• The temperomandibular joint
• The muscles of mastication (chewing)
• The teeth
  

Unfortunately, with TMD, one or all of the components can become impaired if the system is stressed. Stress, be it physical, psychological, or emotional, can increase activity of the limbic system of the central nervous system. This is the center responsible for the "fight-or-flight" reaction we have when we are truly scared. Physical stress can come in the form of trauma or accidental injury (whiplash, assault, etc.). Emotional stress includes not only issues like divorce, death or other negatives of life, but also things such as weddings, babies, buying a new home, and other positives in life.

Unfortunately, activation of the limbic system can result in activation of a habit known as bruxism (grinding and clenching of the teeth). This magnifies any slight imperfection in the bite, resulting in either breakdown of the teeth, spasm of muscles in the jaw and/or breakdown of the jaw joint itself. Prolonged spasm of facial muscles can lead to chronic muscle pain, often perceived in other areas (referred pain) and thus subject to misdiagnosis.

Signs and Symptoms of TMD 
The difference between a sign and a symptom is that a symptom is what you can feel and a sign is what you and your dentist can see or hear. Often, people exhibits signs of TMD, such as breakdown of the components of the masticatory (chewing) system, but do not experience symptoms. Interestingly, 75% of patients complaining of symptoms are females. The reason for this is not fully understood, but some theorize that the larger number of estrogen receptors in females' musculature make women more aware of spasms.

TMD disorders can mimic many other disorders due to the nature of the syndrome. Many people have trouble getting a proper diagnosis. In many cases, the professional that should be consulted is not a medical doctor, but a dentist.

TMD symptoms may include any of the following:

• Congestion or ringing in the ears
• Clicking, popping or grating sounds when opening and closing the mouth
• Limited jaw opening or locking
• Difficulty closing the teeth together
• Neck pain or stiffness
• Tired jaws when chewing
• Dizziness
• Headaches, earaches and fainting
• Pain when chewing
• Facial pain
• Numbness in hands
• Difficulty in swallowing
  

Clenching and grinding of the teeth (bruxism) is probably the most common sign of TMD disorder. This can easily be diagnosed by your dentist when examining the wear on your teeth. Some epidemiologists have estimated that up to 60% of the population of Canada and the United States clench their teeth to some degree. Yet recent studies have indicated that over 85% of people do not know that they grind their teeth. Further, diagnosis of bruxism by a spouse or partner is missed even more often.

To make diagnosis even more difficult, most of our worst grinding happens when we are asleep. In fact, most people generate eight to ten times more pressure on their teeth at night than during the waking hours of the day. This can affect not only your muscles, jaw joint and teeth, but also how much REM (restful) sleep you get each night. The result can be fatigue, chronic malaise, and a general lack of energy.

Many people suffering from TMD complain of chronic headaches, the most common symptom. These headaches are related to muscular spasms, and can be so intense that they are often confused with migraine headaches. They can range in location from the temporal (forehead) area, to the cheekbone area, to the back of the head, to the back of the neck to the mid-back between the shoulder blades. Migraines, on the other hand, tend to be unilateral (on one side of the body) and have much different causes than TMD headaches. Trained neurologists can help you diagnose whether you are experiencing a migraine, and your dentist trained in TMD treatment can help you determine if your pain is joint, muscle or bite related.

One of the most common signs of a TMD problem is "noise" in your jaw joint. This includes such sounds as clicking, popping or grating sounds. Each of these noises represents a different stage of jaw joint breakdown. Clicking and popping sounds occur when the articular disc (spongy pillow of cartilage that sits between the upper and lower jaws) slips out from between the bones. Over time, the disc wears down and eventually becomes perforated. This is the stage when crepitus (grinding/grating noise) is heard in the joint - literally, the sound of bone on bone. At this stage, the disc can luxate (relocate itself) to a position which either does not allow complete opening of the mouth, or complete closing. These are referred to "open lock" and "closed lock" positions respectively. Either situation is serious, as muscle spasms tend to increase due to the improper skeletal position. The ideal goal of early stage TMD treatment is to slow a destructive process and deflect any short term or long term damage that may be sustained by the components of the chewing system.

Further breakdown of the articular disc can result in symptoms including ear pain, dizziness, or ringing in the ear. These symptoms are often mistaken for an earache. Ear, nose and throat specialists are very aware of this confusion, and often refer patients to their dentist when no obvious cause of ear symptoms can be found.

Further, many TMD sufferers are chronically sleep-deprived. They may sleep eight to nine hours per night, but will often still feel restless and tired. Recent studies indicate that the average person generates eight to12 times more pressure on their teeth at night than they do during the day. The generated pain can cause frequent waking and even nightmares. Other studies have shown that chronic nocturnal grinding can reduce REM sleep by up to 80%. One result of REM deprivation is lower secretion of "growth hormone" from the brain, the chemical responsible for repairing damaged tissues in the body. TMD sufferers beat themselves up during the night and at the same time reduce the possibility for natural healing processes to occur. The result is a downward spiral of symptoms which can last a few days to months, even years.

The end result of suffering chronic pain without diagnosis can be as serious as chronic depression. However, depression is multi-factorial (many factors contribute to the disease), so a full evaluation by a medical professional, including your dentist, is necessary.

Causes of TMD 
The average person opens and closes their mouth more than 2000 times per day during the processes of chewing, laughing, yawning, talking, etc. The jaw is placed under a lot of pressure, moved in multiple directions, creating compressive and shear forces against the bones and articular disc. If the supporting structures for the joint (i.e. the teeth and muscles) are unbalanced, then the joint is forced to overcompensate.

