FAQs

Trauma.

According to statistics published in the Journal of the American Dental Association in 1990,* 44% to 99% of TMJ problems are caused by trauma. 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 with direct trauma to the head or jaw. (* JADA 1990;120:267)

Cervical Acceleration/Deceleration ( Whiplash ).

When one is riding in a vehicle and is struck by another vehicle, often soft tissue injuries in the neck, back, and TMJs may occur. Although the injury may occur from any direction, usually it comes from the rear.When a Cervical Acceleration/Deceleration (CAD) or Whiplash injury is produced, the head is thrust in the direction of the impact. For example, when sitting at a traffic light and a car is struck from the rear by another car, the heads of the occupants in the first vehicle are thrust backwards towards the rear. As the head is thrown backwards, inertia (remember Newton’s Law that a body at rest tends to stay at rest until acted upon by an outside force?) causes the lower jaw or mandible to remain where it was in space for about 250 milliseconds (about 1/4 of a second). This violent motion, causing the head to be thrown backwards also causes anterior mandibular displacement as the mouth is forced open. Notice: just opposite as it might seem, initially during a rear-end whiplash injury, the rearward or posterior thrust of the head causes anterior instead of posterior TMJ injury. This produces stretching and/or tearing of the ligaments and connective tissues in one or both TMJs, bleeding, and often, displacement of the articular disc in the TMJ.

At the moment of impact from the rear, as the head is thrust backwards, the vehicle is actually accelerated forward as the body of the occupant moves backward, thus forcing him or her into the seat. As the mouth is thrown open, producing TMJ injury, the head either hits the head rest or extends over the headrest.

Then, as the vehicle comes to rest, the occupant is still moving forward until he or she is stopped either by a lap belt and shoulder harness, or, the steering wheel or windshield. During this last movement, the head is thrust forward while inertia causes the mandible to be thrust suddenly backward, traumatically closing the mouth violently. This motion may fracture or chip teeth and further injure the posterior part of the TMJ. Note: with the development of all the above injuries, no direct trauma to the head or jaw has yet occurred, demonstrating that direct trauma IS NOT NECESSARY for a whiplash injury to severely damage the TMJs and teeth.

• Common complaints following a CAD or Whiplash injury may include:
• Neck pain
• Neck stiffness (difficulty in turning the head)
• Headaches (especially, temporal and occipital –where neck attaches to head)
• Back pain
• TMJ symptoms (joint pain, limited opening of the mouth, change in bite, TMJ noises, pain in face and TMJs with mouth opening, ear pain)
• Dizziness
• Visual changes (light sensitivity, blurred vision, etc.)
• Swallowing difficulties and even hoarseness

Air Bag Deployment.

Direct trauma to the mandible in auto accidents, like indirect trauma in whiplash injuries, are both known to produce TMJ injuries. Recently, however, the advent of air bags, which no doubt have saved numerous lives, has been implicated in causing TMJ problems.Personally, I’ve seen several patients in the last couple of years who have been hit only with air bags which deployed when the car was impacted in an accident. Patients who’ve been injured with air bags often have the following symptoms:

• Burned or abraded skin on the chin, face and even the nose
• Almost immediate TMJ pain
• Swelling of the TMJs
• Limited mouth opening
• Lateral and cervical neck pain
• Change in the dental occlusion (bite)

Opening Too Wide

All joints have limitations to movement and the TMJ is no exception. If you open wide for a long time, or if your mouth is forced wide open, ligaments again may be torn. Swelling and bruising develop and disc dislocation may occur. For example, if your mouth is open for a long time at the dental office while having a tooth prepared for a crown, the joint can dislocate. This rarely happens without a prior history of trauma; however, it does happen. Also, this type of injury may occur if someone’s mouth is opened too wide when they are being put to sleep for surgery. Again, both of these examples are accidental and consequences of the given procedures.

PERPETUATING FACTORS

Bruxism

Bruxism is the abnormal grinding of the teeth. If grinding continues, TMJ may develop. Bruxism usually occurs during sleep. That is why so many people do not realize that they are bruxers. One indication that a person is a bruxer is sore jaw muscles when waking in the morning. Some researchers feel that the constant grinding of the teeth causing pressure on the TMJs may injure the ligaments, thus allowing for the disc to dislocate. At the very least, bruxism produces muscle pain, sensitive and worn teeth.

Malocclusion

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

Orthodontics

Some dentists feel that orthodontic treatment, or braces, might be a cause of TMJ. By moving teeth with orthodontic appliances, malocclusion is produced during treatment. Also, people undergoing orthodontics do report sensitive teeth, pain in the jaw muscles and even bruxism. However, as with malocclusion, there has been no scientific controlled study to prove that orthodontic treatment produces a TMJ problem.

Ligament Laxity

People who appear to be double-jointed actually suffer from a problem termed a ligament laxity. If this occurs, then the joint appears to be double or, loose. This definitely can happen to the TMJ’s. Ligament laxity is a fairly common problem in active young women who suffer with TMJ (and injuries to other joints).

