Temporomandibular Joint Disorder

Temporomandibular Joint (TMJ) Disorder

By Lori Montgomery, MD, CCFP and Kate Gerry, BSc, PT, BPE

Introduction

The temporomandibular (say: tem-puh-ro-man-DIB-yuh-ler) joint is the place where your lower jaw (mandible) attaches to your skull. It is the joint that allows you to open and close your jaw. There is a shock-absorbing disc between the two parts of the joint (similar to the discs in your spine). There is also a set of specialized muscles that control movement of the joint. Pain and abnormal function in this joint can cause problems with eating and speaking, and make it difficult to sleep.

Signs and symptoms

  • pain over the temporomandibular joint on one or both sides
  • headache
  • neck pain
  • burning, shooting, electric-shock-like facial pain
  • numbness or tingling around the jaw
  • pain with chewing, clenching, or yawning
  • clicking or locking of the jaw
  • reduced range of motion (either when opening the mouth or when moving the jaw from side to side)
  • a change in the way the upper and lower teeth fit together

Causes

There are a number of reasons to have symptoms of temporomandibular joint (TMJ) disorder. They fall into three main groups, although many patients have two or three of them at the same time:

  1. myofascial
  2. structural
  3. degenerative arthritis
  4. congenital


Myofascial

Myofascial changes in the muscles of the jaw that cause pain and changes in function. This type of pain is similar to the pain of fibromyalgia, and the two conditions often go together. We do not know what causes this to happen, although it sometimes happens after a trauma such as a motor vehicle collision, especially one that involves a whiplash-type injury. Sometimes these patients have a history of clenching the jaw, or grinding the teeth - but sometimes the symptoms start with no clear reason at all.

Structural

Sometimes a disc is displaced, the joint is dislocated, or one of the bones is broken. This happens most often after a significant trauma, like a serious motor vehicle collision.

Degenerative

Degenerative arthritis can happen in this joint, in the same way that it happens in other joints in your body. This happens as you age, although it is more likely to happen if the joint has been injured in some way.

Congenital

Some syndromes can cause facial deformities, which affect the joint.

Diagnostic tests

The best way to diagnose TMJ disorder is not clear. The way that you describe your symptoms and the results of a physical exam of the jaw, neck, and shoulders by a doctor or physiotherapist are likely the most important parts of the diagnosis. Some tests may be done, such as an X-ray to make sure that there are no fractures or other problems with the bones of the jaw. If you are referred to a dentist or other provider with a specialized approach to TMJ disorder, magnetic resonance imaging (MRI) may be done to guide treatments like injections or surgery.

Treatment approach

Sometimes, the pain will settle with simple things like eating soft foods for a while, or putting ice or heat on the joints. When it becomes more persistent or disabling, more invasive treatments may be required. There is no clear evidence to tell us which treatment is best. However, so most experts recommend using treatments that do not cause irreversible changes to the teeth or the bite (i.e avoid surgery, if possible).

Splints

Splints are often used to stabilize the jaw in TMJ disorders. These should be worn for a limited period of time, and should not cause permanent changes to the bite. They are intended to relieve symptoms of TMJ (not to cure it), and so should never cause or increase pain.

Non-drug therapies

There is a strong link between neck pain and TMD, so strengthening and stretching of the neck muscles is also important. There are physiotherapists with expertise in treating TMD. They can provide exercises to strengthen the muscles around the jaw. Some patients find the following things helpful as well:

  • intramuscular stimulation (IMS)
  • acupuncture
  • biofeedback
  • nutritional therapy
  • transcutaneous electrical nerve stimulation (TENS)

Non-drug therapies

Studies have shown that non-drug therapies can help to reduce pain levels and enhance pain coping. These include:

  • relaxation
  • meditation
  • activity pacing
  • cognitive behavioural therapy

These self-management strategies can help you to improve your function so you can do more and enjoy life more.

Medicines

Medicines are sometimes helpful to reduce pain levels, improve sleep, and help you to function better. These may include anti-inflammatories, acetaminophen, or weak opioids. Some of the Medicines that can help fibromyalgia may also help TMJ pain. These include:

  • tricyclic antidepressants (such as amitriptyline or nortriptyline)
  • gabapentin or pregabalin
  • tramadol or other opioid-like Medicines (such as morphine)
  • serotonin-norepinephrine reuptake inhibitors (such as venlafaxine or duloxetine)

Botox (botulinum toxin type A) has been used at times to treat TMJ disorder. It is the subject of intense research, and may prove to be useful for some people. It has not been officially approved for use in TMJ disorder, however.
Sometimes a combination of local anaesthetic and steroid can be injected into the joint. There are not many providers who perform this procedure.

Surgery or splints

Surgery or splints that permanently alter the bite are available in many centres. They are appropriate for a small number of patients with TMJ disorder. There are no long-term studies that evaluate the safety and usefulness of these approaches, however. They have the potential to make pain worse, so they should be approached with caution. Research is ongoing into how to develop invasive techniques that are most effective with the least potential to cause harm.

For more information

Web sites

Web MD 
www.webmd.com

The TMJ Association, Ltd.
www.tmj.org

American Pain Foundation
www.painfoundation.org

Pain.com
www.pain.com

TRIP Database (Resources for Evidence Based Medicine)
www.tripdatabase.com

National Institute of Neurological Disorders and Stroke
www.ninds.nih.gov

References

National Institute of Dental and Craniofacial Research/Office of Research on Women’s Health. TMJ Disorders., National Institutes of Health, NIH Publication No. 06-3487. Updated December 05, 2008.

Dimitroulis, G. The role of surgery in the management of disorders of the temporomandibular joint: a critical review of the literature. International Journal of Oral and Maxillofacial Surgery. 2005;34(2)107-13.