UNBALANCED BITE 
If a person has an unbalanced bite it means that the teeth do not come together completely (as they do when you bite down on your back teeth) without first hitting one or more teeth prematurely If this occurs, the posturing muscles are required to move the lower jaw into a new position to get past these teeth. The teeth that meet first are scraped together with excessive force and the powerful chewing muscles contract until the other teeth meet. The body actually memorizes this muscular movement. As the teeth come together, the result is movement of the lower jaw out of the natural socket in the skull where it is supposed to sit.

UNBALANCED MUSCLES
Excessive overloading of muscles to compensate for an unbalanced bite can result in muscular imbalance. This compensation leads to an unhealthy state of the teeth, and people will often experience mild to moderate symptoms, such as headaches and even referred pain to the teeth. As the muscular compensation increases in frequency and magnitude, the symptoms usually increase as well. As the magnitude of the symptoms increase, spastic muscles can actually refer pain to other places in the head and neck regions. It can become very difficult for people to discern what the source of the pain is, often mistaking it for migraine headaches, toothaches, or neck issues. Motor vehicle accident victims often suffer from muscular imbalance caused by acute trauma to the head and neck. Whiplash occurs when there is a sudden lateral shifting of the head and neck secondary to an external force. This can dislocate one or both of the jaw joints, even if there was no direct impact on the jaw. It is the damage to the muscles and ligaments which support the jaw joints that ultimately causes the most discomfort and morbidity to victims.

TRAUMA TO THE HEAD AND NECK
Any form of blunt force to the head and neck area, whether from assault, sports injury, motor vehicle accident, or any other event where muscles, bone and ligaments are damaged, can cause acute and long term damage to the jaw joint. Emergency care is critical in these situations, as delaying treatment may have an effect on the outcome of treatment.

SURGICAL INTUBATION
Intubation is a process whereby a plastic tube is placed down a patient's throat during surgeries involving general anaesthesia. Distention of the mandible forward and backward can dislocate one or both joints, causing postoperative symptoms characteristic TMD: headaches, clicking/popping/grinding noises in the joint, etc. A dentist trained in the care of post-operative TMD can help.

DIAGNOSIS AND TREATMENT OF TMD 

DIAGNOSIS OF TMD 
Diagnosis of Tempero-mandibular Joint Dysfunction (TMD) is a complicated matter. As such it is imperative that the treating dentist do a thorough evaluation of the patient, including history of the condition, dental history, extra-oral (outside the mouth) examination and intra-oral (inside the mouth) examination. Special attention is paid to the tempero-mandibular joint (TMJ) during the examination, which includes:

• TMJ: movement, noises, and tenderness to palpation, range of motion.
• Muscles: spasms, trigger points, and tenderness to touch.
• Bite: including tooth alignment, tooth cracking, harmony with the TMJ.
• X-rays: to examine any changes to the joint.

One of the most reliable diagnostic tools available to a dentist trained in the treatment of TMD is a flat plane bite splint (orthotic). This devise, which is usually clipped temporarily to the lower teeth, allows for stability to be reinstated to the chewing system. In turn, this stabilizes the muscles, often removing symptoms immediately, and removing much of the strain on the TMJ ligaments. Observing how the chewing system reacts during splint therapy will allow the dentist to diagnose more specifically what is occurring in the TMJ itself.

TREATMENT OF TMD Once splint (orthotic) therapy has begun and the dentist can make a more accurate diagnosis of the stage of TMD, a strategy will be developed to more permanently stabilize the TMJ. Part of this strategy may include equilibrating the bite (equalizing teeth biting surfaces), building up the anterior teeth with bonding, veneers or crowns, and/or changing the overall height of the patient's face by performing a full dental rehabilitation. A full rehabilitation is only necessary in the severe and uncommon situation where so much damage has been sustained to the teeth, TMJ, and/or muscles, that most or all of the teeth need to be restored. In rare instances where the TMJ has broken down beyond conventional repair, surgical options may need to be considered.

Dr. Moore has been trained at the L.D. Pankey Institute of Dentistry in Miami, Florida (www.pankey.org). His philosophy is to get to know not only your physical ailments, but also to get to know the patients he treats. In other words, he prefers to focus on the person as a whole, and not just a series of ailments that you may be suffering. A thorough medical history, taken by Dr. Moore, includes topics such as life stress levels, sleeping patterns, and postural issues. This, in conjunction with a thorough physical exam, will allow Dr. Moore to identify issues of concern and the possible options to help his patients recover. He prefers conservative, non-surgical intervention, including homeopathic treatments such as relaxation techniques and meditation. In all cases, Dr. Moore will consult with his patients to ensure that they fully understand their condition and the treatment choices available to them. Once he feels that his patients are in a position to make an informed, educated choice of treatment, it is up to the patients to decide how they wish to proceed.

Typically, treatment is broken into two phases: 

Phase I: Diagnostic/Temporary Solutions

• orthotic splint therapy

Phase II: Treatment/Permanent Solutions

• Orthodontics
• Crown/bridge/veneers/implants
• Full dentures
• Partial dentures
• Composite/onlay buildups of posterior teeth

SELF-ASSESSMENT TEST FOR TMD 
Here are a few questions you may want to ask yourself, to help determine if you have any symptoms of TMD:

Do you ….

Answering "yes" to some or all of these questions may indicate that you suffer from TMD.