Temporomandibular Joint (TMJ) Syndrome

Picture of Temporomandibular Joint (TMJ) Syndrome

Temporomandibular joint (TMJ) syndrome is a pain in the jaw joint that can be caused by a variety of medical problems. The TMJ connects the lower jaw (mandible) to the skull (temporal bone) in front of the ear. Certain facial muscles that control chewing are also attached to the lower jaw. Problems in this area can cause head and neck pain, facial pain, ear pain, headaches, a jaw that is locked in position or difficult to open, problems with biting, and jaw clicking or popping sounds when you bite. The temporomandibular joint syndrome is also referred to as the temporomandibular joint disorder. Overall, more women than men have TMJ syndrome.

The TMJ is comprised of muscles, blood vessels, nerves, and bones. You have two TMJs, one on each side of your jaw.

Muscles involved in chewing (mastication) also open and close the mouth. The jawbone itself, controlled by the TMJ, has two movements: rotation or hinge action, which is opening and closing of the mouth, and gliding action, a movement that allows the mouth to open wider. The coordination of this action also allows you to talk, chew, and yawn.

If you place your fingers just in front of your ears and open your mouth, you can feel the joint and its movement. When you open your mouth, the rounded ends of the lower jaw (condyles) glide along the joint socket of the temporal bone. The condyles slide back to their original position when you close your mouth. To keep this motion smooth, a soft disk of cartilage lies between the condyle and the temporal bone. This disk absorbs shock to the temporomandibular joint from chewing and other movements. Chewing creates a strong force. This disk distributes the forces of chewing throughout the joint space.

The TMJ connects the lower jaw (mandible) to the skull (temporal bone) in front of the ear.

TMJ syndrome can be caused by trauma, disease, wear and tear due to aging, or oral habits.

• Trauma: Trauma is divided into macrotrauma and microtrauma. Microtrauma is internal, such as grinding the teeth (bruxism) and clenching (jaw tightening). This continual hammering on the temporomandibular joint can change the alignment of the teeth. Muscle involvement causes inflammation of the membranes surrounding the joint. Teeth grinding and clenching are habits that may be diagnosed in people who complain of pain in the temporomandibular joint or have facial pain that includes the muscles involved in chewing (myofascial pain). Macrotrauma, such as a punch to the jaw or impact in an accident, can break the jawbone, cause dislocation of the TMJ, or damage the cartilage disc of the joint. Pain in the TMJ can be brought on by dental work whereby the joint is stretched open for extended periods of time. Massage and heat application after the dental procedure can be helpful.
  • Bruxism: Bruxism, or teeth grinding, is a habit that can result in muscle spasm and an inflammatory reaction that can cause the initial pain. Changes in the normal stimuli or height of the teeth, misalignment of teeth, and repetitive use of chewing muscles may cause temporomandibular joint changes. Generally, someone who has a habit of grinding his or her teeth will do so mostly during sleep. In some cases, the grinding may be so loud that it disturbs others.
  • Clenching: Someone who clenches continually or bites on things while awake. This might be chewing gum, a pen or pencil, or fingernails. The constant pounding on the joint causes the pain. Stress is often blamed for tension in the jaw, leading to a clenched jaw.
• Osteoarthritis: Like other joints in the body, the jaw joint is prone to arthritic changes. These changes are sometimes caused by the breakdown of the joint (degeneration) or the usual wear and tear of normal aging. The degenerative joint disease causes a slowly progressive loss of cartilage and formation of new bone at the surface of the joint. Cartilage destruction is a result of several mechanical and biological factors rather than a single entity. Its prevalence increases with repetitive microtrauma or microtrauma, as well as with normal aging. Immunologic and inflammatory diseases contribute to the progression of the disease.
• Rheumatoid arthritis: Rheumatoid arthritis causes inflammation in joints and can affect the TMJ. As it progresses, the disease can cause the destruction of cartilage, erode bone, and eventually cause joint deformity. Rheumatoid arthritis is an autoimmune disease. It causes disease in a variety of organs with features of persistent joint inflammation. It occasionally affects the TMJ, especially in young children.
• Other causes of TMJ syndrome include infection of the joint, cancer, and bone deformity that occurs at birth.

Symptoms of TMJ syndrome are ear pain, ringing in the ears (tinnitus), and hearing loss.

