What is it?
Osteonecrosis of the jaw is defined by an area in the mouth that has not closed for more than eight weeks and has bone showing beneath it. The bone has died; because the gum that should cover it is not healing, the area stays open and is constantly exposed to bacteria.
There are two main backgrounds to it. The first is the group of medicines used to slow the breakdown of bone; they are given for osteoporosis and as part of some cancer treatments, and at cancer doses the risk is clearly higher. The second is radiotherapy given to the head and neck; radiotherapy permanently reduces the blood vessels within the bone.
The trigger is most often a tooth extraction, a surgical procedure or a spot where a denture rubs; it can also appear with no procedure at all. Pain is not always present. The first thing noticed may be a bad smell, a rough patch that the tongue catches on, or a sore that will not heal.
Signs
You will not necessarily have all of these at once.
Why does it happen?
- 01
Medicines that slow the breakdown of bone
These medicines slow the bone's renewal cycle. The jaw is the most vulnerable area because it is in constant contact with the bacteria of the mouth and is operated on often. How high the risk is depends on why the medicine is being used, its dose and how long it is taken.
- 02
Radiotherapy to the head and neck
Radiotherapy permanently reduces the network of blood vessels inside the bone. Bone with a poor blood supply cannot repair itself after an injury; this is why the risk in a jaw that falls within the treated area continues even years later.
- 03
Extraction, surgery and trauma from a denture
Every procedure that reaches the bone creates a demand for healing. When the bone cannot meet that demand, the wound does not close. A spot where a poorly fitting denture rubs can lead to the same result.
- 04
An infection already present in the mouth
Inflammation at a root tip, advanced gum disease and poor oral hygiene all raise the risk. This is why getting the mouth clean before the medicine or the radiotherapy starts is the most decisive step in this picture.
How does it progress?
- At risk
No exposed bone
The period when you are taking the medicine or have had radiotherapy but have no exposed bone in your mouth. The work to be done is to deal with teeth that need treatment in a planned way and in good time.
- Early
Exposed bone, no symptoms
The bone is visible, but there is no pain and no sign of infection. Mouth care, an antiseptic mouthwash and regular review come first; there is no rush into surgery.
- Infected
Pain and infection are added
Redness, discharge and pain appear around the exposed bone. An antibiotic and surface cleaning come into play; the aim is to limit how far the area spreads.
- Advanced
Findings that reach beyond the bone
A discharge channel opening through the skin, a jawbone that fractures on its own, or wide bone loss can be seen. The decision is made in hospital, together with oral and maxillofacial surgery.
How is it treated?
The priority is to keep pain and inflammation under control and to slow the growth of the exposed area. At an early stage the approach is most often gentle cleaning, an antiseptic mouthwash and regular review. Cutting the exposed bone away widely is not the right answer in every case; in some patients it makes the area larger.
Once infection is added, antibiotics, removal of the dead pieces of bone that have separated from the tissue around them and, where needed, surgery in hospital come into play. These decisions are made by oral and maxillofacial surgery together with the patient's oncology, endocrinology or rheumatology doctor.
Do not stop your medicine on your own decision. Whether it is paused is solely the decision of the doctor who prescribed it, and stopping the treatment carries risks of its own. The dentist's role is to spot the sign early, to time any planned procedures in discussion with that doctor, and to keep your mouth care going.
- Exposed bone under the gum that has not closed for weeks
- Increasing pain and swelling in the area, with discharge opening through the skin
- Numbness in the lower lip that has just started
- Fever and the mouth opening less and less
How is it prevented?
- When a bone medicine or head and neck radiotherapy is planned, have a dental examination before treatment starts wherever that is possible; teeth that need taking out are dealt with beforehand.
- Give the full list of medicines you take, and your radiotherapy history, at every dental appointment.
- Do not try to adjust the places where your denture digs in or rubs yourself; come in and have the fit corrected.
- Keep up your mouth care and your regular check-ups; early treatment is the one thing that reduces the chance of an infected tooth ending up needing extraction.
Frequently asked questions
- If I stop my medicine, will this get better?
- Stopping the medicine does not reverse necrosis that has already formed, and stopping it on your own is risky; it has consequences of its own, such as a bone fracture or the underlying disease progressing. The decision to pause is made only by the doctor who prescribed it, in discussion with your dentist.
- Does this happen to everyone who takes these medicines?
- No. At osteoporosis doses it is uncommon; at cancer treatment doses, and in jaws that have had radiotherapy, it increases clearly. Your own risk depends on the type of medicine, how long you take it and the state of your oral health.
- What is done if an extraction is needed?
- An extraction is not absolutely ruled out; its timing and technique are planned. The mouth is cleaned up beforehand, the procedure is kept as gentle as possible and healing is watched closely. The decision is taken by the doctor managing your treatment and your dentist together.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.