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), formerly called bisphosphonate-related osteonecrosis of the jaw (BPONJ), is a rare and potentially debilitating condition. MRONJ is characterized by nonhealing exposed bone in patients with a history or ongoing use of bisphosphonates
MRONJ may occur spontaneously or after dental extraction or trauma. It occurs preferentially in the mandible (75% of cases) due to the course of the blood supply to the lower jaw. MRONJ may be a refractory osteomyelitis rather than true osteonecrosis, particularly when developing after bisphosphonate use.
Most cases of MRONJ have been in patients with cancer treated with high-dose IV bisphosphonates; very few cases have been reported in patients receiving bisphosphonates for postmenopausal osteoporosis with therapy duration over 4 years. The risk of developing MRONJ is higher in patients who have received antiresorptive medications for metastatic bone disease (< 5% [1]) compared to those receiving such drugs for osteoporosis (< 0.05% [2]).
Oral bisphosphonates are less lipid soluble and result in less accumulation in the bone. The risk of MRONJ in osteoporosis patients taking oral bisphosphonates is extremely low and is comparable to prevalence in the general population (approximately 1 case per 100,000 patient years [3]). Prevalence of MRONJ risk for long-term oral bisphosphonate therapy less than 4 years was 0.1%, and does not appear to exceed 0.21%, even for patients receiving oral bisphosphonate over 4 years (4). Currently, otherwise-appropriate bisphosphonate use should not be discouraged. However, it seems reasonable to do any necessary oral surgery before beginning IV bisphosphonate therapy and to encourage good oral hygiene and regular dental care while patients are taking bisphosphonates (5, 6).
References
1. Saag KG, Petersen J, Brandi ML, et al: Romosozumab or alendronate for fracture prevention in women with osteoporosis. N Engl J Med 377(15):1417-1427, 2017. doi:10.1056/NEJMoa1708322
2. Hallmer F, Andersson G, Götrick B, et al: Prevalence, initiating factor, and treatment outcome of medication-related osteonecrosis of the jaw-a 4-year prospective study. Oral Surg Oral Med Oral Pathol Oral Radiol 126(6):477-485, 2018. doi:10.1016/j.oooo.2018.08.015
3. Masoodi NA: Oral bisphosphonates and the risk for osteonecrosis of the jawBJMP 2(2):11-15, 2022.
4. 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
5. 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
6. 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
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
