Bone Loss In the Jaw Joint (TMJ)

One of my biggest concerns for many of my patients is obvious bone loss within the jaw joints.  I see this in patients as young as 12 years old.  Unfortunately, this bone loss is always permanent, and it can have a significant affect on the alignment of the jaw, which can result in a severe bite problem.  In the jaw joint, this type of bone loss is closest to osteoarthritis.  We rarely see rheumatoid arthritis in the jaw joint, unless the patient has evidence of rheumatoid arthritis in other joints.  In my practice, I see jaw joint bone loss in over half of my patients.  In many cases, this bone loss may be present without any pain or dysfunction in the joint.

There are several theories regarding the cause of this bone loss.  One thing we know is that the bone loss never occurs until after there has been a dislocation of the disc in the joint.  This disc fits between the ball and socket of the joint, and is designed to prevent contact between these two structures.  Causes of dislocated discs can include trauma or genetically weak ligaments.  In addition, long-term clenching and/or grinding of the teeth can result in damage to the joint ligaments.  Once the disc is displaced, bone loss can ensue if there is over-loading of the joint.  Clenching and/or grinding of the teeth are the cause of jaw joint over-loading.

Recent research has demonstrated several systemic factors that can predispose females to jaw joint bone loss.  One of these is low vitamin D.  The other is low estrogen.  Low estrogen can occur if there is a history of irregular or missed periods, or if the person is taking birth control pills containing a synthetic estrogen, known as ethanyl-estradiol.  When one of these deficiencies is documented by a blood test, the bone loss in the jaw joint may be defined as "idiopathic condylar resorption."  We recommend testing for these deficiencies in our female patients with demonstrated bone loss. 

This jaw joint bone loss does not necessarily mean the patient also has arthritis in other joints.  Unless they have pain, stiffness, or swelling in other joints, I do not usually refer them to a rheumatologist.

Treating arthritis in jaw joints can be challenging.  Conservative (non-surgical) treatment is indicated, because surgery on jaw joints with demonstrated bone loss can result in significant complications.  Specifically, conservative treatment may include the use of a jaw splint designed to prevent over-loading of the TMJ.  In addition, we focus on all the potential causes of clenching or grinding, including stress, poor sleep, and other harmful habits.  We also recommend a number of supplements, which have been shown to reduce the risk for bone loss in the TMJ. 

In most cases, this bone loss will eventually arrest itself and stabilize, if the patient follows treatment recommendations.  We take follow-up CT scans, to confirm that the surface of the ball of the jaw joint is re-forming cortical bone.  Once this occurs, and there has been no additional bone loss for at least 6 months, we then re-evaluate the bite problems that have occurred as a result of the bone loss.  If the bone loss has been severe, extensive bite treatment is usually necessary, including orthodontic braces and sometimes surgery to re-align the jaw bones.

Here are some signs you can look for which may indicate that you are experiencing bone loss in your jaw joints:

• Catching or locking in your jaw joint, which prevents normal opening or closing.
• Grinding or gravel-like noise in the jaw joint when moving the jaw.
• A change in the bite relationship, which prevents you from touching on one side or the other when you close your mouth.

I am constantly looking for research articles and continuing education seminars on jaw joint bone loss and how to prevent it.  One of these articles is posted on our site.