TMJ (Temporo Mandibular Joint) – How and Why
Pain and the TMJ, What is the TMJ?
The Temporo-Mandibular Joint (TMJ) is the joint where the mandible (the lower jaw) joins the temporal bone of the skull, immediately in front of the ear on each side of your head. A small disc of cartilage separates the bones, as like in the knee joint, so that the mandible may slide easily; every time during chewing it moves. It moves every time we talk and each time we swallow (every three minutes or so). It is, therefore, one of the most frequently used of all joints of the body.
The joint can be located by putting the finger on the triangular structure in front of the ear. Then move the finger just slightly forward and press firmly while opening your jaw all the way and shut it. The motion we feel is the TMJ. We can also feel the joint motion in the ear canal.
These maneuvers cause discomfort to a patient who is having TMJ problems, and physicians use these maneuvers with patients for diagnosis. As the nerve supply of the joint, ear and head area are the same, pain in the joint is felt as pain in the ear and above it.
How does the TMJ work?
When we bite down hard, the force acts on the object between the teeth and the joint. In terms of physics, the jaw is the lever and the TMJ is the fulcrum and more force is applied (per square foot) to the joint surface than to whatever is between the teeth. To accommodate such forces and to prevent too much wear and tear, the cartilage between the mandible and skull normally provides a smooth surface, over which the joint can freely slide with minimal friction.
The forces of chewing can be distributed over a wider surface in the joint space and minimize the risk of injury. In addition, several muscles contribute to opening and closing the jaw and aid in the function of the TMJ.
- Pain in the ear
- Sore jaw muscles
- Temple/cheek pain
- Jaw popping/clicking
- Jaw dislocation
- Difficulty in opening the mouth fully
- Frequent head/neck aches
How does TMJ dysfunction feel?
The pain may be severe and searing, occurring each time we swallow, yawn, talk, or chew, or it may be dull and constant. It hurts the joint, immediately in front of the ear, but pain can also radiate elsewhere. It causes spasms in the adjacent muscles that are attached to the bones of the skull, face, and jaws. Pain can be felt at the side of the head, the ear, the cheek, the lower jaw, and the teeth.
A very common focus of pain is in the ear. Many patients come to the ear specialist quite convinced that the pain is from an ear infection. When the earache is not associated with a hearing loss and the eardrum looks normal, the doctor will consider the possibility that the pain comes from a TMJ dysfunction.
The other symptoms that TMJ dysfunction can cause.
- popping, clicking, or grinding sounds when the jaws are opened widely.
- The jaw gets dislocated, TMJ dysfunction can prevent the jaws from fully opening.
- Some patient get ringing in their ears from TMJ trouble.
How can things go wrong with the TMJ?
In most cases, pain associated with the TMJ is a result of displacement of the cartilage disc that causes pressure and stretching of the associated sensory nerves. The popping or clicking occurs when the disk snaps into place when the jaw moves. In addition, the chewing muscles may spasm, not function efficiently, and cause pain and tenderness.
Both major and minor trauma to the jaw can significantly contribute to the development of TMJ problems. If we clench, grit, or grind the teeth, the wear on the cartilage lining of the joint increses and recovery gets prolonged, and it doesn’t have a chance to recover. Many are unaware that they grind their teeth, unless someone tells them so.
Chewing gum much of the day can cause similar problems. Stress and other psychological factors have also been implicated as contributory factors to TMJ dysfunction. Other causes include teeth that do not fit together properly (improper bite), mal positioned jaws, and arthritis. In certain cases, chronic mal position of the cartilage disc and persistent wear in the cartilage lining of the joint space can cause further damage.
What can be done?
Because TMJ symptoms often develop in the head and neck, otolaryngologists are appropriately qualified to diagnose TMJ problems. Proper diagnosis of TMJ begins with a detailed history and physical examination, including careful assessment of the teeth occlusion and function of the jaw joints and muscles. If the doctor diagnoses your case early, it will probably respond to these simple, self-remedies:
Rest the muscles and joints by eating soft foods.
Do not chew gum.
Avoid clenching or tensing.
Relax muscles with moist heat (1/2 hour at least twice daily).
In cases of joint injury, ice packs applied soon after the injury can help reduce swelling. Relaxation techniques and stress reduction, patient education, non-steroidal anti-inflammatory drugs, muscle relaxants or other medications may be indicated as your doctor recommends.
Other therapies may include fabrication of an occlusal splint to prevent wear and tear on the joint. Improving the alignment of the upper and lower teeth and surgical options are available for advanced cases. After diagnosis, your otolaryngologist may suggest further consultation with your dentist and oral surgeon to facilitate effective management of TMJ dysfunction.