Temporomandibular joint (TMJ) disorders

• Temporomandibular joint (TMJ) disorders are a group of medical conditions that cause the jaw joint (called the temporomandibular joint or TMJ) to be sore and painful. The TMJ connects the lower jaw, called the mandible, to the temporal bone of the skull, which is located in front of the ear on both sides of the head. The TMJ allows the jaw to move up and down and side to side. These movements are important for many functions, including talking, chewing food, and yawning.
• TMJ disorders are often divided into three categories: myofascial pain, internal derangement, and arthritis. Myofascial pain is the most common TMJ disorder. It occurs when the muscles that control the jaw are sore or tender. The cause of myofascial pain remains unknown. Internal derangement of the joint occurs when the joint becomes injured by a blow to the jaw. A TMJ disorder may occur if the injury causes the jaw to become dislocated, a disc becomes displaced, or the rounded ends of the lower jaw (called condyles) become damaged. Arthritis, which causes inflammation and swelling of joints, may also affect the TMJ. A patient may have one or more of these TMJ disorders, which may affect one or both sides of the jaw.
• Several other medical problems, including sleep disturbances, chronic fatigue syndrome, and a painful condition that affects the muscles and other soft tissues in the body (called fibromyalgia), have been associated with TMJ disorders. However, it is unknown if these health problems share a common cause with TMJ disorders.
• The exact number of people who have TMJ disorders remains unknown. However, as many as 10 million Americans experience symptoms related to TMJ disorders, according to the National institute of Dental and Craniofacial Research (NIDCR). For unknown reasons, these disorders occur more often in women than men. In general, TMJ disorders are most likely to develop in individuals who are 20-40 years old.
• Most patients with TMJ disorders only experience temporary symptoms, which often come and go. Although pain may occur when the jaw is not moving, it is generally worse when the jaw is being used. For many, the pain eventually goes away with little or no treatment. Some patients may benefit from self-managed care or nonsurgical treatments. However, for a small number of patients, TMJ disorders may cause serious long-term pain. In such cases, patients may need to undergo dental or surgical procedures to treat the symptoms.

• The cause of most TMJ disorders remains unknown. Some types of temporomandibular joint (TMJ) disorders appear to be caused by injury to the joint from a severe blow to the jaw or arthritis.
• Many behaviors, including frequently clenching the jaw or grinding the teeth (which may occur during sleep), poor posture that puts strain on the muscles and bones near the jaw, or other habits that overwork the jaw muscles (e.g. constantly chewing gum), may contribute to the development of TMJ disorders. However, further research is needed to definitively determine if these behaviors cause TMJ disorders. The National institute of Dental and Craniofacial Research (NIDCR) is currently performing a large study to help determine possible biological and genetic factors that may cause TMJ disorders.
• Overworking the jaw muscles has been shown to worsen symptoms of TMJ disorders.

• Symptoms of temporomandibular joint (TMJ) disorders vary among patients. Some patients may experience mild and temporary pain, while others may experience severe pain that may last for several years.
• Common symptoms of TMJ disorders include pain and soreness of the jaw (which may worsen when the individual chews food, talks, or yawns), pain in and around the ear, facial pain, an uneven bite or change in the way the lower and upper teeth fit together, jaw muscle stiffness, a clicking sound or grating sensation when the mouth is opened and closed (sometimes called jaw clicking), headache, tired facial muscles, and locking of the joint, which may temporarily limit the movement of the jaw.
• It is important to note that jaw clicking affects many individuals who do not have TMJ disorders. Individuals who do not experience pain or limited movement of the jaw when the jaw clicks most likely do not have TMJ disorders.

