Essentially there are two areas in the jaw that may give rise to pain and they are the jaw joint (TMJ) or jaw muscles. The pain derived from these two areas is in medical terminology referred to as Musculo-skeletal Pain.
It is not strictly possible to differentiate between joint and muscle pain based on a description of the pain, although both would tend to be described as a dull aching sensation with jaw pain at times causing sharp episodes at times with jaw movement and sometimes with no apparent provocation. Both pains may be aggravated by use of the jaw such as with chewing or biting, but equally in some it may not be affected by anything in particular. So the fact that you have a pain that does not increase when you use the jaw does not necessarily mean that you do not have a jaw related cause for your pain.
Most people with jaw pain will probably have a combination of joint and muscle pain. Both pains may occur at a relatively early age (less than 10 years of age) but more commonly makes its appearance in or after the teenage years which most might generally consider a little early to start getting chronic joint or muscle pain. Given its often early age appearance many would ask the question:
What causes jaw pain?
The answer is that in most cases we do not have an answer to that. Most people do not recall a particular incident that led to pain, although this can occur obviously. It is likely that some of us have an inherent “weakness” that makes us prone to developing pain in the joint or muscles in the absence of injury and equally at a relatively early age.
Given that orthodontic treatment (braces) is most often carried out in the teen years and that many will have a first experience of jaw pain at this age it is not unreasonable to find that teenagers may complain of developing jaw problems following orthodontic treatment. This is more than likely a coincidence and it is unlikely that the movement of teeth during orthodontic treatment may injure the jaw. It is possible that changes in tooth position can change the loading or stresses on the joint and muscles in susceptible people, but there is no evidence to substantiate this. Importantly it must be remembered that the vast majority of people undergoing orthodontic treatment do not develop jaw problems.
People will sometimes relate that jaw problems developed shortly after having a dental treatment and often this involves a lengthy form of treatment where the patient of necessity had the mouth open wide for a prolonged period. In this instance it is likely that the development of jaw problems had more to do with a prolonged period of wide opening than with the actual procedure itself.
Possibly for similar reasons a patient who has a sudden onset jaw problem may relate that it began following a particularly wide opening of the jaw for example to eat a large sandwich!
Tooth grinding is also commonly cited as a cause of jaw problems, whereas this may have a role to play it is unlikely that it is a sole cause of jaw problem. Interesting to note most severe tooth grinders do not develop significant jaw problems! Tooth grinding probably has a role to play and no doubt once damage or injury has occurred it is likely that grinding is at least partly responsible for aggravating the situation, wherein what may begin as a simple injury is prevented from healing by ongoing nighttime tooth grinding or clenching and thus becomes a persistent or chronic problem.
(See section on tooth grinding)
JAW JOINT PROBLEMS
Jaw joint problems can be divided into pain and mechanical problems or a combination of both.
Jaw Joint Pain is caused by inflammation in the joint with generally an unknown cause except perhaps that which is caused by an arthritic condition. As with all painful joints rest can be effective in allowing healing, but in the presence of tooth grinding during sleep complete rest may never be obtained and hence the tendency for joint pain once it is established to be slow to settle.
Anti-inflammatory medication similar to ibuprofen (nurofen) can be useful in some at bringing about a resolution, but needs to be used in relatively large doses for a prolonged period of time to work as an anti-inflammatory as opposed to its more common role as a pain killer. These medications need to be used cautiously and sparingly due to their potential to cause side-effects.
Acrylic splints or bite guards are a very effective way of alleviating joint pain and allowing healing. A correctly constructed and balanced splint would be expected to completely relieve pain if worn nightly for one year and at this point should no longer be required once healing has taken place.
Soft splints made of a flexible material are unlikely to be successful except in the early stages of jaw pain and may often aggravate the problem. These are often provided by dentists as they are very simple to construct and occasionally effective. To be most effective splints need to be made of a hard acrylic material and fitted with very precise biting contact against the opposing teeth both when biting and moving the jaw as during grinding. Incorrectly made acrylic splints may not eliminate pain completely or some will find if not worn indefinitely pain returns once it is not worn, indicating the joint has not healed as hoped.
Joint injection using steroids may also help to reduce inflammation and is useful in certain situations and with severe joint pain that is proving to be slow to improve. Although often effective, repeated use can be associated with damage to joint tissue.
Jaw Mechanical Problems (joint dysfunction) is due to displacement of the disc within the joint. This should not be confused with joint dislocation as it is often incorrectly described. Dislocation is an unusual injury in the jaw joint. Most disc displacements occur without particular injury and again are common at a relatively young age. The most common position for a disc to displace to is in front of the condyle. In its simplest form this may cause a clicking sensation as the jaw opens. Displacement can result in pain in some instances and then may require treatment. Where the disc remains in a forward position it may prevent full opening a situation that is referred to as jaw locking.
Problem disc displacement or locking may be treated again with a correctly designed acrylic splint or in cases where there is pronounced disc displacement surgery may be required. It is an accepted fact that surgery should be reserved for intractable cases that have not responded to conservative management.
Jaw Joint Arthritic Conditions just as with all other joints in the body the jaw joint can develop arthritic problems. Just as with other joints these can be a part of a generalised condition such as rheumatoid arthritis or psoriatic arthritis. In both these cases the patient will probably have problems with other joints and will usually already be seeing a rheumatologist.
