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Temporomandibular Joint Disorder

Temporomandibular Joint Disorder: What is It

Temporomandibular Joint Disorder (TMD) is a group of conditions that cause pain and loss of normal function to the temporomandibular joint (TMJ) or jaw joint. The temporomandibular joint is located in front of the ear, on both sides of the head.

The joint is made up of the lower jawbone and the skull. A cartilage disk, which functions as a shock absorber and joint lubricant, separates these two bones. The TMJ and the muscles of chewing enable you to open your mouth, talk and chew.

TMD can originate from the chewing muscles, cartilage disk or the joint bone.

Temporomandibular Joint Positions

Normal Closed Position
The lower jawbone is separated from the skull by a cartilage disk that acts as a cushion when the joint is in function i.e. chewing, speaking and yawning.

TMJ normal closed position - National Dental Centre Singapore

Normal Open Position
On the opening of the mouth, the disk will follow the lower jaw bone and they will move together when you move your jaw up and down or side to side.

TMJ normal open position - National Dental Centre Singapore

In an abnormal joint, the disk can be displaced or torn. This displaced or torn disk can cause obstruction in joint movement. A torn disk can result in excessive wear of the bone of the joint, causing inflammation and pain.

TMJ abnormal position - National Dental Centre Singapore

Causes of Temporomandibular Joint Disorder

Causes of TMD can be caused by:

  • Prolonged stress to the jaw joint. Habitual clenching or grinding of your teeth overloads the joint, causing pain in the joint and muscles. You may not be aware of these habits if they occur during sleep.
  • Trauma. A recent trauma or a history of trauma, such as a blow to the lower jaw or face, whether directly or indirectly, can injure the TMJ.
  • Arthritis. The jaw joint may be damaged by arthritis (inflammation of the joint). Arthritis may be a degenerative process due to ageing or it may be associated with medical conditions such as Rheumatoid Arthritis and Psoriatic Arthritis.

Signs and Symptoms of Temporomandibular Joint Disorder

  • Noises. You may hear clicking or grating noises on opening or closing your mouth. If this is not accompanied by pain and limitation in mouth opening, no treatment is required.
  • Pain. Dull pain, on opening and closing of the mouth, can be experienced over the jaw joint area (just in front of the ear) or at the cheek or at the temple region. A clicking or grating sound may accompany the pain. The pain is usually due to inflammation of the joint and/or the muscles, and may cause difficulty in chewing and biting food. Sometimes you may experience headaches.
  • Restriction in mouth opening and closing. Trauma, excessive pressure or degenerative changes to the joint can cause displacement of the cartilage disk in the joint. This causes obstruction to the normal movement of the joint, leading to difficulty in opening and closing your mouth.
  • Worn-down, cracked and fractured teeth. Teeth may be worn down as a result of nocturnal grinding and you may experience teeth sensitivity. Teeth may also be cracked and fractured as a result of nocturnal grinding and clenching. This leads to pain and difficulties in chewing.

You may experience difficulty in eating and a sudden inability to close your mouth, which may or may not be spontaneously resolved.

Signs of temporomandibular joint disorder - National Dental Centre Singapore

Diagnosis of of Temporomandibular Joint Disorder

Seek a consultation with your dentist. Most common issues are related to the masticatory muscles. Jaw disk displacements are also commonly encountered. Arthritis changes jaw joints which can also cause jaw discomfort.

A routine X-ray scan of the upper and lower jaw helps to rule out obvious bony lesions. Sometimes, more complicated imaging may be necessary.

Treatment for Temporomandibular Joint Disorder

TMD may be treated surgically or nonsurgically, depending on the diagnosis and the cause.

1. Medications. Some antiinflammation drugs can be helpful in reducing the pain associated with TMD.

2. Therapies. Some TMD symptoms can be relieved with the use of a bite guard. A bite guard is especially useful for patients who grind their teeth during sleep.

Treatment for Temporomandibular Joint Disorder - bite guard - National Dental Centre Singapore

3. Surgery. Surgery may be one option for patients who do not respond well to non-surgical treatment. Surgery may range from simple washing of the joint with fluids (arthrocentesis) to inserting a small scope into the joint to examine and treat the joint (arthroscopy).

4. Restoring natural teeth. Worn-down teeth may need to be crowned.

5. Counselling and stress management.

Prevention of Temporomandibular Joint Disorder

  • Strive for a balanced lifestyle.
    Stressful episodes predispose one to more grinding and clenching of the teeth.
  • Excessive chewing on hard foods.
  • Seek help when you encounter the signs and symptoms and TMD.