• Pain in the facial muscles and jaw joints may radiate to the neck or shoulders. Joints may be overstretched and muscle spasms can occur. The pain may occur with talking, chewing, or yawning. The pain usually appears in the joint itself, in front of the ear, or it may move elsewhere on the face, scalp, or jaw and lead to headaches, dizziness, and even symptoms of migraines.
• TMJ syndrome may cause ear pain, ringing in the ears (tinnitus), and hearing loss. Sometimes people mistake TMJ pain for an ear problem, such as an ear infection, when the ear is not the problem at all.
• When the joints move, they may produce sounds, such as clicking, grating, and/or popping. Others may also be able to hear the clicking and popping sounds. This means the disc may be in an abnormal position. Sometimes no treatment is needed if the sounds do not cause pain.
• The face and mouth may swell on the affected side.
• The jaw may lock in a wide-open position (indicating that it is dislocated), or it may not open fully at all. Also, upon opening, the lower jaw may deviate to one side. Some people may experience favoring one painful side or the other by opening the jaw awkwardly. These changes could be sudden. The teeth may not fit properly together, and the bite may feel odd.
• Muscle spasms associated with TMJ syndrome may cause difficulty swallowing.
• TMJ syndrome can also cause headaches and dizziness, potentially leading to nausea and/or vomiting.
• Some individuals with TMJ syndrome may have a history of poor dentition or emotional distress.

Ongoing studies conducted by the National Institute of Dental and Craniofacial Research (NIDCR), part of the U.S. National Institutes of Health, are focused on evaluating risk factors for TMJ syndrome in healthy individuals. Initial results have identified a group of physiological, psychological, sensory, and genetic and nervous system factors that may increase the risk of developing TMJ syndrome. New findings will allow us to better understand the onset and progression of TMJ syndrome. Furthermore, novel ways to diagnose and treat the condition can be developed. Below are some risk factors that have been identified:

Gender: Women are at higher risk of developing TMJ syndrome compared to men. Additionally, there may be differences in how women and men respond to pain and to pain medications.

Age: Studies of individuals between the ages of 18-44 show that the risk to develop TMJ conditions increases for women. This has been noted especially for women during their childbearing years. For men ages 18-44, there was no increased risk.

Pain tolerance: Studies suggest that people who are more sensitive to mildly painful stimuli have an increased risk of developing TMJ syndrome.

Genetics: There is some indication that genes related to stress response, psychological health, and inflammation may increase the risk for TMJ syndrome.

Chronic pain: Those who suffer from chronic pain conditions such as lower back pain and headaches may be at increased risk for TMJ syndrome.

• Acute TMJ symptoms and signs may last anywhere from a few days to a few weeks and then disappear after the injury or cause of discomfort has resolved.
• For a chronic TMJ condition, the symptoms can be ongoing with episodes of sharp and/or dull pain that occur over an extended period of time (months to years).

Occasional pain in the jaw joint or chewing muscles is common and may not be a cause for concern. See a doctor if your pain is severe or if it does not go away. You should also see your health-care professional if it hurts to open and close the jaw or if you have difficulty swallowing food. Treatment for TMJ syndrome ideally should begin when it is in the early stages. If the condition is identified early, the doctor can explain the functioning of the joints and how to avoid any action or habit (such as chewing gum) that might aggravate the joint or facial pain.

If your jaw is locked open or closed, go to a hospital's emergency department.

• The open locked jaw is treated by sedating you to a comfortable level. Then the mandible (upper jaw) is held with the thumbs while the lower jaw is pushed downward, forward, and backward. This maneuver is usually done by the Emergency Department physician or an ear, nose, and throat (ENT) specialist.
• The closed locked jaw is also treated by sedating you until you are completely relaxed. Then the mandible is gently manipulated until the mouth opens.

• Medical history: In diagnosing your jaw problem, the doctor will ask the following questions:
  • What kind of pain do you have?
  • Is it an ache, a throbbing pain, or a sharp stabbing pain?
  • Is the pain continuous or intermittent?
  • Can you outline the area of pain on your face with your finger?
  • What helps to alleviate the pain? What aggravates the pain?
  • Do you grind or clench your teeth? Do you bite your nails or chew on any objects, such as pens or pencils?
  • Do you hold the telephone with your shoulder against your ear for a long time?
  • Do you chew gum often? For how long?
  • Do you have any oral habits that you have not mentioned?
• Physical examination: During the physical examination, the doctor will examine your head, neck, face, and temporomandibular joints, noting any of the following:
  • tenderness (pain) and its location;
  • sounds, such as clicking, popping, grating;
  • the mandible (lower jaw) range of motion, whether it is easy to open and close if it can move from side to side and forward-backward without any pain;
  • your assessment of pain on a scale from 0 (no pain) to 10 while the jaw is being manipulated;
  • wear and tear on the buccal cusps of the mandibular teeth, especially the canine teeth;
  • rigidity and/or tenderness of the chewing muscles; and
  • how your teeth align together: are the teeth normal, is there an open bite, crossbite, or overbite; have you had dental restorations; and is there a facial bone deformity.

Depending on the what doctor suspects as the cause, he/she may order blood tests that include a white cell count and other tests to rule out lupus, rheumatoid arthritis, or gout as a cause of the TMJ syndrome.

• Imaging: X-rays may be taken of the mouth and jaw.
• Ultrasound may also be ordered to assess the function of the TMJ. It is a useful tool to assess the inside of the TMJ.