Osteoarthritis is a far more common condition in jaw joints. The cause of arthritis is joints is poorly understood, but in some it may be induced by a previous injury. In some joints artificial or prosthetic joints are used to replace badly damaged joints. Replacement joint surgery is extremely rarely required in cases of jaw osteoarthritis. In many cases the damage caused can be extreme in which case pain may or may not be present. However the condition is rarely if ever debilitating or incapacitating in the long run although it can at times be extremely painful it more often than not resolves spontaneously. This is borne out by the fact that very few patients are seen in the 70-80year age group and fewer still in the over 80year age group. This is likely due to the non-cartilage nature of the disc which gives it greater healing powers than discs in other areas such as in the spine or knees.
Treatment for osteoarthritis is similar to that discussed for other painful joint conditions. Paracetamol is useful for reducing pain levels and anti-inflammatory medications can also be useful as can steroid injections into the joint in cases with severe pain.
JAW MUSCLE PAIN
A large part of the face and the side of the head is occupied by our jaw muscles and with the onset of pain in these we can find we develop very widespread pain in the head and often extending to the neck and shoulder area. In addition muscle pain tends to radiate or refer to adjacent areas. Jaw muscle pain is the most common form of facial pain outside toothache.
When suffering from jaw pain we will not be specifically aware of having sore muscles. The pain is typically a vague aching sensation in the face which may or may not be increased by chewing or biting. Many times patients will assume that they have a toothache and in many cases the pain may seem to be from a single tooth or sometimes from a group of teeth. Where teeth have been removed there may often be a sense of pain in the gum where there is no teeth. This can give rise to a suspicion that part of the root has been left behind following a prior extraction. Wisdom teeth are often suspected as being the culprit where in fact pain is in fact caused by jaw muscles. Unnecessary extraction of wisdom teeth and replacement of perfectly good fillings is a common sequel to incorrectly diagnosed jaw muscle pain. This is often done at the insistence of the patient who is convinced that the pain is tooth related.
Chronic muscle pain is a poorly understood phenomenon. We are all aware of athletes and sports persons who develop muscle injuries which heal with rest. However jaw muscle along with back and neck muscles are inclined to linger after injury and in many cases seem to arise with no specific cause or injury. It would appear that the design of muscles in these three areas which are essentially responsible for maintaining posture are a different make up to other muscles and are inclined to develop chronic ongoing pain. Hence we know that many people suffer from back pain for example. In some with back or neck pain there is a skeletal or joint problem which is causing pain due to pressure on a nerve, whereas in many others there appears to be no underlying skeletal problem or else this has long since healed up and the individual is left with un-remitting muscle pain.
Jaw muscle pain is similar to above although in jaw joint pain direct pressure on a nerve is not a cause of pain as such and joint pain results only from inflammation in the joint with muscle pain often developing as a direct result of the joint pain. Thus in most people with jaw pain we see muscle pain combined with joint pain. Once again ongoing chronic muscle pain can develop in some, in some cases lasting for many years.
The effect of jaw muscle pain very commonly has secondary effects. Where the temporalis muscle in the temple area is involved a common feature is tension-type headache. So we find many with jaw problems developing chronic tension-type headache that is slow to resolve with medication treatment, but may show dramatic improvement with treatment of the jaw problem.
Jaw muscle pain and neck and upper back pain are very strongly interlinked with one often leading to the other. This can lead to a situation where someone has neck pain that does not respond to treatment, for example with physiotherapy, as the neck pain is developing secondary to the jaw pain. The result being that the neck pain only resolves once the jaw problem is dealt with. Conversely some people, who suffer a neck injury such as whiplash, may develop jaw pain as a secondary issue and in this instance the opposite situation may occur where the jaw pain does not resolve until the neck pain is successfully dealt with.
Treatment of jaw muscle pain does not often respond to physiotherapy as do other musculo-skeletal pains, possibly due to the fact that night-time grinding can prevent an improvement by constantly overusing the painful jaw joint and muscles.
Where jaw muscle pain is occurring without joint pain attention to postural problems and simple stretching exercises can be beneficial both from the point of relieving pain and repairing damaged muscles.
[See section on: self-help for jaw and neck problems]
As tooth clenching and grinding is tending to overload the painful areas and is beyond our self-control it is often necessary to protect the sore muscles from their harmful effects. In just the same way that a balanced hard acrylic splint protects painful joints so too painful muscles can heal can heal if protected from overuse. Yet again it is important to have a correctly made splint as a simple “hard bite-plate” may not be helpful. Again it should be noted that soft flexible type splints although easily made may aggravate rather than relieve muscle pain.
Pain medications such as paracetamol (Panadol) and anti-inflammatories may have limited benefit as chronic muscle pain is not caused by inflammation. Some suggest that their use is beneficial in relieving pain and thus allowing more effective use of exercise therapy and other physical measures.
Chronic pain medications such as an older type of anti-depressant medications can be effective in difficult to manage muscle pain, but probably is not warranted in the absence of physical measures. Muscle relaxing medications such as Valium probably also have very limited benefit in jaw pain and have the distinct disadvantage of being highly addictive. Valium may be useful if used very short term (matter of days) in cases of true muscle spasm, although this condition is probably very rare in the jaw area.
Fibromyalgia and ME are generalised muscle conditions which by definition lead to muscle pain which affects all areas of the body and are usually associated with other symptoms such as sleep difficulty and chronic fatigue. These conditions are inherently very difficult to manage and may be treated as for more conventional jaw pain. Chronic pain medications often have an important role to play in their management.
(Fibromyalgia information: http://www.fibroireland.com)