The temporomandibular joint (TMJ) is the small joint located in front of the ear where the skull and lower jaw meet. The TMJ moves during talking, yawning, chewing and swallowing. It is one of the most frequently used joints in the body. Proper functioning of the TMJ includes the use of several muscles, ligaments and bones. The temporomandibular joint enables the jaw to move and function normally. Any conditions that prevent these components from working properly may cause a TMJ disorder (TMD), which can cause pain and discomfort that can be intermittent or constant, and may last for many years. TMJ discomfort can sometimes flare up because of stress.
Causes of TMJ Disorders
The cause of temporomandibular joint disorders is not always apparent, but symptoms may develop from problems with the jaw muscles or with the joint itself. The causes of TMJ disorders may be related to the following:
- Trauma to the head or neck
- Oral habits such as clenching or grinding of the teeth
- "Bad" bite or missing teeth
- Malalignment of the upper and lower jaw
Types of TMJ Disorders
There are three main types of TMJ disorders. They include:
Internal Derangement of the Joint
A dislocated jaw, displaced TMJ disc or injury to the lower jaw can result in TMJ disorders. This is a structural, as opposed to muscular, symptom. It generally involves the progressive slipping or displacement of the articular disc within the temporomandibular joint.
Degenerative Joint Disease
The overuse or aging of the joint can cause degeneration and/or inflammation. This may be a result of osteoarthritis, rheumatoid arthritis or a perforated TMJ disc.
Myofascial Pain Disorder
When pain and discomfort occurs in the muscles surrounding the jaw joint, it can result in TMJ disorder. This pain may be the result of abnormal muscular function, daytime clenching or nocturnal grinding (bruxism).
A patient may experience one or more of these disorders at the same time.
Symptoms of TMJ Disorders
Symptoms of TMJ disorders may be constant or intermittent and may include:
- Chronic pain in the face, jaw, neck and shoulders and in or around the ear
- Limited ability to open the mouth wide
- Difficulty chewing
- Uncomfortable bite
- Swelling either on one or both sides of the face
- Clicking or popping noises when opening the mouth
- Headaches and neck aches
These conditions may cause symptoms that range from being barely noticeable to causing seriously debilitating pain. These symptoms are not all-inclusive for TMJ disorders and may be symptoms of other conditions as well. Therefore, it is important that the patient undergo a thorough examination by a qualified maxillofacial surgeon.
Diagnosis of TMJ Disorders
In order to diagnose a TMJ disorder, a doctor will review the patient's symptoms and perform a physical examination. The following tests may also be performed:
- Clench test
- CT scan or MRI scan
- Computer bite analysis
- Joint vibration analysis
Treatment for TMJ Disorders
Treatment for temporomandibular joint disorders may range from conservative dental/medical care to complex surgery. Short-term treatment may include pain medication, muscle relaxation, appliance therapy using a bite plate or splint, and, if necessary, stress-reduction counseling.
If nonsurgical treatment is unsuccessful or if there is joint damage, surgery may be needed. Types of surgery performed for TMJ disorders may include:
The surgeon cleanses the joint by inserting needles into the joint area and dispensing sterile fluid. Additionally, the surgeon may use a blunt instrument to remove any tissue adhesion bands and to reposition a disc that is stuck improperly in the joint hinge.
The surgeon uses an endoscope with a camera and light to visually inspect the joint. He or she may remove any adhesions, treat inflamed tissue or reposition the disc.
Open Joint Surgery
In more severe cases, open joint surgery may be performed to provide access to deteriorating bone, tumors or scarred bone. The surgeon may use a scalpel to remove or resculpt the affected area. Open joint surgery requires a longer healing time, and increases the chances of scarring or nerve damage.