(416) 538-8883
415 Bloor Street West Suite 300
Toronto, Ontario M5S 1X6

Causes of TMD

Causes of TMD

The temporomandibular joints are among the most utilized joints in the body, due to their prolonged use during chewing, talking, singing, yawning, etc. Jaw dysfunction (TM dysfunction) means that the lower jaw is not in its proper relationship to the upper jaw. This frequently results in a dislocation of the protective disc anteriorly as the lower jaw assumes a position further back than normal.

Some of the most common causes of TMD include:

  • Lower Jaw That is Too Far Back

    Contributing factors are but not limited to:

    • Deep dental overbite
    • Upper front teeth tipped backwards
    • Back teeth missing

    The temporomandibular joint is affected like no other joint in the body. Behind the condyle (top of lower jaw), there are several structures that affect the health of the jaw joint itself. One is the posterior ligament which acts as a rubber band to pull the disc backward during closing of the jaw.

    Like all joints, the TM joints contain a large amount of nerves and blood vessels that on a subconscious level give the brain information about the position and condition of the joint. When the jaw is closed, the disc, which has no feeling, acts as a shock absorber to prevent the nerves and blood vessels from being compressed. When the mouth opens and the condyle and the disc move forward, the blood vessels expand to fill the vacated space. When the condyle is pushed too far backwards in the joint, it can slip off the cartilage disc and into these nerves and blood vessels.

    When nerves and blood vessels are compressed, the whole structure is unbalanced, affecting the nerves, the ligaments and the muscles of the head, neck and face.

    This dislocated jaw causes pain and other symptoms, which affect health and a person's quality of life.

  • Unbalanced Muscles

    Unbalanced muscles can be a result of clenching or grinding of the teeth and/or bad posture. If a muscle is overworked or becomes fatigued due to a structural imbalance, other muscles must compensate. This compensation causes the body to adjust to an abnormal postural state.

    Compensation means the body adapts to a state that is unhealthy. The body will start to experience symptoms on a mild level, such as occasional headaches. Slowly the symptoms start to occur on a more frequent level until eventually you are experiencing pain on a daily basis.

    Whether you have a slightly displaced disc, a dislocated disc, unfavorable head posture or body posture, the abnormal forces and strain produced by tired, spastic muscles can refer pain into the neck, face or head. These muscle tension headaches can be so severe that they are confused with migraine headaches.

    Unfortunately, patients are often not examined for TMJ disorder and the 'migraine' treatment works poorly. The treatment for patients with migraine headaches is often the prescribing of pain medications such as Imitrex. This medication is ineffective in solving problems relating to dislocated jaw joints (TM dysfunction).

    Patients are advised to contact a dentist who utilizes appliances designed to reposition the lower jaw forward or to control parafunctional habits to try and solve the problem as early as it is diagnosed.

    An overwhelming majority of patients who sustain whiplash injuries in motor vehicle accidents (MVA) also dislocated one or both temporomandibular joints at the same time without having impacted their face or head against the steering wheel, door column, windshield or other parts of the car. Whiplash typically occurs if the head is thrown backward and forward while riding in a car that is hit from behind or the side. Extensive research has well documented the fact that most flexion-extension injuries occur following what is called "minor head injuries."

    This means that it is not necessary to suffer a fracture or even a direct head impact. In fact, most patients report that their head was simply snapped backward and forward or side to side. This motion causes damage to the muscles and ligaments which support the jaw joint. When these muscles and ligaments are injured, this can cause an anterior displacement of the protective disc and result in a dislocated jaw joint on one or both sides.

  • Trauma From a Blow to the Head or Jaw

    Trauma from a blow to the head or jaw including automobile accidents, whiplash or intubation procedures in hospitals. A severe blow the head or the jaw can cause the disc to be dislocated due to the force of the impact on the jaw. Patients may experience swelling, limited opening and clicking in the joint.

    Patients with this acute injury should seek emergency treatment immediately to avoid further damage to the joint.

  • Orthodontics and/or Bad Bite (Malocclusion)
  • Opening the Jaw Too Wide
  • Ligament Laxity
  • Stress
  • Systematic Disease

Food and drinks known to aggravate headaches for some patients include:

Soft drinks
M.S.G. Flavor enhancer user to preserve foods Artificial Sweeteners Aspartame
Vegetable Oil Fried or greasy foods should be avoided
Milk and Cheese
Raw Beans

© Bloor Dental Health Centre - All Rights Reserved