Stress

Stress has many effects on our bodies: some good and some bad. Stress, being both physical and psychological. Physiological changes can produce muscle tightness and pain and if you are subjected to chronic stress, these physical changes may produce harmful effects. For example, people subjected to chronic stress develop ulcers, diarrhea, tension headaches, muscle tightness and other physical symptoms. Stress is just like throwing gasoline on an existing fire: the fire is a TMJ problem and the gasoline is stress. The gasoline causes the fire to flair up and burn widely for a time, but the gas did not produce the fire (or, TMJ), it just made it worse. This is how it appears that stress acts in conjunction with a TMJ problem. 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, then 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. In addition, viral infections such as mononucleosis, mumps and measles can cause damage to the surfaces of the TMJ, which ultimately can lead to an internal derangement.

TEMPORAL TENDONITIS.

Temporal tendonitis has been called “The Migraine Mimic” because so many symptoms are similar to migraine headache pain. Symptoms include: TMJ pain, ear pain and pressure, temporal headaches, cheek pain, tooth sensitivity, neck and shoulder pain. Treatment consists of injecting local anesthetics and other medications, a soft diet, using moist heat, muscle relaxants and anti-inflammatory medications, and physiotherapy. Only rarely (in approximately 4% of cases) is surgery needed.

ERNEST SYNDROME.

This TMJ-like problem involves the stylomandibular ligament, at tiny structure that connects the base of the skull with the mandibular, or lower jaw. If injured, this structure can produce pain in as many as seven specific regions of the face, head and neck: the temple, the TMJ, the ear, the cheek, the eye; the throat, especially when swallowing, and the lower back teeth and jaw bone. Treatment of Ernest syndrome, which is successful about 80% of the time, consists of injections of local anesthetic and medication (cortisone or Sarapin), physiotherapy, and at times, the use of an intraoral splint.

OCCIPITAL NEURALGIA

Occipital neuralgia is generally ignored in the medical textbooks. This disorder is characterized by pain located in the cervical and posterior regions of the head (these are the occipital areas) which may or may not extend or radiate into the sides of the head and ultimately, into the facial and frontal regions. There are actually two major types of occipital neuralgia: lesser occipital and greater occipital, with the lesser type being more common.

TRIGEMINAL NEURALGIA

Trigeminal neuralgia is a terrible disorder of the trigeminal, or fifth cranial nerve. This is one of the most painful problems that plagues human beings. In fact, its description first appeared in the scientific literature in 1672. Another common name for trigeminal neuralgia is tic douloureux which literally means unbearably painful twitch . Far too often, when a person is suffering with severe facial pain with no apparent cause, the diagnosis given is trigeminal neuralgia. Because of this, the patient may be subjected to medications and even very serious surgical procedures which are not necessary. The symptoms of tic douloureux are very characteristic: sharp electrical pain which lasts for seconds. This pain is triggered by touching a specific area of the skin by washing, shaving, applying makeup, brushing the teeth, kissing, or even cold air. The second division of the trigeminal nerve (the maxillary division), which supplies feeling to the mid-face, upper teeth and palate, seems to involved most. The pain is so severe that the sufferer will do virtually anything to avoid touching the trigger zone, producing the pain.

ATYPICAL TRIGEMINAL NEURALGIA

In contrast to the typical type, atypical trigeminal neuralgia seems to cause pain constantly with the intensity increasing and decreasing. There are trigger zones with this type; however, there also is an area of dull aching which is intensified by touching the trigger zones. All three divisions of the trigeminal nerve seems to be affected equally. A common cause of this disorder is trauma, especially after a surgical incision or blow to the face.

ATYPICAL FACIAL PAIN

Atypical facial pain is a disorder that also affects the trigeminal nerve. However, the symptoms are not clearly defined as they are in typical and atypical trigeminal neuralgia. Atypical facial pain seems to affect people who are under a tremendous amount of stress and may even have a history of psychiatric problems. This does not mean that one suffering with atypical facial pain is mentally ill. We who treat this problem need to do much more research to understand this terrible disorder.

Neuralgia Inducing Cavitational Osteonecrosis (NICO)

As recent as 1979, a newly described pain disorder was reported. This disorder, which came to be known as osteocavitational lesions (Ratner’s bone cavities,) produced pain similar to trigeminal neuralgia, both the typical and atypical types. In fact, usually these patients were diagnosed with trigeminal neuralgia. The diagnosis is complicated by the fact that the x-ray examination of the bone is usually normal. Also, NICO produces referred pain patterns which also serve to confuse both patient and doctor. However, just like trigeminal neuralgia, there are trigger areas that, when pressed, produce pain. These trigger areas develop directly over the areas of dead bone. The mandible is affected more often than the upper jaw. One important aspect of NICO is a history of tooth extraction usually years earlier. Any tooth may be involved. However, lower back teeth seem to be most common. Small areas of bone actually die, producing neuralgia-like pain symptoms. It appears that after a tooth extraction, NICO may develop due to injury of the blood vessels in the area which ultimately results in poor circulation, resulting in bone death in some cases. Pathologically, this is termed osteomyelitis. This bone infection, which can result in bone death, has been known for years. Yet, in the form of NICO, it is a newly described problem.