• There is no standard test to diagnose temporomandibular joint (TMJ) disorders. Because the exact cause of these disorders is often unclear, diagnosing the condition may be difficult. In general, the first step is to rule out other medical problems that may be causing symptoms, including sinus infections, ear infections, or nerve-related facial pain (called facial neuralgias).
• The healthcare provider then evaluates the TMJ for pain or soreness and listens for clicking or grating sounds that occur during jaw movement. The healthcare provider will also examine the joint to determine if the patient has limited motion of the jaw or an uneven bite. The presence of these symptoms indicates a TMJ disorder.
• If arthritis or an injury to the jaw is the suspected cause of a TMJ disorder, imaging studies, such as an X-ray, computerized tomography (CT) scan, or a magnetic resonance imaging (MRI) scan, may be performed. These tests provide pictures of the patient's jaw and may help the healthcare provider determine if the joint is damaged, injured, and/or inflamed. An MRI creates pictures of the soft tissues of the joint. Therefore, it can help healthcare providers determine if the TMJ disc is in the proper position. A CT scan shows the bones, allowing healthcare providers to determine if arthritis is present or the bone is injured.

• General: In some cases, the symptoms of a TMJ disorder may go away without treatment. If they persist, most experts agree that treatment should begin with conservative, nonsurgical therapies, which may include using hot or cold packs, eating soft foods, avoiding overuse of the jaw muscles, night guards, biteplates, and/or anti-inflammatory medications.
• If nonsurgical treatments do not reduce pain or discomfort, a healthcare provider or dentist may recommend corrective dental treatment, medications called corticosteroids, arthrocentesis (removal of fluid from a joint), or surgery.
• Exercises and stretches. A healthcare provider, dentist, or physical therapist can recommend specific exercises to stretch the jaw and reduce symptoms of TMJ disorders. Exercising the neck and shoulders may also help improve bad posture that may be contributing to the disorder. In addition, a healthcare professional may also teach the patient how to massage the jaw muscles to help reduce pain and soreness.
• Hot or cold packs: Doctors often recommend applying an ice pack to the side of the lower jaw (near the TMJ) for about 10 minutes. Next, the patient should perform some of the recommended stretches and/or exercises. Then, the patient should apply a warm towel or heat pack to the joint for about five minutes. This routine should be repeated a few times each day.
• Eat soft foods: Jaw pain is often the worst during eating because the jaw must open and close to chew food. Eating soft foods, such as eggs, yogurt, fish, beans, mashed potatoes, and cooked fruits and vegetables, may help reduce jaw discomfort during eating. It may also help to cut foods into smaller pieces. This is because less chewing is necessary when food is already cut into small pieces. The most difficult foods to eat are hard, crunchy, and chewy foods, such as bagels, raw carrots, hard rolls, and caramels.
• Biteplate: A plastic biteplate, also called a splint, may be recommended if the TMJ is misaligned. A biteplate is a plastic guard that is worn over the teeth. It is the most common treatment for TMJ disorders. It helps align the upper and lower jaws. In addition, biteplates may also help reduce the pressure in the joint, which reduces the harmful effects of clenching or grinding the teeth. As a result, patients experience less pain.
• Biteplates should not be used long term and should not cause permanent changes in the bite. Patients should visit their healthcare providers if a biteplate increases pain or discomfort.
• Night guard: Some individuals with TMJ disorders grind their teeth during their sleep. This behavior often worsens symptoms of jaw pain. A night guard is a plastic mouthpiece that is placed into the mouth during sleep. A night guard protects the teeth from becoming worn down and damaged when the individual grinds his/her teeth. Night guards are generally considered safe and are available at local drug stores.
