Temporomandibular Disorders (TMD)

Temporomandibular disorders (TMD) can result from a single cause or, more commonly, a combination of causes.

The main causes of TMDs include:

• Muscle tension (tightness) and spasm. Muscle tension in the jaw, face, head, neck, and shoulders may make your jaw feel achy, stiff, and painful, especially when moving your jaw. Muscle tension may be:
  • Caused by stress and anxiety and by stress-related habits, such as daytime or nighttime clenching or grinding of your teeth (Reference bruxism), excessive gum chewing, or nail biting.
  • A response to Reference injury or structural problems within the joint.
• Problems in the internal structure of the joint, such as:
  • Reference Displacement of the disc that cushions the joint.
  • Degenerative disease, such as osteoarthritis or rheumatoid arthritis, which causes inflammation and destruction of the joint tissues.
  • Scar tissue or bone damage caused by accidental injury or a blow to the jaw.
  • Disease, such as a tumor, or structural problems present at birth (congenital).

In many cases, TMD symptoms appear to be caused by both muscle tension (tightness) and joint dysfunction. It is not always clear which came first. For example, osteoarthritis can cause changes in the joint, which may then bring on muscle spasms. Conversely, muscle spasms over time hinder jaw function and can eventually cause osteoarthritis in the jaw joint. A similar relationship appears to exist between muscle tension and disc displacement within the joint.

Reference Orthodontic treatment Opens New Window and Reference malocclusion Opens New Window do not seem to trigger TMDs or make them worse.

When jaw joint problems are caused by diseases such as rheumatoid arthritis, treatment for that condition is important. Many other conditions cause symptoms similar to those of TMDs, such as migraine headaches and infections.

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