Causes of TMJ

Statistics indicate that the vast majority of TMJ problems are caused by trauma. There are two types of trauma; Macro-trauma where there is a physical injury such as a car accident By trauma, we mean an injury as obvious as a blow to the jaw with a fist or something as subtle as a whiplash injury from a car accident that causes direct trauma to the head or jaw.

The other form is micro-trauma. This is when the relationships between the joint and the bite as well as other bones in the skull are not correct and the joint is subject to excessive loads and is damaged in small amounts but in  a never-ending manner.

The most common forms of trauma that cause TMD are:

•     Opening the jaw too wide
•     Bruxism
•     Bad bite (malocclusion)
•     Ligament laxity
•     Stress
•     Systemic diseases – Mumps, Measles or Lupus

Opening the Jaw Too Wide

Opening wide such as yawning, long dental appointments or even biting an apple!

All joints have limitations in movement, and the TMJ is no exception. If you open wide for a long time or if your mouth is forced wide open, ligaments may be torn, swelling and bruising develop and disc dislocation may occur.

Bruxism

Waking with a headache in the Temples. That is on the side of your head.

Bruxism is the abnormal grinding of the teeth. Bruxism usually occurs during sleep, which is why many people don’t realize they are doing it. But when grinding continues, TMJ problems may develop. An indication that a person is grinding their teeth in their sleep is sore jaw muscles when waking. Minimally, bruxism may produce muscle pain, tooth sensitivity or worn teeth. In some cases, the pressure to the TMJ from constant grinding of teeth leads to ligament injuries, which might cause the disc to dislocate.

Bad Bite (Malocclusion)

A bad bite, or malocclusion, may be produced by poor development of the jaws, removal of teeth without replacement, a high dental restoration, a poorly fitting denture or partial denture, or a displaced TMJ disc.

Ligament Laxity

People who appear to be double-jointed suffer from a problem termed ligament laxity. When this occurs, a joint appears to be double – or loose. This does happen to the TMJ. Ligament laxity is a fairly common problem in active young women who suffer with TMJ problems and, often injuries to other joints.

Stress

Stress has many effects on our bodies: some good and some bad. Physiological changes can produce muscle tightness and pain. When a person is subjected to chronic stress, these physical changes may produce harmful effects. When it comes to TMJ problems, stress is like throwing gasoline on a fire. The gasoline doesn’t produce the fire, but it does make it worse. Similarly stress intensifies TMJ problems. Muscles tighten, teeth clench, abnormal pressure is forced against the TMJ disc, and if the ligaments are weak or if the patient is one that has ligament laxity, the disc may dislocate.

Systemic Diseases

Various diseases can cause or aggravate TMJ problems. Immune disorders, such as rheumatoid arthritis, psoriatic arthritis and systemic lupus erythematosus, can produce inflammation in the TMJ. Additionally, viral infections, such as mononucleosis, mumps and measles, can cause damage to the surfaces of the TMJ, which can lead to an internal derangement.

There are a number of other pain disorders that are often confused with TMJ because they involve pain in the jaw. Most common among these are:

•     Temporal Tendinitis
•     Occipital Neuralgia
•     Trigeminal Neuralgia

Temporal Tendinitis – The “Migraine Mimic”

Temporal tendinitis has been called “the migraine mimic” because so many of its symptoms are similar to migraine headache pain.  It is characterized by TMJ pain, ear pain and pressure, temporal headaches, cheek pain, tooth sensitivity and neck and shoulder pain. Treatment consists of injecting local anaesthetics and other medications, a soft diet, applying moist heat, using muscle relaxants and anti-inflammatory medications, and physiotherapy. In very rare cases (less than 4%), surgery may be needed.

Occipital Neuralgia

This disorder is characterized by pain radiating to one or both sides of the head, temples, cheek and forehead and particularly pain above and behind the eye.

Trigeminal Neuralgia

Also known as tic douloureux, this is a disorder of the trigeminal, or fifth cranial nerve. It is characterized by sharp electrical pain, which lasts for seconds. The pain is triggered by touching a specific area of the skin, as when washing, shaving, applying make-up, brushing the teeth, kissing or even from exposure to cold air. The pain is often very severe.