The temporomandibular joint (TMJ) is the joint connecting the mandible, or lower jaw, to the temporal bone of the skull. It is the hinge that allows the lower jaw to open and close and move from side to side, making chewing, eating, speaking, yawning and other functions possible.
Disorders to this joint can cause pain in the joint itself, the lower jaw bone and the muscles, ligaments and nerves associated with the joint. These conditions are referred to as temporomandibular joint disorder (TMD). Note that TMD may be referred to as TMJ, which is not strictly correct, as this refers to the joint itself. TMJ Disorder (TMJD) is also used to refer to TMD.
Symptoms
TMD symptoms include pain or discomfort to facial areas. The pain may occur on one or both sides of the head or jaw, and may be temporary or lasting months or years. The pain may be quite severe.
Common symptoms include may include the following:
Persistent pain in the face, jaw joint or the side of the head in or around the ear. The pain may be brought on simply by opening the mouth wide, chewing or talking. This pain may also extend to neck and shoulder areas.
Swelling in the joint itself or side of the face.
Difficulty in opening the mouth wide.
The jaw itself may actually become stuck in an open or closed position.
A sudden change in the way the upper and lower teeth of the jaw fit together.
Noises such as popping, clicking or grating in the jaw joint when opening or closing the mouth.
Headaches and toothaches. General aches and pains in ears, neck and shoulders.
Hearing problems and ringing in the ears.
Dizziness and sleep disorders.
How Common?
It is not known how many people suffer from TMD, but it is not uncommon, and thousands of Americans are diagnosed with it each year. There are estimates that more than 10 million Americans suffer from TMD.
A recent study suggests the facial pain and jaw movement problems symptomatic of TMD occur in 5 to 15 percent of Americans, with more women affected than men. TMD is reported most commonly in people 20 to 40 years of age.
Causes
The causes of TMD are unclear, but are commonly attributed to an existing disease condition, injury to the TMJ area, personal habits, physical and emotional stress and even poor posture or a combination of these and other conditions. However, it is also true that persons not displaying some of these listed conditions never develop the disorder.
Since symptoms of TMD involve the jaw joint itself or the muscles, nerves or ligaments associated with it, the causes are thus likely to be due to disturbances to those items, such as through persistent grinding of the teeth or a blow to the head, jaw, neck or shoulders. Causes may include the following:
Injuries to jaw or TMJ itself, or the soft tissue or muscle associated with these areas, including those lower down to neck or shoulders. For example, dislocations of the cartilage or ligaments of the temporomandibular ball and socket joint will induce stresses that may ultimately end up as TMD. This dislocation is what may produce the clicking or popping sounds in the jaw when opening the mouth or limit jaw movement.
Diseases such as osteoarthritis or rheumatoid arthritis in the TMJ itself. These diseases can cause the TMJ parts to fuse together.
Frequent teeth grinding. This can happen involuntarily during sleep and not just through stress or habit.
A malocclusion or “bad bite”.
Orthodontic treatment such as braces or head gear.
Physical stresses from repeated clenching or grinding of the teeth and flexing of jaw and facial muscles.
The wearing away of the cartilaginous disk in the TMJ.
Psychological stresses such as litigation, doing taxes, work deadlines, etc. These situations may lead to grinding or clenching of the teeth and flexing of facial muscles which put physical stresses on the TMJ.
Poor posture can contribute to facial, neck and shoulder tensions that may contribute to TMD.
Over short periods of time, physical and psychological stresses are not likely to be detrimental. TMD may result when these stresses occur over long periods.
Determining the cause of a TMJ problem is important, because it is the cause that guides the treatment.
Diagnosis
TMD can be difficult to diagnose due to sharing many symptoms with other conditions, including fibromyalgia, which may be related to TMD. A very careful examination of medical history as well as a physical exam by a medical professional (doctor or dentist) is required. Often diagnosis of TMD will require the services of both a physician and dentist and even other medical physicians and surgeons.
Patients should describe their symptoms to the physician in detail and should include:
Location of pain.
Intensity of the pain: how sharp or dull.
Duration of pain. Is it constant or intermittent?
Timing of the pain when strongest and mildest.
How long have you experienced the pain?
Do you engage in frequent behaviors that might contribute to a TMD condition such as chewing on gum, grinding your teeth, sitting for long hours or doing repetitive motions? Describe fully what these behaviors are.
Do you have good body posture, especially when undertaking physical activity, such as heavy lifting?
Have you ever injured your jaw in any way? Describe the injury, how it happened and how long ago.
Have you had any recent dental procedure or surgery?
In what sort of stress environment do you live and work? What is the frequency and duration of your high stress levels?
The doctor, or dentist, will closely observe the jaw as it is opened and closed. Jaw alignment is checked as is the bite, or how the teeth come together when the mouth is closed. A dentist may examine each tooth to ensure there are no obvious dental problems that might contribute to the symptoms.
The use of imagine technologies such as MRI and CT scans may be used to gain more detailed information on the tissues surrounding the jaw. X-rays are generally not useful in the diagnosis, but may help to rule out other conditions.
