Definition and Overview
- MRONJ is the progressive death of the jawbone in individuals exposed to certain medications.
- It can occur after oral and maxillofacial surgery, periodontal surgery, or endodontic therapy.
- Medications that increase the risk of MRONJ include anti-resorptive drugs and anti-angiogenic drugs.
- Previously known as bisphosphonate-related osteonecrosis of the jaw (BRONJ).
- No known prevention for bisphosphonate-associated osteonecrosis of the jaw.
Signs, Symptoms, and Cause
- MRONJ can cause ulcers or areas of necrotic bone for weeks, months, or even years following a tooth extraction.
- Mild pain may be experienced due to inflammation of surrounding tissues.
- Other signs and symptoms include jaw pain, loose teeth, mucosal swelling, erythema, suppuration, soft tissue ulceration, trismus, non-healing extraction sockets, paraesthesia or numbness in the jaw, bad breath, and exposed necrotic jaw bone.
- Symptoms persist for more than 8 weeks.
- Patients may be asymptomatic.
- MRONJ can be associated with the use of intravenous and oral bisphosphonates.
- Scientists believe there is a correlation between jaw necrosis and exposure to bisphosphonates.
- Bone injury in patients using bisphosphonates may contribute to the development of MRONJ.
- Other medications and factors may also play a role in causing MRONJ.
- The exact cause of MRONJ is still unclear.
Risk Factors and Research Findings
- MRONJ is more commonly associated with intravenous administration of bisphosphonates.
- Dental treatment, duration of bisphosphonate drug therapy, and other concurrent medications increase the risk of MRONJ.
- Dental implants and previous treatment with anti-resorptive/anti-angiogenic drugs are also risk factors.
- Patients being treated for cancer have a higher risk, while those being treated for osteoporosis/non-malignant bone diseases have a lower risk.
- Drug holidays or stopping bisphosphonate use do not necessarily reduce the risk of MRONJ.
- The risk of MRONJ after dental extraction is higher in patients treated with antiresorptive drugs for oncological reasons compared to those treated for osteoporosis.
- Adjusted extraction protocols can decrease the development of MRONJ.
- Concomitant medications and pre-existing osteomyelitis are potential risk indicators for MRONJ.
- The risk of MRONJ is influenced by various factors and circumstances.
- Further research is needed to better understand and prevent MRONJ.
Medications Associated with MRONJ
- Anti-resorptive drugs inhibit osteoclast differentiation and function.
- Two main types of anti-resorptive drugs are bisphosphonates and denosumab.
- Bisphosphonates are administered orally or intravenously and reduce bone resorption.
- Denosumab is a monoclonal antibody administered subcutaneously that inhibits osteoclast differentiation and activation.
- Anti-angiogenic drugs interfere with blood vessel formation and are primarily used to treat cancer.
Management and Treatment Options
- Treatment involves antimicrobial mouthwashes and oral antibiotics to fight infection.
- Local resection of the necrotic bone lesion is often performed.
- Severity of osteonecrosis determines the treatment received.
- Conservative management includes antiseptic mouthwashes, analgesics, and teriparatide.
- Non-surgical management involves antimicrobial mouthwashes, systemic antibiotics, antifungal medication, and analgesics.
- Surgical intervention may be necessary for symptomatic exposed bone, fistula formation, and specific conditions.
- Other treatment options include hyperbaric oxygen therapy and ultrasonic therapy.
- Antibiotics are used to treat cases involving infections, with penicillin being the first-line choice.
Medication-related osteonecrosis of the jaw (MON, MRONJ) is progressive death of the jawbone in a person exposed to a medication known to increase the risk of disease, in the absence of a previous radiation treatment. It may lead to surgical complication in the form of impaired wound healing following oral and maxillofacial surgery, periodontal surgery, or endodontic therapy.
| Medication-related osteonecrosis of the jaw | |
|---|---|
| Other names | MON of the jaw, Medication-related osteonecrosis of the jaw (MRONJ), Medication-induced osteonecrosis of the jaw (MIONJ), Bisphosphonate-related osteonecrosis of the jaw (BRONJ) (formerly) |
 | |
| Specialty | Oral and maxillofacial surgery |
| Symptoms | Exposed bone after extraction, pain |
| Complications | Osteomyelitis of the jaw |
| Usual onset | After dental extractions |
| Duration | Variable |
| Types | Stage 1-Stage 3 |
| Causes | Medications related to cancer therapy, and osteoporosis in combination with dental surgery |
| Risk factors | Duration of anti-resorptive or anti-angiogenic drugs, intravenous vs by-mouth |
| Diagnostic method | Exposed bone >8 weeks |
| Differential diagnosis | Osteomyelitis, Osteoradionecrosis |
| Prevention | No definitive. Drug holiday for some patients. |
| Treatment | antibacterial rinses, antibiotics, removal exposed bone |
| Prognosis | good |
| Frequency | 0.2% for those on biphosphonate type drugs >4 years |
Particular medications can result in MRONJ, a serious but uncommon side effect in certain individuals. Such medications are frequently used to treat diseases that cause bone resorption such as osteoporosis, or to treat cancer. The main groups of drugs involved are anti-resorptive drugs, and anti-angiogenic drugs.
This condition was previously known as bisphosphonate-related osteonecrosis of the jaw (BON or BRONJ) because osteonecrosis of the jaw correlating with bisphosphonate treatment was frequently encountered, with its first incident occurring in 2003. Osteonecrotic complications associated with denosumab, another antiresorptive drug from a different drug category, were soon determined to be related to this condition. Newer medications such as anti-angiogenic drugs have been potentially implicated causing a very similar condition and consensus shifted to refer to the related conditions as MRONJ; however, this has not been definitively demonstrated.
There is no known prevention for bisphosphonate-associated osteonecrosis of the jaw. Avoiding the use of bisphosphonates is not a viable preventive strategy on a general-population basis because the medications are beneficial in the treatment and prevention of osteoporosis (including prevention of bony fractures) and treatment of bone cancers. Current recommendations are for a 2-month drug holiday prior to dental surgery for those who are at risk (intravenous drug therapy, greater than 4 years of by-mouth drug therapy, other factors that increase risk such as steroid therapy).
It usually develops after dental treatments involving exposure of bone or trauma, but may arise spontaneously. Patients who develop MRONJ may experience prolonged healing, pain, swelling, infection and exposed bone after dental procedures, though some patients may have no signs/symptoms.
