Author: Kerry Read, Physiotherapist.
Kerry is based in Brisbane Australia and has worked exclusively in the area of Craniomandibular Physiotherapy for 25 years. She currently works in Private Practice and runs seminars for Physiotherapists and other health Professionals about jaw issues. This overview provides information of a general nature and is not intended to replace medical consultation. Anyone with concerns is encouraged to seek help from their local health care specialist.
The Temporomandibular (TMJ / jaw) joints are located just in front of the ears, and can be felt moving as you open and close your mouth. They have synovial fluid, cartilage, and a disc, which acts as a spacer and shock absorber between the jawbone and the skull. Although the joint is a hinge, the TMJ does not drop open like a trap door. It has a more complex pattern where the jaw moves forward as it opens and the disc tracks smoothly forward to maintain the space. There are several small muscles within the mouth and some larger ones around the head and neck, which all work together to perform these movements.
TMJ dysfunction (TMD / TMJD / TMPDS) can occur when there is a problem with the bones, joints, muscles, or other soft tissues around the jaw. Because of it’s close muscular interaction it can also be affected by problems with the teeth, throat, neck, back, and even alterations in posture. One feature of its structure is that each side cannot operate independently, as both joints are joined to the same bone. A problem with one TMJ will always influence the other in some way.
Types Of Arthritis
The TMJ can be involved in both main types of arthritis. Osteoarthritis, the degenerative, ‘wear and tear’ type of arthritis, tends to come on slowly and is more common in later life. Rheumatoid, or inflammatory type arthritis of the TMJ, can develop rapidly, and at any age, in Juvenile, Psoriatic, Infective, Gout and Ankylosing Spondylitis. Pain is usually felt directly over the joints but can be in the ear, teeth, neck or head. The teeth may not seem to meet together properly and there may be pain on biting, chewing or swallowing. Mouth opening is usually reduced, and the jaw may veer off to one side, or refuse to glide smoothly to each side. It may be difficult to keep the mouth open for dental treatment.
The jaw may also make clicking or crunching noises on movement. There are two causes of this noise. Bony crepitus where the joint cartilage has degenerated and the bony surfaces are rubbing together is actually quite uncommon. Most people hearing their own jaw click would probably feel that this is exactly what is happening. However this is quite unlikely, especially if the problem is recent.
The commonest culprit when a jaw clicks is the disc. What you are usually hearing is the head of the jawbone clicking onto the disc and possibly off it again. The disc may be misshapen or the muscles out of sync, causing it to be in the wrong place. This is similar to the tracking problems we sometimes experience in the knee. The clicks from the TMJ usually sound much louder and more sinister as they are so close to the ear, and the head is very sensitive. It is also important to bear in mind that mild clicking, in the absence of pain is entirely normal. Without any other symptoms it is not something which requires treatment. Loud, persistent or painful clicking does need to be checked by your dentist, doctor or physiotherapist.
People who do need to pay attention to clicking jaw joints are those who may be ‘double jointed’. Patients with Benign Joint Hypermobility Syndrome (BJHS, JHS or Ehlers Danlos Syndrome) have an increased ‘play’ in their soft tissues which allows more than the usual amount of movement in a joint. They are susceptible to damage or injury to the jaw joint because of the excessive movement, and could also be more likely to suffer from inflammatory type arthritis.
Normal Jaw Movement
When the jaw is open to its widest extent it should accommodate the tips of the index, middle and ring fingers of one hand, held out straight and together. Remember, it’s your own fingers, so whether measuring a child or a large adult, individual variations are taken into account. The lower jaw should be able to slide smoothly forward so it juts forward beyond the top teeth. It should also be able to glide to each side, at least to the outer edge of each central top tooth.
Successful treatment of jaw problems depends entirely on a thorough evaluation by a trained health professional leading to an accurate diagnosis. To say someone has ’TMJ’ makes as much sense as saying ‘I have knee’! TMJ is not a diagnosis. It is sometimes assumed that all patients with jaw problems clench their teeth. Whilst this can be true, so can the opposite, where muscles are so inhibited by pain and swelling in the joint, they are hardly contracting at all. Therefore there is no one treatment method or ‘wonder therapy’ for TMJ dysfunction. The various types of dental splints, appliances, orthodontics, physical therapies, electrotherapy, exercises, heat and ice may all have their place in a well reasoned and targeted treatment plan.
Patients with inflammatory conditions, looking for additional pain relief may respond to TENS, using tiny dot electrodes. The area needs to be clean, flat and unblemished to ensure a good seal. The electrodes can be tried in various sites around the cheek area to find the most effective placement.
Topical anti-inflammatory creams such as Nurofen or Feldene can be used over the jaw, but patients already on other medications or with pre-existing conditions would need to check with their doctor before using. Capsaicin cream is another pain relieving alternative, which has shown some success in clinical trials. It can be made up by a compounding pharmacist in an oral formula or as a cream, such as Zostrix or Capzasin.
Self Help Strategies
Jaw problems can be eased or prevented by avoiding the following activities:
- Nail biting (the single worst culprit –stop it NOW!)
- Chewing pens and pencils
- Sleeping on your tummy
- Biting off sewing threads or fishing line
- Constantly chewing gum, Minties, Fantales or crunching ice
- Grinding the teeth and clenching the jaw
- Wide biting into huge apples, burgers, or overly chewy crusty bread.
- Biting into refrigerated chocolate with the front teeth
- Opening bottles with your teeth (ouch!)
- Constantly playing with the jaw or clicking it in and out.
- Rubbing too hard over the bony parts of your jaw- it can make them more tender
- Performing ‘party tricks’ (like ‘who can put a whole tennis ball in their mouth?’)
- Cup a hand under the jaw to restrict yawns and limit any opening past 3 fingers
- Make the sound ’N’, keep the tongue gently fixed in this spot while opening and closing the mouth. This helps the disc to track well and can eradicate a simple click
- Return the tongue to this position whenever you can
- Keep the nose clear to avoid mouth breathing
- Keep the lips gently together
- Never hold the jaw muscles clenched, allow them to relax
- Check for a relaxed jaw before drifting off to sleep
- Take warm water into the mouth and hold in the cheek to stretch these muscles
- Massage the jaw and head muscles in smooth circles
- Ask for rest breaks during long dental procedures, apply heat and rest afterwards.
- Never force the jaw open or push through sharp pain