Risk Factors
Studies have been performed to determine TMD risk factors based on gender and age, but complexities in understanding the causes of TMD make correlations difficult to derive and narrow in their scope. People aged 30 to 50 are most likely to suffer from TMD.
In one study, chronic TMD risks increased in women between the ages of 18 and 44. The study did not focus on ages outside this age range. Other studies correlate increased risk of TMD during a woman’s early childbearing years.
Men in the 18 to 44 year old age group were also studied, but age appeared independent and unrelated to TMD incidence.
Low socio-economic status did not appear correlated to TMD incidence. Neither did it seem associated with changes in the control of pain perception in the nervous system.
Genetic variability was shown to contribute to chronic TMD. Patients with the condition had alterations of several genes known to influence stress response, psychological well-being and inflammation. Genetic variability contributes to chronic TMJD. Researchers found that chronic TMJD patients had alterations in several genes, including some known to influence stress response, psychological well-being, and inflammation.
Joint and Muscles Commonly Affected
Temporomandibular joint disorders will affect parts of the jaw, temporal area of the skull and the muscles, ligaments and nerves which are associated with the operation of the jaw.
The jaw bone ends in the mandibular condyle, which articulates to the temporal bone of the skull in a location called the articular fossa, which is just forward and below each ear. This joint is cushioned by cartilage which smoothes the movement of the jaw ends against the skull. Mandibular muscles work the jaw up and down and side to side as needed.
Many muscle groups are needed to control jaw movement, including primarily the masseter and temporalis muscles. Many difference ligaments are also present. The joint is enervated by the mandibular branch of the trigeminal nerve.
Given the many bone, muscle, ligament and nerve components involved, and that the temporomandibular joint is the most constantly used joint in the body, it should be no surprise that the effects of the disorder may be widely felt as pain or swelling, both in the specific joint area, and also in surrounding tissues of the face, neck and shoulders.
Treatment
For initial or short-term treatment of the disorder, simply use an over-the-counter or prescription pain medicine. This may provide pain relief, but will generally not fix any inherent problem causing the condition. Ice packs may be used to counter swelling of jaw or facial areas. If pain persists, despite such simple treatment, professional medical advice should be consulted.
Severe TMD cases may require surgery to repair the joint. However the pain associated with most TMD cases can be handled without the need for surgery, either by a medical professional or by oneself.
Once TMD disorders are correctly diagnosed, appropriate treatment can be provided. The treatments range from mild dental and medical care to complex surgery. A diagnosis may dictate treatment via short-term, non-steroidal anti-inflammatory drugs (NSAIDs) which include ibuprofen (Advil, Motrin) and naproxen (Aleve) for pain. Minor tranquilizers may be used for muscle relaxation, especially at bedtime to reduce spasms and pain. Injections of local anesthetic and corticosteroid injections may be required for more severe cases. A Biteplate can help bring upper and lower jaws into alignment, reducing stresses on the TMJ. Splint therapy and stress management counseling may also be helpful.
In some cases, fluid can be drained from the jaw to reduce swelling and associated pain.
Treatments include dental procedures such as “occlusal adjustment” and “equilibration”, physiotherapy or surgery. “Occlusal adjustment” involves adjusting the biting surface of teeth by grinding the enamel. However various reviews of the procedure have found little evidence to show it can prevent or relieve temporomandibular disorders.
Equilibration is a similar dental procedure that may provide relief. This involves selective reshaping of the top surfaces of the teeth to stabilize and balance the jaw joint.
TMD symptoms may eventually require the services of an oral and maxillofacial surgeon, who is a specialist in the areas of the mouth, teeth and jaws. The oral and maxillofacial surgeon is trained to correctly diagnose the problem.
Treatment of TMD may eventually require special imaging studies of the joints with referrals to other dental or medical specialists or a physical therapist.
Supplements may help reduce pain, rebuild cartilage in the joint and generally improve motion of the jaw. These supplements include:
Glucosamine helps rebuild joint cartilage and in some cases is just as effective in reducing pain as pain relief medications such as ibuprofen (Advil, Motrin). Glucosamine is frequently combined with chondroitin sulfate to reduce the risk of bleeding, especially if it is being taken with blood thinners. However, glucosamine may interfere with cancer treatment medications, so consult a doctor before use, if treatment for other conditions is underway.
Vitamin C is also used by the body to make cartilage, so it may improve the motion of the jaw. There are no scientific studies on vitamin C for TMD issues and they may interact with other medications.
Calcium and magnesium may help the jaw muscles relax. There are no scientific studies using them for TMD problems and they may interact with other medications, herbs or supplements. It may also effect the heart and blood pressure so consult a doctor before use.
Herbs have been used for generations in treating disease and disease symptoms. However their effects are not well studied and they can interact with other herbs, medications or supplements.
Reduction of muscle spasms may be accomplished with the use of Cramp bark (Viburnum opulus) and lobelia (Lobelia inflata). A small tincture of each herb is rubbed on the skin of the joint. They are not to be taken orally or applied to skin where cuts or scrapes occur.
