Symptoms vary in their presentation and can be very complex. Oftentimes the symptoms will involve more than one of the three components: muscles, the joints, and the teeth.
Disorders of the muscles of the temporomandibular joint are the most common complaints by patients. The two major observations concerning the muscles are pain and dysfunction. Simple cases of this type are caused by over usage of the muscles commonly caused by chewing gum continuously, biting habits (fingernails and pencils), grinding habits and clenching habits. Other cases are not that simple. Muscles can also be damaged more insidiously by infection, trauma (past or present), bruising and scarring – just to name a few. In less common cases, muscle inflammation can sometimes be associated with trigger points in muscle tissue. This is known as Myofascial pain syndrome.
Any dysfunction of the muscles may cause the teeth to occlude (bite) with each other incorrectly. If teeth are traumatized by this occlusion, they may become sensitive demonstrating one of the many interplays between muscles, joints and teeth.
This is arguably the most complex set of joints in the human body. Unlike typical finger or vertebral junctions, these joints actually have two joints which allow them to both rotate and to translate (slide). It is common to see wear of both the bone and cartilage components of these joints.
Clicking is a common complaint, as are popping and deviations in the movements of the joint. It is considered a TMJ disorder when pain is involved.
In a healthy joint, the surfaces in contact with one another (bone and cartilage) do not have any receptors to transmit the feeling of soreness. It usually originates from one of the surrounding soft tissues. When receptors from one of these areas are triggered, the pain causes a reflex to limit the mandible’s movement. Furthermore, inflammation of the joints can cause constant pain, even without movement of the jaw.
Due to close proximity of the ear to the temporomandibular joint disorder, it can be confused as ear pain. It may be referred in or around the ear region and manifest itself as ringing, itchiness or stuffines in the ears.
The dysfunction involved is most often in regard to the relationship between the condyle of the mandible and the disc. The sound produced by this dysfunction is usually described as a “click” or a “pop” when a single sound is heard. When there are multiple, rough sounds, it is described as “crepitation” or “crepitus“.
Disorders of the teeth can also be present. Tooth mobility can be caused by destruction of the supporting bone and by heavy forces being placed on teeth. Movement of the jaw affects how the teeth contact one another when the mouth closes. The overall relationship between the teeth, muscles, and joints can be altered. The heavy forces on the teeth have been associated with the presence of mandibular tori (bony bumps under the tongue) in TMJ patients. Pulpitis, inflammation of the dental pulp, is another symptom that may result. Heavy grinding forces on the teeth can cause pain and excessive wear. Tooth wear (bruxism) is a most common finding.
There are many external factors that place undue strain on the area. These include but are not limited to the following:
Over-opening the mouth beyond its range unusually aggressive or repetitive movement sliding sideways (laterally) or forward (protrusivley). May be due to wayward habits or a malalignment or dentition. This may be due to alterations in the surfaces and position of teeth due to dental treatment such as braces, caps/crowns, bridges, partial dentures, or extractions due to oral surgery.
Other surgeries the patient may have had during their life, such as medical or cosmetic proceduresrequiring general sedation and anaesthesia, can also be contributing factors leading to a jaw/joint disorder.
Even past sporting injuries can lead to jaw/joint instability and pain. In Dr. DiVito’s experience, including several thousand patients, the most common cause of jaw joint, head, neck facial pain is trauma. A very common form of trauma is that found as a result of motor vehicle accident injury. This often involves whiplash.
Whiplash is an injury to the jaw caused by an abrupt jerking motion of the head in the course of an accident that causes dislocation and damage to the soft jaw tissue structures. The term whiplash dates to the days when buggy whips were commonly used and refers to the rapid motion of the thin tip of the whip that causes a loud crack when the direction of the tip changes rapidly.
In the neck trauma victim, the neck, head and jaw are the whip. The violent change in direction and velocity that causes the whip to crack, can cause a permanent injury to ligaments and discs from which the victim may never fully recover without treatment. One way these injuries occur is when the victim is in a motor vehicle sitting at a red light and is hit from behind, causing a rapid acceleration of the vehicle and the victim’s body. This violent wrenching can equal the energy of a fall from a two story building in even a seemingly minor accident. Other injuries such as falls, sports injuries and head trauma are also commonly associated with very severe problems.
These can create major hard and soft tissue damage to the patient who is not aware of the pending impact. The head rapidly snapping back and forth can cause multiple soft tissue injuries that are hard to find on x-rays and even more difficult to treat. In many cases, long term therapy to obtain the best remission of symptoms will be necessary.