What is ONJ (Osteonecrosis of the Jaw)? How is ONJ treated?

What is ONJ or osteonecrosis of the jaw? So very often my patients ask me, what is ONJ and what is the risk of ONJ? What can I do to prevent ONJ and how do I treat this? So ONJ stands for osteonecrosis of the jaw. How do I diagnose this? It's exposed bone in the cavity, on the mouse cavity of our patients. It's not painful and very often patients come to me and say, doctor, can you check my mouse? I have exposed bone. What is this? Or they come and say, my dentist sent me to you. I think I have ONJ. So ONJ is something we don't like. And fortunately, at most, 3% of our patients develop ONJ. We learned that ONJ occurs with an increased use of bisphosphonates. So 10 years ago, at the time, we gave everybody bisphosphonates, aridia or zomera, monthly indefinitely. Up to 10% of the patients developed the ONJ. Right now, it's less and less. And we know using bisphosphonates judiciously, so that means limited for at most two years, significantly decreases the risk of ONJ. This is one part. But the other part, what can the patient do to reduce ONJ? So we know that the austenic process of the jaw is associated not only with the frequency and with the number of treatments you receive as bisphosphonates, it's also associated with dental hygiene. That means when you have an infected tooth, your risk to develop ONJ is much higher. So what we recommend our patients before they start bisphosphonates, go and see your dentist and make sure that your dentist did all major dental work. What does that mean? That means, for instance, root canals or tooth extractions. It's also important when you're on bisphosphonates that you let your doctor know that currently you received zomera or aridia. The doctor might take certain precautions before he extracts a tooth, for instance, give you antibiotics. So it's important that the dentist knows about that. When you're on bisphosphonates, it's important that not only you let your doctor know that you're on bisphosphonates, it's also important that you have regular dental checkups. Your doctor is allowed to do everything that's just on the surface of your tooth, for instance, cleaning of your tooth or filling cavities. That there's no increased risk of ONJ associated with those, I would say, minor procedures. Again, make sure you go to the dentist, make sure that you have your regular follow up, that you have your dental clinic, make sure you have healthy gums. But in case you feel anything that's abnormal in your mouth, maybe sharp edges, you see exposed bone, go to your doctor, go to your oncologist and go to your dentist and discuss it. What would the hematologist or oncologist do? He would stop the bisphosphonates, that's number one, but we would also treat you with antibiotics with the hope that the ONJ can hear. Unfortunately, ONJ is something that can be very persistent. And many, many patients have ONJ over several years. ONJ stands for osteonecrosis of the jaw, which is a condition whereby the bone in the jaw does not heal. I think in order to understand ONJ, we need to understand normal bone physiology. So on the surface of our bone, there are always microcracks that occur, and we have these cells called osteoclasts, which come in and scoop out a little bit of bone, and then cells which are called osteoblasts, which come in and basically fill in those holes and basically in that way remodel the bone. Our skeleton does this all the time, so that on average we replace our entire skeletons about every eight to ten years. This remodeling process is always ongoing. ONJ or osteonecrosis of the jaw results from a problem typically when there's been some trauma to the jaw or there's been a decreased blood flow to the jaw or there's been an infection that has developed under a tooth or around a tooth or there's been a tooth extraction or something like this. To heal that area, what again you need to have happen is the osteoclasts come in, they scoop out the bone, the osteoblasts come in and replace that bone. When patients are taking medications like the bisphosphonates, such as iridia or zometa or dinosumab, which is exjiva, it slows down the ability of those osteoclasts to scoop out the bone. When that occurs, that normal remodeling process cannot occur, and so it can take a longer time to heal that bone. Typically when patients are treated with these medications, either the bisphosphonates or the dinosumab, I recommend that they see their dentist regularly, at least twice a year they should try to have as good of oral hygiene as possible. Flossing, brushing, using a regular mouthwash, I recommend that if possible they try to avoid dental extractions, also to avoid dental implants. But if they do need to have any of those things occur, typically to consider taking an antibiotic or maybe three to four days before the extraction, for instance, and then three or four days afterwards, really to try to keep that area as clean as possible to allow any infection from getting in there while that normal remodeling process is going on, which is going to be slowed due to these medications which slow down the activity of the osteoclasts. So there's no real treatment for ONJ. The most important measurement is to prevent ONJ. I mentioned already prevention is making sure that you don't need any major dental work, like tooth extraction or root canal before you start bisphosphonates, and make sure that you have healthy teeth. Once you have ONJ, we would stop the bisphosphonates, we would give you a round of antibiotics, and we would hope that if the ONJ is in an early stage, that it will heal. Unfortunately, there's no specific treatment for ONJ. So there's no medication we can give our patients to heal ONJ. So make sure that you prevent ONJ. That is most important.