJ; MRONJ; Medication-related osteonecrosis of the jaw; Bisphosphonate-related osteonecrosis of the jaw; BRONJ
- Tags: supportive-care-gaps-2026-11

## Sources

- Yarom et al., Medication-related osteonecrosis of the jaw: MASCC/ISOO/ASCO clinical practice guideline (J Clin Oncol 2019): https://europepmc.org/article/MED/31329513
- NCI PDQ: Oral Complications of Cancer Therapies, health professional version: https://www.cancer.gov/about-cancer/treatment/side-effects/mouth-throat/oral-complications-hp-pdq

## Connected records

- terms: [Osteoradionecrosis of the jaw](https://onco.cc/terms/osteoradionecrosis/)
- technologies: [Bone-modifying agents (bisphosphonates, denosumab)](https://onco.cc/technologies/bone-modifying-agents/)
- drugs: [Denosumab](https://onco.cc/drugs/denosumab/), [Pamidronate](https://onco.cc/drugs/pamidronate/), [Zoledronic acid](https://onco.cc/drugs/zoledronic-acid/)

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