• Anti-inflammatory medications: Medications called nonsteroidal anti-inflammatory drugs (NSAIDs) are often taken to reduce pain and inflammation associated with TMJ disorders. An example of a common NSAID is ibuprofen (Motrin® or Advil®).
• The frequency and severity of NSAID side effects vary. The most common side effects include nausea, vomiting, diarrhea, constipation, decreased appetite, rash, dizziness, headache, and drowsiness. The most serious side effects include kidney failure, liver failure, ulcers, heart-related problems, and prolonged bleeding after an injury or surgery. About 15% of patients who receive long-term NSAID treatment develop ulcers in the stomach or duodenum.
• Celecoxib (Celebrex®) has been taken by mouth to reduce more severe pain and inflammation. Celecoxib is currently the only COX-2 inhibitor that is approved by the U.S. Food and Drug Administration (FDA). Celecoxib is generally taken long term to manage symptoms.
• COX-2 inhibitors have been linked to an increased risk of serious heart-related side effects, including heart attack and stroke. Selective COX-2 inhibitors have also been shown to increase the risk of stomach bleeding, fluid retention, kidney problems, and liver damage. Less serious side effects may include headache, indigestion, upper respiratory tract infection, diarrhea, sinus inflammation, stomach pain, and nausea.
• Corrective dental treatment: In some cases, corrective dental procedures may be necessary to help reduce symptoms of TMJ disorders. For instance, if a patient has an uneven bite, a dentist may balance the surfaces of the teeth by grinding down some of the teeth, replacing missing teeth, or adding crowns or fillings. However, corrective dental treatment has not been scientifically proven to effectively treat TMJ disorders. In fact, some evidence suggests that this treatment may worsen symptoms of TMJ disorders. Therefore, patients should discuss all of the potential benefits and risks associated with medical procedures before making any decisions about treatments.
• Corticosteroid drugs: Corticosteroid drugs may be prescribed to relieve severe pain and inflammation caused by TMJ disorders. These drugs are typically injected into the joint for immediate pain relief.
• These drugs are generally very effective when used short-term. However, if these drugs are used for many months to years, they may become less effective and serious side effects may develop. Side effects may include easy bruising, thinning of bones, cataracts, weight gain, a round face, and diabetes.
• Arthrocentesis: During a minor surgical procedure, called arthrocentesis, a needle is inserted into the TMJ, and a small amount of fluid is removed. This technique has been shown to help relieve pain and inflammation in the joint. According to one study, 94% of patients with locked TMJs experienced long-term relief after arthrocentesis.
• After treatment, patients may experience minor bleeding in the joint, local bruising, and loss of skin pigment in the treated area. In rare cases, infections in the joints have developed.
• Surgery: If all other therapies are unsuccessful, a healthcare provider may recommend an oral and maxillofacial surgeon. However, failure to respond to other treatments does not necessarily mean that surgery is the best option.
• If a TMJ injury is causing symptoms of a TMJ disorder, patients may need to undergo surgery to repair or remove the disk between the mandible and temporal bone.
• In some cases, TMJ disorders that are caused by arthritis may lead to permanent joint damage. In such instances, joint replacement surgery may be necessary. During the procedure, the damaged joint is surgically removed and it is replaced with a plastic or metal device called a prosthesis.
• Researchers are currently studying the use of human tissue to replace damaged cartilage in the TMJ.
• No long-term human studies have evaluated the safety and effectiveness of surgical treatments for TMJ disorders. There are also risks associated with surgical procedures, including infection and bleeding. Patients should discuss the potential health risks and benefits of surgery with their healthcare provider.

