Medication-related osteonecrosis of the jaw has no unanimously accepted definition or etiology but is generally held to be an oral lesion involving bare mandibular or maxillary bone present for ≥ 8 weeks related to medications. It may cause pain or may be asymptomatic. Diagnosis is by the presence of exposed bone for at least 8 weeks. Treatment is limited debridement, antibiotics, and oral rinses.
Medication-related osteonecrosis of the jaw (MRONJ) is a rare and potentially debilitating dental emergency. MRONJ is characterized by nonhealing exposed bone in patients with a history or ongoing use of bisphosphonates (particularly administered via high-dose IV) and other antiresorptive agents (eg, denosumab), or an antiangiogenic agent and no history of radiation exposure to the head and neck region. Very rarely, osteonecrosis of the jaw (ONJ) with the same clinical manifestations as MRONJ occurs in patients who have not been treated with bisphosphonates or antiresorptive or antiangiogenic agents.
MRONJ may occur spontaneously or after dental extraction or trauma. It occurs preferentially in the mandible (in approximately 75% of cases) due to the reduced blood supply to the mandible compared with that to the maxilla (1). MRONJ may be a refractory osteomyelitis rather than true osteonecrosis, particularly when it develops after bisphosphonate use.
Most cases of MRONJ have been in patients with cancer treated with high-dose IV bisphosphonates. Although less common, cases have also been reported in patients receiving bisphosphonates for postmenopausal osteoporosis (2, 3).
The overall risk of MRONJ in patients with osteoporosis taking oral bisphosphonates is extremely low (approximately < 0.02 percent) (2); thus, appropriate bisphosphonate use should not be discouraged. However, performing any necessary oral surgery prior to initiating bisphosphonate therapy should be considered. Patients should be instructed to perform good oral hygiene and receive regular dental care while taking bisphosphonates (4, 5).
References
1. Saad F, Brown JE, Van Poznak C, et al. Incidence, risk factors, and outcomes of osteonecrosis of the jaw: integrated analysis from three blinded active-controlled phase III trials in cancer patients with bone metastases. Ann Oncol. 2012;23(5):1341-1347. doi:10.1093/annonc/mdr435
2. Masoodi NA. Oral bisphosphonates and the risk for osteonecrosis of the jaw. BJMP. 2(2):11-15, 2022.
3. Ruggiero SL, Dodson TB, Aghaloo T, et al. American Association of Oral and Maxillofacial Surgeons' Position Paper on Medication-Related Osteonecrosis of the Jaws-2022 Update. J Oral Maxillofac Surg. 80(5):920-943, 2022. doi:10.1016/j.joms.2022.02.008
4. Hellstein JW, Adler RA, Edwards B, et al. Managing the care of patients receiving antiresorptive therapy for prevention and treatment of osteoporosis: Executive summary of recommendations from the American Dental Association Council on Scientific Affairs. J Am Dent Assoc. 142(11):1243−1251, 2011. doi: 10.14219/jada.archive.2011.0108
5. Khan A, Morrison A, Cheung A, et al. Osteonecrosis of the jaw (ONJ): Diagnosis and management in 2015. Osteoporos Int. 27(3):853–859, 2016. doi: 10.1007/s00198-015-3335-3
Symptoms and Signs of MRONJ
MRONJ may be asymptomatic for long periods. Symptoms tend to develop along with signs, although pain may precede signs. In later stages, MRONJ usually manifests with pain and purulent discharge from exposed bone in the mandible or, much less often, the maxilla. The teeth and gingiva may be involved. Intraoral or extraoral fistulas may develop.
Diagnosis of MRONJ
Clinical evaluation
MRONJ is diagnosed when exposed, necrotic bone is present in the maxilla or mandible for at least 8 weeks.
Treatment of MRONJ
Limited debridement, antibiotics, and oral rinses
Once established, MRONJ is challenging to treat and should be managed by an oral surgeon with experience treating MRONJ. Treatment of MRONJ typically involves limited debridement, antibiotics, and antibacterial oral rinses (eg, chlorhexidine [1]).
Surgical resection of the affected area may worsen the condition and should not be the initial treatment.
Treatment reference
1. Hellstein JW, Adler RA, Edwards B, et al. Managing the care of patients receiving antiresorptive therapy for prevention and treatment of osteoporosis: Executive summary of recommendations from the American Dental Association Council on Scientific Affairs. J Am Dent Assoc 142(11):1243−1251, 2011. doi: 10.14219/jada.archive.2011.0108
