- The terms MRONJ (Medication related osteonecrosis of the jaw) and ARONJ (Antiresorptive drug related osteonecrosis of the jaw) presently replace the term BRONJ.
- MRONJ is similar to osteonecrosis, and is usually identified by the appearance of exposed bone in the oral cavity.
- MRONJ is difficult to treat. If patient is diagnosed with MRONJ, advice and cooperation with entire involved dental and medical rehabilitation team is critical.
- Bisphosphonates (BP) may predispose to ‘bisphosphonate-related osteonecrosis of the jaw’ (BRONJ).
A critical side effect in the oro-maxillo-facial region observed in patients undergoing administration over a long period of time and especially intravenously, bisphosphonate therapy may predispose to ‘bisphosphonate-related osteonecrosis of the jaw’ (BRONJ), or 'antiresorptive drug related osteonecrosis of the jaw' (ARONJ). By definition this is an area of exposed bone in the jaw persisting for more than 8 weeks with no history of radiation therapy while having undergone a bisphosphonate or other anti-resorptive drug therapy.
Incidence of ARONJ/MRONJ as a result of bisphosphonate or other anti-resorpive drug treatment of osteoporosis and Paget's disease is between 0.01% - 0.04%. Consequent to bisphosphonate administration for the treatment of bone cancers and metastases, the incidence of BRONJ is 0.8% - 12%.
Medication-related osteonecrosis of the jaw is similar to osteoradionecrosis and very difficult to treat. The affected bone seems to have impaired healing capacity (reduced turnover) and reduced angiogenesis. The result is a reduced capability to deal with infections and trauma (surgery, tooth extractions).
Figure 1: MRONJ - empty lacunae are seen in the center of the bone while towards the surface some lacunae display their osteocytes.
© 2013 Sharma et al.; Vascular Cell 2013 Jan 14;5(1):1. doi: 10.1186/2045-824X-5-1.
MRONJ treatment considerations
If patient is diagnosed with MRONJ, surgery and tooth extraction should be avoided. Hygiene measures should be reassessed and reinforced. This conditions requires a team approach and regular communication between GP, internist, dentist and oral and maxillofacial surgeon.
Detailed and extensive clinical practice guidelines for management of the bisphosphonate patient are available. Some fundamental treatment steps to be used are:
- Daily irrigation and antimicrobial rinse
- Antibiotics to control infection
- Surgical treatment to remove the necrotic bone may be advisable in more advanced cases
- In some patients a removable appliance to cover and protect the exposed bone is necessary
- Protective stent damages the surrounding soft tissues or makes normal function difficult
- If dentures are worn, minimize irritation of the soft-tissues, particularly for patients who are receiving IV bisphosphonate therapy. Dentures should be removed and thoroughly cleaned at night.
(Content © Copyright AAOMS 2008-2013)
Figure 2: Clinical image of BRONJ.
Courtesy of Dr. Sreenivas Koka, San Diego