The temporomandibular joint is located where the lower jaw bone connects with the skull. This joint’s function is essential for talking and eating, and people use it around 2,000 times each day. Some people develop temporomandibular joint disorders, which are commonly referred to as TMJ. These disorders cause people to experience dysfunction and pain in the joint and the muscles that are used to move the jaw. The National Institutes of Health estimates that more than 10 million people in the U.S. suffer from TMJ, and women are likelier to develop this condition than men.
Understanding the temporomandibular joint
The temporomandibular joint is located on both sides of the jaw where the bone connects to the skull. These joints are very complex and work with a variety of muscles to allow the jawbone to slide in and out, rotate, and move side to side while eating and talking. When the jaw bone and joints are correctly aligned, smooth muscle movements involved in swallowing, yawning, talking, and chewing work well. However, when they are not properly aligned or synchronized, people may suffer multiple problems.
What is TMJ?
Temporomandibular joint disorders are a group of disorders involving the temporomandibular joints, the jaw muscles, and the nerves. Issues that prevent the joints, bones, and muscles from working together properly can cause people to develop TMJ. Temporomandibular joint disorders include chronic pain in the muscles and connective tissues, jaw or disc dislocations, and degenerative diseases affecting the temporomandibular joint. Some people may suffer from more than one type of TMJ.
Causes of TMJ
The temporomandibular joint uses both sliding motions and a hinge action to function. The bones of the joint are covered by cartilage and include a small disc to absorb shock and make the movements smooth. People can develop TMJ when their discs move out of their proper placement or erode. They can also suffer TMJ when damage occurs to the cartilage or when their joints are injured by an impact or blow such as in an assault or car accident. In some cases, the cause of TMJ is difficult to pinpoint.
Some of the risk factors that might increase the risk of TMJ include the following:
- Chronic clenching or grinding of the teeth
- Connective tissue disorders that can impact the temporomandiublar joint
- Injury to the jaw in an assault, fall, or motor vehicle accident
A TMJ accident-induced injury might result in a rear-end car accident in which a victim suffers whiplash. In a rear-end collision, an occupant of the front vehicle might have his or her head and neck thrown violently forward before overextending as they are propelled back. This violent movement can cause injuries to the muscles in the neck and jaw and affect the muscles and connective tissues that help the temporomandibular joint to function properly. People might also suffer TMJ related to an accident when they strike the dash or another object with their faces, injuring the temporomandibular joint by the force of the blow.
Symptoms of TMJ
TMJ can cause many different symptoms. Some of the most common symptoms of TMJ include the following:
- Painful soreness or discomfort in the jaw
- Chronic headaches
- Pain spreading through the face, neck, shoulder, back, and behind the eyes
- Earaches or ringing unrelated to an infection of the inner ear
- Popping or clicking in the jaw
- Painful jaw locking
- Reduced ability to move the mouth and jaw
- Grinding or clenching of the teeth
- Tooth sensitivity unrelated to an oral disease
- Tingling or numbness
- Changes in how the lower and upper teeth fit together
Since the symptoms of TMJ might have overlapping symptoms with other types of conditions, people should see their doctors to be properly diagnosed.
How is TMJ diagnosed?
Since the symptoms associated with TMJ also can be caused by other conditions, doctors might start by ruling out other medical problems that can cause the same symptoms. Doctors or dentists might talk to their patients about the symptoms they are experiencing and complete medical examinations of their jaws. During an examination, a doctor might do the following things:
- Listen to the jaw and feel it as the patient opens and closes his or her mouth
- Ask the patient to move the jaw and mouth to observe his or her range of motion
- Palpitate areas around the jaw to identify painful areas
If a problem is suspected, a doctor might order dental x-rays to take a closer look at the jaw and teeth. Imaging studies such as CT scans might be ordered to provide a detailed picture of the bones of the temporomandibular joint. If the doctor suspects issues with the disc or cartilage, he or she might order magnetic resonance imaging to examine those tissues.
In some cases, doctors will perform TMJ arthroscopy to properly diagnose TMJ. During this process, the doctor will make a small incision and insert a cannula into the joint space. An arthroscope will then be inserted through the cannula to allow the doctor to examine the area and its surrounding structures to make a proper diagnosis.
How is TMJ treated?
TMJ symptoms sometimes dissipate on their own. However, when people suffer ongoing symptoms, their doctors might recommend a variety of different treatments, including medications, non-surgical procedures, or surgery. Doctors might also discuss lifestyle changes that can help to alleviate the symptoms of TMJ.
Doctors might recommend several types of medication, including anti-inflammatory and pain medications. If over-the-counter medications do not sufficiently relieve the person’s pain, he or she might be prescribed stronger pain relievers to be used for a short duration. Tricyclic anti-depressants might also be prescribed in low doses. While they are normally used to treat depression, they can also help with insomnia and pain at low doses. Patients who suffer muscle spasms in their temporomandibular joints might also be prescribed muscle relaxers for a few days or weeks for pain relief.
Non-surgical treatments might also be used in conjunction with medication. These might include wearing mouthguards, physical therapy, and counseling. Mouthguards are appliances that fit over the teeth. In physical therapy, a patient might learn exercises designed to strengthen and stretch the jaw muscles while also receiving treatments such as moist heat, ice, and ultrasound. Counseling is used to help people understand behaviors that might make the pain worse so that they can avoid them. For example, a patient might be taught to avoid grinding his or her teeth, biting his or her fingernails, or leaning on his or her chin.
If non-surgical approaches do not work, a doctor might recommend surgical procedures to correct the underlying problem causing the pain. The doctor might perform a minimally invasive procedure called arthrocentesis. In this procedure, a small needle will be inserted into the joint to irrigate the joint with fluid to rinse way inflammatory byproducts and debris.
Open-joint surgery might be recommended in some cases when conservative treatments have not worked, and the disorder appears to be caused by structural problems in the joint itself. This surgery is called arthrotomy, and it is used to replace or repair the joint. Since open-joint surgery carries more risks than minimally invasive methods, people should carefully consider the pros and cons before agreeing to undergo an arthrotomy procedure.
Finally, some people benefit from corticosteroid injections into the temporomandibular joint. In some cases, doctors might recommend injections of botulinum toxin type A into the muscles the patient uses to chew to relieve pain.
People will want to discuss any procedure recommended by their doctors to treat TMJ. They should ask about the risks and benefits as well as other treatment alternatives that might be available.
In addition to procedures and treatments, people might also want to make some adjustments to their lifestyles to help reduce the symptoms of TMJ. The following things might help to alleviate some of the symptoms of TMJ:
- Don’t chew gum, and avoid chewy or sticky food. Cut food into smaller pieces, and choose softer foods.
- Perform exercises to strengthen and stretch the jaw muscles, and massage them.
- Apply heat or ice to the affected side of the face.
People who suffer from TMJ might also benefit from alternative or complementary medicine to help manage chronic pain, including acupuncture, meditation, or biofeedback.