C

Unclear or conflicting scientific evidence

• Acupuncture
  : The available evidence suggests that acupuncture may be comparable to other forms of treatments for temporomandibular joint disorder (TMJ). However, the studies that have been performed have major weaknesses that call into question the meaning of the findings. More studies of better design are needed for definitive recommendations.
• Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, medical conditions of unknown origin, or infections. Acupuncture should not be applied to the chest in patients with lung diseases or on any area that may rely on muscle tone to provide stability. Avoid use in infants, young children, or in patients with needle phobias. Use cautiously with bleeding disorders, neurological disorders, seizure disorders, or diabetes. Use cautiously in elderly or medically compromised patients. Use cautiously in patients who will drive or operate heavy machinery after acupuncture. Use cautiously if taking anticoagulants (blood thinners). Avoid if pregnant.
• Alexander technique
  : Preliminary case series data suggest that Alexander technique instruction may reduce symptoms in people with temporomandibular joint (TMJ) chronic pain. Well-designed human trials are necessary before a clear recommendation can be made.
• No serious side effects have been reported. It has been suggested that the technique may be less effective with learning disabilities or mental illnesses. The Alexander technique has been used safely in pregnant women.
• Chiropractic
  : Chiropractic care focuses on how the relationship between musculoskeletal structure (mainly the spine) and bodily function (mainly nervous system) affects health. There is currently not enough reliable scientific evidence to conclude the effects of chiropractic techniques in the management of temporomandibular joint (TMJ) disorders.
• Avoid with vertebrobasilar vascular insufficiency, aneurysms, arteritis (inflammation of the arteries), or unstable spondylolisthesis (a loss of spinal column alignment). Avoid use on post-surgical areas of para-spinal tissue. Use cautiously with acute arthritis, brittle bone disease, conditions that cause decreased bone mineralization, bleeding disorders, migraines, or if at risk of tumors or metastasis of the spine. Use extra caution in cervical adjustments. Avoid if pregnant or breastfeeding due to a lack of scientific data.
• Glucosamine
  : Glucosamine is a natural compound that is found in healthy cartilage. There is currently a lack of sufficient evidence to recommend for or against the use of glucosamine (or the combination of glucosamine and chondroitin) in the treatment of temporomandibular joint (TMJ) disorders.
• Avoid if allergic or hypersensitive to shellfish or iodine. Glucosamine may cause drowsiness, somnolence (drowsiness), or insomnia. Some reports suggest a link between glucosamine/chondroitin products and asthma. Use cautiously with asthma, diabetes, bleeding disorders, kidney disorders, or active peptic ulcer disease. Avoid if pregnant, planning to become pregnant, or if breastfeeding.
• Physical therapy
  : There do not appear to be any distinguishing effects on myofascial pain, temporomandibular disorders (TMJ), or function impairment in the available literature between arthroscopic surgery, arthrocentesis, and physical therapy. Most studies using physical therapy use it in combination with educational instruction. Additional study is needed to make a conclusion.
• Not all physical therapy programs are suited for everyone, and patients should discuss their medical history with a qualified healthcare professional before beginning any treatments. Physical therapy may aggravate pre-existing conditions. Persistent pain and fractures of unknown origin have been reported. Physical therapy may increase the duration of pain or cause limitation of motion. Pain and anxiety may occur during the rehabilitation of patients with burns. Both morning stiffness and bone erosion have been reported in the literature although causality is unclear. Erectile dysfunction has also been reported. Physical therapy has been used in pregnancy and although reports of major adverse effects are lacking, caution is advised nonetheless. All therapies during pregnancy and breastfeeding should be discussed with a licensed obstetrician/gynecologist before initiation.
• Spiritual healing
  : Recent research suggests that spiritual healing, in the form of shamanic healing, may treat pain from temporomandibular joint disorders (TMJ). More studies are needed to determine whether spiritual healing is an appropriate and effective treatment for TMJ disorders.
• Spiritual healing should not be used as the only treatment approach for medical or psychiatric conditions, and should not delay the time it takes to consider more proven therapies.
• TENS (transcutaneous electrical nerve stimulation)
  : Transcutaneous electrical nerve stimulation (TENS) is a non-invasive technique in which a low-voltage electrical current is delivered through wires from a small power unit to electrodes located on the skin. TENS is often used to treat pain as an alternative or in addition to pain medications. There is currently insufficient reliable evidence to recommend for or against the use of TENS to treat temporomandibular joint pain (TMJ).
• Avoid with implantable devices (e.g. defibrillators, pacemakers, intravenous infusion pumps, or hepatic artery infusion pumps). Use cautiously with decreased sensation (e.g. neuropathy) or seizure disorders. Avoid if pregnant or breastfeeding.

• Because the cause of many temporomandibular joint (TMJ) disorders remains unknown, there is no known method of prevention.
• However, because some types of TMJ disorders are associated with trauma to the jaw, individuals should take steps to reduce their risk of injuries. In order to reduce the risk of injury, individuals should wear protective gear when participating in contact sports, such as hockey or football. Individuals who ride motorcycles should wear helmets that have face shields.
• Individuals are encouraged to make lifestyle changes to avoid behaviors that may contribute to the development of TMJ disorders. Many behaviors, including frequently clenching the jaw or grinding the teeth (which may occur during sleep), poor posture that puts strain on the muscles and bones near the jaw, or other habits that overwork the jaw muscles (e.g. constantly chewing gum), may contribute to the development of TMJ disorders and should be avoided. Wearing a night guard during sleep may help protect the teeth from become worn down and damaged when an individual grinds his/her teeth. Night guards are available at local drug stores.