What is the cause of jaw necrosis, also known as osteonecrosis of the jaw (ONJ)?

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From the Guidelines

Jaw necrosis, also known as medication-related osteonecrosis of the jaw (MRONJ), should be diagnosed and managed according to the criteria outlined in the MASCC/ISOO/ASCO clinical practice guideline, which recommends confirming the presence of exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region that has persisted for longer than 8 weeks, in patients with a history of treatment with bone-modifying agents (BMAs) or angiogenic inhibitors, and no history of radiation therapy to the jaws or metastatic disease to the jaws 1. To establish a diagnosis of MRONJ, clinicians should look for the following criteria:

  • Current or previous treatment with a BMA or angiogenic inhibitor
  • Exposed bone or bone that can be probed through an intraoral or extraoral fistula in the maxillofacial region that has persisted for longer than 8 weeks
  • No history of radiation therapy to the jaws or metastatic disease to the jaws 1. Management of MRONJ includes stopping the offending medication when possible, maintaining excellent oral hygiene, and using antimicrobial mouth rinses. The term "medication-related osteonecrosis of the jaw" should be used when referring to bone necrosis associated with pharmacologic therapies in oncology patients, as recommended by the MASCC/ISOO/ASCO clinical practice guideline 1. Prevention is crucial and involves completing all necessary dental work before starting these medications, regular dental check-ups, and avoiding invasive dental procedures while on these drugs. Pain control with acetaminophen or NSAIDs is often necessary, and severe cases may require surgical debridement by specialists, but conservative management is preferred when possible. The condition occurs because these medications inhibit bone remodeling, which is particularly problematic in the jaw due to its high turnover rate and exposure to oral bacteria through the teeth 1. Minor trauma like tooth extraction can trigger the condition in susceptible individuals. It is essential to follow the guidelines and recommendations outlined in the MASCC/ISOO/ASCO clinical practice guideline to ensure proper diagnosis and management of MRONJ 1.

From the Research

Definition and Causes of Jaw Necrosis

  • Jaw necrosis, also known as osteonecrosis of the jaw (ONJ), is a condition associated with the death of bone tissue in the jaw 2.
  • It is often linked to the use of bisphosphonates, a class of drugs used to treat bone diseases such as osteoporosis and cancer [(3,4)].
  • Other risk factors for ONJ include glucocorticoid use, maxillary or mandibular bone surgery, poor oral hygiene, chronic inflammation, diabetes mellitus, and ill-fitting dentures 2.

Diagnosis and Treatment of Jaw Necrosis

  • Diagnosis of ONJ is based on clinical and radiological findings, including exposed necrotic bone in the jaw 3.
  • Treatment of ONJ depends on the stage and severity of the disease, and may include conservative measures such as antibiotic therapy and surgical debridement [(2,3)].
  • Prevention strategies for ONJ include maintaining good oral hygiene, eliminating or stabilizing oral disease prior to initiation of antiresorptive agents, and considering withholding antiresorptive therapy following extensive oral surgery [(2,5)].

Management and Prevention of Bisphosphonate-Related Jaw Necrosis

  • A team approach to management and prevention of bisphosphonate-related jaw necrosis is recommended, involving healthcare professionals and dental practitioners 6.
  • Dental practitioners play a crucial role in early diagnosis and prevention of BRONJ, and should be aware of the risks and mechanisms of the condition [(6,5)].
  • Meticulous oral hygiene and pre-emptive surgical treatment prior to commencement of bisphosphonate therapy are recommended to prevent BRONJ 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Diagnosis and management of osteonecrosis of the jaw: a systematic review and international consensus.

Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research, 2015

Research

Jaw bone necrosis without previous dental extractions associated with the use of bisphosphonates (pamidronate and zoledronate): a four-case report.

Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology, 2005

Research

Bisphosphonate-related osteonecrosis of the jaws: a comprehensive review.

Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology, 2007

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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