Medication-related osteonecrosis of the jaw (MRONJ) describes the bony destruction of the jaw with exposed bone present for greater than eight weeks in the presence of current or previous antiresorptive and/or antiangiogenic medication use, and in the absence of radiation therapy to the head and neck or obvious metastatic disease.
Bisphosphonate-related osteonecrosis of the jaw (BRONJ) was the initially described entity, but MRONJ is now the preferred term as other medications besides bisphosphonates have been implicated as aetiological agents 5,6.
BRONJ is estimated to affect 1 in 10,000 to 100,000 in a patient taking oral bisphosphonates. It more commonly affects females and patients older than 60 years 1 although this likely represents the population receiving bisphosphonates 3.
MRONJ is a painful process and before osteonecrosis becomes clearly evident the patient may present with the following symptoms and signs 2:
- periodontal disease and non-healing mucosal ulcers
- loose teeth
- soft tissue infections
Established BRONJ manifests as necrosis of the jaw with exposed bone.
The definite pathogenesis of MRONJ has not yet been established but is proposed to be related to bone remodeling suppression and antiangiogenic effects of these medications 3. Medications implicated in the formation of MRONJ include 5,6:
- indicated for osteoporosis
- indicated for malignancy
- tyrosine kinase inhibitors, e.g. sunitinib, sorafenib
- bevacizumab (humanised monoclonal antibody)
- recent dental surgery (~65% of patients) 2-3
- IV bisphosphonate use 2-3
- long-term bisphosphonate use 3
- concurrent bone metastases or multiple myeloma 1-2
- dental or periodontal disease 3
Plain radiograph and CT
Features are non-specific and include 1:
- poorly defined lucent, mixed or sclerotic lesion
- periosteal proliferation
- destruction of adjacent structures
Plain films and OPGs may not demonstrate early disease 1,3.
- radiation necrosis of the jaw (mandibular osteoradionecrosis): virtually indistinguishable clinically and radiologically 2
- 1. Haworth AE, Webb J. Skeletal complications of bisphosphonate use: what the radiologist should know. Br J Radiol. 2012;85 (1018): 1333-42. doi:10.1259/bjr/99102700 - Free text at pubmed - Pubmed citation
- 2. Ficarra G, Beninati F. Bisphosphonate-related osteonecrosis of the jaws: an update on clinical, pathological and management aspects. Head Neck Pathol. 2007;1 (2): 132-40. doi:10.1007/s12105-007-0033-2 - Free text at pubmed - Pubmed citation
- 3. Ruggiero SL. Guidelines for the diagnosis of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Clin Cases Miner Bone Metab. 2012;4 (1): 37-42. Free text at pubmed - Pubmed citation
- 4. Vescovi P, Nammour S. Bisphosphonate-Related Osteonecrosis of the Jaw (BRONJ) therapy. A critical review. Minerva Stomatol. 2010;59 (4): 181-203, 204-13. Pubmed citation
- 5. Katsarelis H, Shah NP, Dhariwal DK et-al. Infection and medication-related osteonecrosis of the jaw. J. Dent. Res. 2015;94 (4): 534-9. doi:10.1177/0022034515572021 - Pubmed citation
- 6. Ruggiero SL, Dodson TB, Fantasia J et-al. American Association of Oral and Maxillofacial Surgeons position paper on medication-related osteonecrosis of the jaw-2014 update. J. Oral Maxillofac. Surg. 2014;72 (10): 1938-56. doi:10.1016/j.joms.2014.04.031 - Pubmed citation