TMJ 5

Can you see TMD on dental X-rays?

The diagnosis of TMD is generally based on the presence of the characteristic clinical signs and symptoms that the patient presents upon examination. In other words, for the most part, the patient is telling us that he or she is suffering from a group of subjective symptoms, like headaches, neck aches, sensitive teeth etc. Using what the patient tells us, we then begin to look for more objective signs of the disorder such as clicking of the joints, deviation upon opening and closing the mouth, and periodontal involvement.

There is, however one objective sign that is visible upon dental x-rays which may lead the dentist to suspect that the patient is "addicted" to parafuntional habits such as bruxing and clenching the teeth.

The image above shows several lower teeth. The thing to notice is the relative widening of the periodontal ligament toward the crown of the teeth (yellow arrows). Note that instead of being a relatively thin dark line between the bone and the tooth, as denoted by the blue arrows, it appears to widen as it progresses up the root toward the crown. This widening is called "funneling" of the periodontal ligament, and is a sign that the patient tends to place great pressure on the teeth. The presence of funneling on dental x-rays generally does mean that the patient is bruxing, but it does not necessarily mean that the patient actually needs treatment for TMD. Whenever I see this objective sign on an x-ray, I generally ask the patient if he or she is suffering from any of the cardinal symptoms of TMD. If he or she answers in the negative, then no treatment is needed. If the answer is yes, then the patient is told the options and sent home to read this web page. If the patient believes the symptoms are severe enough to warrant treatment, then we proceed from there.

The relationship between the sinuses and TMD

The X-ray at the right shows the upper back teeth and their relationship to the maxillary sinuses which are located just above them. As you can see, the roots of the back teeth are in very close approximation to the sinuses, and it is easy to imagine that the nerves inside the teeth must be supplied by blood vessels and nerve fibers that traverse through the floor of the sinuses. Thus, if the sinuses are inflamed and swollen because the patient has a cold, allergies, or a sinus infection, the nerves inside the teeth will be affected. Therefore, a sinus problem can cause low grade toothaches in the top, back teeth.

The hallmark of sinus related toothaches is pain on sudden movements of the head, like jogging, or jumping off a curb. Sometimes just sitting up quickly can cause a low grade jolt in the top back teeth. When a dentist suspects that tooth pain is related to a sinus problem, he or she will frequently prescribe a decongestant and an antibiotic as an empiric treatment for the toothache. This means that he treats the sinuses on the assumption that they are the root cause of the toothache, and if the treatment works, then the diagnosis is presumed to be correct.

But sinus problems frequently lead the patient to bruxing habits. The teeth "feel" strange due to the conditions imposed on them by the sinus condition, and the patient begins to clench and grind unconsciously because it makes the teeth feel better. This bruxing habit can lead to phantom pain toothaches as well as headaches, ear aches neck stiffness and all the other symptoms of TMD discussed below.

The relationship between TMD, snoring and sleep apnea

Many people snore at night. This happens because the muscles in the neck and throat relax while a person is asleep, and this allows the tongue, soft palate and epiglottis to contact the back of the throat causing a constriction of the airway. When this happens, the close approximation of these tissues causes them to vibrate against each other producing the sound characteristic of snoring. It is a problem especially prevalent in short necked people, older men, and obese persons of either sex. For a more detailed discussion of snoring and all of its ill effects (as well as treatment options) please see my page on Sleep apnea and snore guards.

In many instances, the obstruction caused by the relaxation of the throat muscles is so exaggerated that the patient is unable to breath at all. This condition is known as obstructive sleep apnea, and it causes the patient either to awaken as many as several hundred times a night, or to "jerk" into a much lighter sleep phase in which the muscles regain some of their waking tone. In either case, sleep is very poor and the patient spends much of his waking hours being very sleepy or actually falling asleep at inappropriate times.

In addition to daytime effects, however, the inability to properly breath while sleeping produces some nighttime physiological effects which can be pretty devastating. Heart rate slows, blood pressure rises, and the body's skeletal muscles can become quite active. This is especially true of the muscles of mastication (chewing muscles). Thus people who do not breath properly at night due to obstructive sleep apnea are likely to grind and clench their teeth in their sleep. This causes all the symptoms of TMD discussed on this page, including headaches, tired jaw muscles and earaches upon waking in the morning. Therefore, persistent morning headaches upon waking may be a sign of obstructive sleep apnea, and patients who sleep poorly, know they snore and have these symptoms may be well advised to visit a physician and arrange to have a sleep study to discover if they are at risk for major medical complications arising from their obstructive sleep apnea.

The Relationship between TMD and Migraine Headaches

Recently, there has been a paradigm shift in the scientific understanding of the etiology and treatment of migraine headaches. While migraines differ from tension headaches in intensity and in related symptoms, they may be triggered by clenching the teeth, just like tension headaches. The evidence for this is as follows:

Jaw clenching muscles in migraine sufferers tend to be about 70% larger in volume than in persons without migraine.
Jaw clenching muscles in migraine sufferers can generate much higher biting forces than the jaw muscles in control subjects.
Migraine suffers who experience their headaches upon waking show evidence of nocturnal bruxing.
Both migraine suffers and persons who experience tension headaches show tenderness to palpation (pressing and kneading with the fingers) in the muscles of mastication (those muscles that close and grind the teeth) during and following their headaches while control subjects do not.

The difference between tension headaches and migraines is as follows:

Migraine sufferers experience so much pain, and often vertigo that they are often incapacitated and need to lie down, while tension headache suffers can often control their pain with analgesics and continue to operate during their attacks.
Migraine suffers exhibit one or more of the following symptoms during an attack:
- Nausea due to vertigo
- Sensitivity to light
- Sensitivity to sound

Therefore, it is apparent that there is a relationship between bruxing and clenching the teeth, and migraine headache. The standard of care in the treatment of migraine now includes some of the modalities used to treat TMD, especially the use of deprogrammers.

The relationship of TMD and illegal drugs

The designer drug Ecstasy (E) as well as methanphedamines (speed--diet pills), cocaine and crack are popular street drugs and are used because they are stimulants and cause the abuser to feel wired, or more awake and alive. These drugs, and especially ecstasy, have become extremely popular among ravers. Raves are all night parties in which there are lots of lively young people, lots of loud music and entertainment, and lots of drugs. Ravers who use Ecstasy have one thing in common. They tend to grind their teeth mercilessly. Ecstasy and cocaine, like all central nervous system stimulants cause muscular hyperactivity, and the muscles involved in grinding and clenching of the teeth are especially affected. This is such a common phenomenon that it has become fashionable among ravers to carry and use pacifiers in order to control the habit and the attendant pain and tooth wear it causes. The damage to the teeth can become quite severe, and the pain from the headaches and earaches can cause these people to seek out potent pain relievers such as narcotics which are generally available in the same social circles in which ecstasy is popular. Thus multiple addictions are common among ravers.

Meth mouth
Bruxing is also a major problem for meth addicts. Click on this image for more.

The TMJ section used to occupy a single page on this website, but due to its extreme length, it has been broken up into seven separate pages. A good understanding of the Temperomandibular joint, occlusion and their associated disorders may be gained by reading them in order.Next Page==>Organic Joint disease

TMJ Pages 1, 2, 3, 4, 5, 6, 7