Temporomandibular disorders (TMD) occur 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, which stands for temporomandibular joint.
What Is the Temporomandibular Joint (TMJ)?
The temporomandibular joint (TMJ) 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 experience 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) or chewing
- 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
- May occur on one or both sides of the face
- Other common symptoms include toothaches, headaches, neck aches, dizziness, earaches, hearing problems, shoulder pain, and ringing in the ears (tinnitis).
How Is TMD Diagnosed?
Because many other conditions can cause similar symptoms to TMD – including a toothache, sinus problems, arthritis, or gum disease – your dentist will conduct a careful patient history and physical examination to determine the cause of your symptoms.
Your dentist will examine your 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 jaws, temporomandibular joint, and teeth to make sure other problems aren’t causing the TMD 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 for further care and treatment.
Surgery for TMD
There are three types of surgery for TMD: Arthrocentesis, Arthroscopy, and Open-Joint Surgery. The type of surgery needed depends on the TMD problem.
Arthrocentesis: This is a minor procedure performed in the office under general anesthesia. It is performed for sudden-onset, closed lock cases (restricted jaw opening) in patients with no significant prior history of TMJ problems. The surgery involves inserting needles inside the affected joint and washing out the joint with sterile fluids. Occasionally, the procedure may involve inserting a blunt instrument inside of the joint. The instrument is used in a sweeping motion to remove tissue adhesion bands and to dislodge a disc that is stuck in front of the condyle (the part of your TMJ consisting of the “ball” portion of the “ball and socket”)
Arthroscopy: Patients undergoing arthroscopic surgery for TMD first are given general anesthesia. The surgeon then makes a small incision in front of the ear and inserts a small, thin instrument that contains a lens and light. This instrument is hooked up to a video screen, allowing the surgeon to examine the TMJ and surrounding area. Depending on the cause of the TMD, the surgeon may remove inflamed tissue or realign the disc or condyle. Compared with open surgery, this surgery is less invasive, leaves less scarring, and is associated with minimal complications and a shorter recovery time. Depending on the cause of the TMD, arthroscopy may not be possible, and open-joint surgery may be necessary.
Open-Joint Surgery: Patients undergoing open-joint surgery also are first given general anesthesia.Unlike arthroscopy, the entire area around the TMJ is opened so that the surgeon can get a full view and better access. There are many types of open-joint surgeries. This treatment may be necessary if:
- The bony structures that comprise the jaw joint are deteriorating
- There are tumors in or around your TMJ
- There is severe scarring or chips of bone in the joint