Temporomandibular Disorders (TMD)
Temporomandibular disorders (TMD) happen as a result of problems with the jaw, jaw joint, and surrounding facial muscles that control chewing and moving the jaw. These disorders are often incorrectly called TMJ, for temporomandibular joint.
What Is the Temporomandibular Joint?
The temporomandibular joint is the hinge joint that connects the lower jaw (mandible) to the temporal bone of the skull, which is immediately in front of the ear on each side of your head. The joints are flexible, allowing the jaw to move smoothly up and down and side to side and enabling you to talk, chew, and yawn. Muscles attached to and surrounding the jaw joint control the position and movement of the jaw.
What Causes TMD?
The cause of TMD is not clear, but dentists believe that symptoms arise from problems with the muscles of the jaw or with the parts of the joint itself.
Injury to the jaw, temporomandibular joint, or muscles of the head and neck -- such as from a heavy blow or whiplash -- can cause TMD. Other possible causes include:
- Grinding or clenching the teeth, which puts a lot of pressure on the TMJ
- Dislocation of the soft cushion or disc between the ball and socket
- Presence of osteoarthritis or rheumatoid arthritis in the TMJ
- Stress, which can cause a person to tighten facial and jaw muscles or clench the teeth
What Are the Symptoms of TMD?
People with TMD can have severe pain and discomfort that can be temporary or last for many years. More women than men experience TMD and TMD is seen most commonly in people between the ages of 20 and 40.
Common symptoms of TMD include:
- Pain or tenderness in the face, jaw joint area, neck and shoulders, and in or around the ear when you chew, speak, or open your mouth wide
- Limited ability to open the mouth very wide
- Jaws that get "stuck" or "lock" in the open- or closed-mouth position
- Clicking, popping, or grating sounds in the jaw joint when opening or closing the mouth (which may or may not be accompanied by pain)
- A tired feeling in the face
- Difficulty chewing or a sudden uncomfortable bite -- as if the upper and lower teeth are not fitting together properly
- Swelling on the side of the face
Other common symptoms of TMD include toothaches, headaches, neckaches, dizziness, earaches, and hearing problems.
How Is TMD Diagnosed?
Because many other conditions can cause similar symptoms -- including a toothache, sinus problems, arthritis, or gum disease -- your dentist will conduct a careful patient history and physical exam to determine the cause of your TMD symptoms.
He or she will examine the temporomandibular joints for pain or tenderness; listen for clicking, popping, or grating sounds during jaw movement; look for limited motion or locking of the jaw while opening or closing the mouth; and examine bite and facial muscle function. Sometimes panoramic X-rays will be taken. These full-face X-rays allow your dentist to view the entire jaw, TMJ, and teeth to make sure other problems aren't causing the symptoms. Sometimes other imaging tests, such as magnetic resonance imaging (MRI) or a computer tomography (CT), are needed. The MRI views the soft tissue, such as the TMJ disc, to see if it is in the proper position as the jaw moves. A CT scan helps view the bony detail of the joint.
Your dentist may decide to send you to an oral surgeon (also called a maxillofacial surgeon) for further care and treatment. This type of doctor specializes in surgical procedures in and about the entire face, mouth, and jaw area.