If the diagnosis of TMJ syndrome is not clear or some other disorder is suspected, CT or MRI scans may also be obtained The MRI scan can help assess the soft tissues and the inside of the joint. A CT scan can help assess the bony structures and muscles. Experts believe that in doubtful cases, MRI is the study of choice as it is useful in evaluating TMJ disease.

In rare cases, if all the above tests fail to make a diagnosis of TMJ syndrome and pain still persists, the surgeon may use a needle to clean and irrigate the joint (arthrocentesis).

In the majority of cases, TMJ syndrome is self-limiting. Most of the symptoms disappear in two weeks once the jaw is rested There are a variety of options for treating TMJ syndrome at home.

• Anti-inflammatory and pain medications such as aspirin or acetaminophen (Tylenol) or ibuprofen (Motrin, Advil) may provide relief.
• Eat a diet of soft foods.
• Avoid chewing gum and eating hard candy or chewy foods. Do not open your mouth wide. Your doctor may show you how to perform gentle muscle stretching and relaxation exercises.
• Stress-reduction techniques may help you manage stress and relax your jaw along with the rest of your body.
• Apply warm compresses on the area of pain. Home therapy includes mandible (lower jaw) movements, such as opening and closing the jaw from side to side. Try this after a warm compress is applied for 20 minutes. The lower jaw movements should be repeated three to five times a day, five minutes continuously each time, for about two to four weeks. A gentle massage of the area can also be beneficial.

For chronic TMJ syndrome, a team approach is usually required. This may include a dentist, ENT surgeon, pain specialist, physiotherapist, and a primary care physician. Modalities used to relieve pain and restore the function of the TMJ may include the use of splints, physical therapy, psychological counseling, acupuncture, hypnotherapy, and arthrocentesis.

Medications that may be used to relieve pain may include tricyclic antidepressants, muscle relaxants, and prescription-strength painkillers. Botulinum toxin (Botox) can be used alone or in combination with other treatments to relieve the muscle spasm and pain.

There are several types of appliances to treat bruxism. These splints are custom made and help redistribute the force of the teeth while biting. The doctor may fit you with a splint or bite plate. This is a plastic guard that fits over your upper or lower teeth, much like a mouth guard in sports. The splint can help reduce clenching and teeth grinding, especially if worn at night. This will ease muscle tension. The splint should not cause or increase your pain. If it does, do not use it.

Surgery

Surgery is never the first choice of treatment for TMJ syndrome. Arthrocentesis entails the use of a needle to clean and irrigate the joint. During the procedure, the surgeon may inject a local anesthetic or a steroid into the joint. Arthroscopy surgery is done when there is suspicion of an internal problem with the TMJ. It does require anesthesia and has a high success rate in resolving pain.

Physical therapy

Anyone with recurrent or chronic TMJ syndrome is referred for physical therapy. The therapist can help restore joint mobility, increase muscle strength, and relieve pain.

Other treatments

A variety of other treatments are also available for chronic TMJ syndrome and include friction massage, transcutaneous electrical nerve stimulation (TENS), and cognitive behavior therapy.

• The National Institute of Dental and Craniofacial Research (NIDCR) advises that if surgery is recommended, you seek other independent opinions before proceeding. Generally, experts recommend the most conservative and reversible treatment possible based on a reasonable diagnosis.
• NIDCR advises that other irreversible treatments have not been proven effective and may potentially worsen the condition. These include orthodontia to change the bite, restorative dentistry, and adjustment of the bite by grinding down teeth to bring the bite into balance.

Follow your doctor's specific instructions for taking any medication prescribed and for home care with compresses or gentle jaw exercise.

• You may be instructed to follow up with a specialist such as an oral and maxillofacial surgeon, a general dentist, or a pain-specialist physician. Maxillofacial surgery may be necessary when there is poor alignment of the jawbone (mandible) with the skull bone.
• Dentists are often the first to diagnose TMJ syndrome. They are familiar with conservative treatments. Specially trained facial pain experts can be helpful in diagnosing and treating TMJ syndrome.

• If you tend to have occasional bouts of jaw pain, avoid chewing gum or biting on objects, such as pens or fingernails. Avoid eating hard or chewy food. When you yawn, support your lower jaw with your hand.
• Avoid large bites while eating.
• Regularly massage your jaw, cheeks and temple muscles.
• If you feel spasms, apply moist heat.
• Maintain good sleep posture with neck support.
• Avoid cradling the phone between your shoulder and neck.
• See your dentist if you grind your teeth at night or find yourself clenching your jaw. The dentist can make a splint for you.

Most people do well with conservative therapy, such as resting the jaw or using a mouth splint. The success of treatment depends on how severe the symptoms are and how well you comply with treatment.

Only about 1% of those with TMJ syndrome require joint replacement surgery.