Definition
The temporomandibular joint or TMJ is the joint on either side of the head, just beside and a bit below the eyes. It is the joint that connects the maxilla and the mandible and is also known as the “chewing joint”. It is a typical ball and socket joint with the ball part being on the mandible or lower jaw. There is a cartilaginous disc between the bony parts of the jaw that helps cushion the joint and creates a smooth, sliding surface between the two halves of the joint. It is the joint we use for yawning, talking, chewing and biting things. Tendons and muscles are attached to the joint to help the joint move properly.
Causes of TMJ disorder
The TMJ is stressed whenever there is malocclusion of the teeth or something wrong with the chewing aspects of the face. Teeth grinding or teeth clenching can cause TMJ distress. This is also known as bruxism. Bruxism increases the wear of the cartilage in the joint and you begin to hear clicking or have locking of the jaw. Repetitive gum chewing or nail biting can lead to TMJ disease. If you are born with malocclusion, the damage to the TMJ happens quite quickly in life. Trauma to the jawbone can contribute to the TMJ being “off” or not in the right position.
Just being under stress can cause the TMJ to become tight and wear away at the cartilage. Stress often causes people to clench their teeth or grind their teeth. Even jobs that require you to hold your telephone between your face and your shoulder can cause the TMJ to be out of balance. Spasms and overuse of the muscles of the jaw can slowly damage the joint itself.
Symptoms of TMJ Disorder
Eighty percent of patients experiencing TMJ disorder will complain of a headache of varying qualities. About 40 percent have pain in the face that is often worsened by opening and closing the mouth. Cold air or cold in air conditioning can increase the tension and spasm in the temporomandibular joint.
About half of all patients with TMJ disorder will have pain in the ear without any sign of an actual ear infection. The pain is often felt as being below or in front of the ear. Because of this, it is not dentists but ear doctors that make more actual diagnoses of TMJ disease. Some patients get treated over and over for an ear infection when, in fact none is there.
If you have TMJ disorder, there are often popping, grinding or crunching sounds—also called crepitus. Some of the crunching can actually be felt when putting your fingers over the TMJ joint. Interestingly, 40 percent of patients with TMJ disorder feel a bit dizzy or off balance—similar to vertigo. A sensation of fullness in the ear is experienced by 33 percent of patients, worse when flying in airplanes. This is believed to be because there is spasm of the muscles of the middle ear. It may be affecting the opening or closure of the Eustachian tube.
Tinnitus or ringing of the ears is also common and has no obvious etiology. This symptom is seen in about a third of patients with TMJ disorder.
Complications of TMJ Disorder
If TMJ is allowed to progress, the cartilage wears away and it can become so bad that bone rubs on bone. This results in severe arthritis of the joint, significant pain in one or both joints and, unless the pain is tolerable, a new joint must be put in the place of the real joint.
Prevention of TMJ Disorder
In order to prevent serious joint disease, you need to treat the underlying cause of the TMJ disorder. This might mean wearing a splint to prevent teeth clenching and teeth grinding. If malocclusion is the cause of the problem, orthodontic hardware (braces and such) might have to be used to create a normal bite. Once the bite is fixed, there should be no more damage to the temporomandibular joint.
Treatment of TMJ Disorder
In milder cases of TMJ disorder, doctors and dentists prescribe heat and ice to the affected areas (alternating), anti-inflammatory medications, and a soft dental diet. Biofeedback can be used to decrease the tension in the bite and to keep the mouth open as much as possible. Medications such as naproxen or ibuprofen can be used to reduce inflammation. Some doctors do local injections of cortisone medications in order to reduce the spasms and inflammation. Physical therapy using electrical stimulation often works as well. Doctors often use an acrylic appliance or splint that is usually used at night to prevent grinding in one’s sleep. Orthodontics are used to put the bite into a normal position can help if the damage to the TMJ isn’t so severe. Surgery is done as a last resort. The damaged joint is cut out and a plastic and metal joint is used to replace the damaged joint. Ligament tightening can also make the joint more stable.