Professional homeopaths may use the remedies listed below to treat TMD pain symptoms. Actual treatment can depend on a patient’s physical, emotional and psychological attributes, so the specifics of treatment may vary accordingly.
Causticum – for burning pains
Hypericum perforatum – for sharp shooting pains
Ignatia– for tension in the jaw
Kalmia – for face pain, especially with other joint pains or arthritis
Magnesia phosphorica– for muscle cramps
Rhus toxicodendron – for pains that feel better in the morning and in dry weather, and worse after movement or in wet weather
Ruta graveolens – for pains from overuse or injury
There is good evidence that acupuncture can successfully treat the pain of TMD. Combined with a technique that burns mugwort over specific acupuncture points, the pain therapy is boosted.
“Contrast hydrotherapy” uses alternating hot and cold water applications to affected areas to lower inflammation and provide relief from pain. It is said to promote healing as well. Hot packs are ice wrapped in soft cloth are applied to the area, alternating with three minutes host and one minute cold. This is repeated three times for one set and two to five sets are performed per day.
Chiropractors have been used to treat TMD, although its use has not been well studied. It is believed that manipulation of the joint and surrounding areas of the upper spine help the TMJ move smoother and with a wider range of motion. Chiropractic massage may help decrease muscle spasms, relieve pain and prevent symptoms from returning.
Biofeedback is used to teach the patient how to reduce muscle tension through relaxation and visualization. Sensors are placed on the jaw with a machine indicating the amount of tension in the jaw muscles. The patient learns, using the machine to provide visual feedback, to reduce the amount of tension around the jaw. Once the patient learns the technique, the relaxation and visualization techniques can be applied independent of the machine.
Finally, proper posture, attained through movement therapy, can aid in reducing TMD symptoms. There are two types of movement therapies for treating TMD problems: Alexander technique and the Feldenkrais method.
The Alexander technique teaches how to properly align the head, neck, and spine, and move the body. It is aimed at relieving tension in head and jaw muscles, which may reduce the symptoms of TMD.
The Feldenkrais method teaches how to recognize bad posture habits and movements that cause your body to tense. It is designed to make the patient more aware of how the body moves, helping to develop an inner awareness of the body. It is popular with those who frequently perform repetitive motions that may lead to overuse injuries.
Outlook
Unfortunately, disorders of the temporomandibular joint are not yet well understood, and much remains for study. Future studies need to determine effectiveness of current treatments, while research may lead to more effective treatments using arthroplasty, arthroscopy and new medications or medical devices.
Findings on the correlation between chronic TMD and gene alterations may provide new possibilities in the development of drugs to treat the pain.
The cause and severity of the temporomandibular joint disorder may determine the outlook for the patient, as well as how well treatment recommendations are followed.
Prognosis
The biological complexity of TMD means healthcare professionals can not easily determine if a patient will recover in time given a treatment, or will be faced with a long term fight against a chronic disease.
One reason treatment can be so difficult is due to a complex biological interplay involving factors ranging from complexity in pain transmission, its redirection and amplification en route to the brain to the presence of other painful conditions such as fibromyalgia and fatigue that can mask or change the TMD symptoms.
Some researchers have suggested the best scientific entry point to examine TMD is during its earliest stages, before the full-blown complexity of advanced disease clouds the investigative picture. Such studies are currently few in number.
Fortunately, most cases of TMD can be successfully treated. This is especially true when the condition is diagnosed early and accurately, and the treatment schedule is closely followed. About 75 percent of people with TMD find relief if they follow a treatment plan with more than one treatment. In rare cases, degenerative joint disease may result from long-term teeth clenching or grinding, injury, infection, or connective tissue disease.
Symptoms of TMD usually do not last long, and frequently, symptoms resolve themselves with little or no treatment, although the symptoms can recur.
It is important to follow up treatments with regular visits to a health care provider to ensure the treatment plan is working, and to prevent the recurrence of TMD symptoms.
Prevention
People who have a poorly aligned bite or missing teeth can have related health problems, such as frequent headaches or sleep disorders, because their jaw muscles must work harder to bring the teeth together, straining the surrounding jaw muscles.
The following recommendations may help prevent temporomandibular joint disorders or help prevent their recurrence.
Avoid extreme jaw movements such as gum chewing or yawning.
Avoid biting pencils, pen caps, fingernails, and cuticles.
Avoid foods that are difficult to chew. Eat softer foods high in flavonoids such as cooked fruits and vegetables. Flavonoids are plant-based antioxidants that may help decrease joint pain.
Avoid saturated fats, fried foods, and caffeine. These foods can increase inflammation.
Avoid treatments (if possible) that cause permanent changes in the bite or jaw, such as tooth crown or bridge work, orthodontics and repositioning splints.
Avoid surgical treatments (if possible). There have been no long-term studies to test the safety and effectiveness of these procedures.
Learn relaxation techniques to reduce muscle tension and stress and improve sleep.
Maintain proper posture. Use proper body ergonomics, for example when lifting, by using the legs rather than back.
Don’t spend long hours sitting or in unchanged body positions. Stretch the body periodically to relieve repetitive stress on the body, in particular the head, face, neck and shoulder regions.