"TMJ" stands for temporomandibular joint, or the jaw joint. In fact, there are really two TMJs, one in front of each ear. The TMJ is the joint formed by the temporal bone of the skull (temporo) with the lower jaw or mandible (mandibular). These joints move each time we chew, talk or swallow. Unlike the shoulder or knee, which are ball-and-socket joints, the TMJ is a rotating and sliding joint. The sliding allows for pressure placed on the joint to be distributed throughout the joint and not just in one area. Adding to the joint’s complexity is that between the two bones that make up the TMJ (the temporo and mandibular) is a disc, just like those between the bones on your back. Made primarily of cartilage, in the TMJ the disc acts like a third bone. Because it is attached to a muscle, the disc actually moves with certain movements of the TMJ.

One of the difficulties with diagnosing a TMJ disorder is identifying the exact source of the problem. For example, the nerve to the TMJ is a branch of the trigeminal nerve. An injury to this nerve in the TMJ may be confused with neuralgia because the symptoms appear to be the same. The two bones of the TMJ and disc are held together by a series of ligaments, any of which can be damaged. These ligaments act as guidewires restricting the movements of the jaw and disc. A damaged TMJ ligament usually results in a dislocation of the disc, the lower jaw, or both. Another possible problem may be from muscles that are connected to the bone. A muscle injury may produce pain around the TMJ or abnormal movement of the lower jaw. If there is ligament injury and inflammation in a joint the muscles can splint (tighten up to protect the injured part from Further injury. Careful diagnostic study and testing is needed to determine the precise source of any TMJ problem.

A TMJ disorder is simply a disruption in the function of the jaw, usually accompanied by pain. There are a number of conditions affecting the function of the jaw that can cause one of these disorders. Fortunately, because the jaw is made up of bone and other living tissue, it is alive, making it capable of repair and healing.

Any malfunction prevents the complex system of muscles, bones and joints working together in harmony. The result is a TMJ disorder – also known as TMD (temporomandibular dysfunction) or CMD (cranio-mandibular dysfunction). Generally, a malfunction of one or both of these jaw joints is caused by trauma. Trauma can be macro-trauma (a sudden high impact blow) such as whiplash, sports injuries, or other blows to the lower jaw. Micro-trauma (less impact occurring over a longer period of time) such as tooth grinding (bruxism) and clenching can also be a cause. Bad bite (malocclusion), poor posture, or skeletal malformation, and airway obstructions could be secondary factors . It is estimated that one in every four people suffer from TMJ symptoms.

[ back to top of page ]

Do you have a TMJ problem?

People with TMJ problems generally experience one or more of the following signs & symptoms:

• Chronic recurring headaches
• Clicking, popping or grating sound in the jaw joints
• Earaches, congestion or ringing ears
• Limited jaw opening or locking
. Irregular jaw movements or opening to one side
• Dizziness
• Pain when chewing
• Neck and/or throat pain
• Difficulty in closing the teeth together
• Tired, tight jaws
• Pain behind the eyes
• Scalp tenderness
• Swallowing difficulty
• Pain in the tongue, gums or cheek muscles
• Teeth grinding or clenching

How Is TMJ Diagnosed?

Depending on the nature and severity of the problem, the evaluation of hard tissues my be accomplished using x-rays and CT scans. Soft tissue is evaluated using MRIs, Joint Vibration Analysis (JVA) and electromyography (EMG). Jaw movements are documented using the Jaw Tracker (JT). Occlusion (the bite) is evaluated using the T-Scan. View more information about these diagnostic technologies at the bottom of this page.

The evaluation process will include:

• Detailed Medical and Dental History - A complete medical history must be documented, including all past medical and/or dental problems and treatments, any history of trauma (especially to the head and neck region), specific questions about your symptoms, and the nature and duration of any pain and jaw problems.

• Physical Examination - A complete physical examination for a TMJ problem will likely include:

1. Postural exam to discover any musculoskeletal problems that either contribute to or are the result of TMJ problems. This includes scoliosis, lower back pain and short leg syndrome, among others.

2. A cranial examination to evaluate the planes of the skull, including the alignment of the jaw joints and mouth to the rest of the body (dental plane of occlusion).

3. Dental examination to evaluate the shape of the dental arches, swallowing patterns, tooth wear or fractures, missing teeth, existing dental restorations or other clues. The dentist will usually make models of the mouth so that the teeth and dental arches can be more closely examined.

4. Neurologic examination to test for nerve or brain damage that may cause TMJ symptoms.

5. TMJ examination to look at the ranges of motion, gait, speed and smoothness of jaw movement.

6. Joint Vibrational Analysis, a non-invasive technology that records the vibrations made by joint tissues during movement. Here we are evaluating inflammation, pain and the presence of joint sounds. The patterns and electronic signature of the patient’s joints are compared with known standards for healthy joints, providing objective proof of signs of TMD.

[ back to top of page ]

Causes of TMD

Statistics indicate that the vast majority 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 from a car accident that causes direct trauma to the head or jaw.

The most common forms of trauma that cause TMD are:
• Whiplash (cervical acceleration/deceleration)
• Air bag deployment
• Opening the jaw too wide / Biting on hard objects
• A blow to the jaw
• Bruxism / Clenching


CONTRIBUTING FACTORS
• Bad Bite (Malocclusion)
• Orthodontics
• Ligament Laxity
• Stress
• Systemic Diseases

Other Orofacial Pain Disorders:
There are a number of other pain disorders that are often confused with TMJ because they refer pain into the jaw and joint. Most common among these are:
• Temporal Tendonitis (The "Migraine Mimic")
• Ernest Syndrome
• Occipital Neuralgia
• Trigeminal Neuralgia
• Atypical Trigeminal Neuralgia
• Atypical Face Pain
• Neuralgia Inducing Cavitational Osteonecrosis (NICO)

TMJ Technologies

At the TMJ & Sleep Therapy Centre of Monmouth, we pride ourselves on using the most current, proven and accepted non-invasive diagnostic equipment available to help identify your particular situation and treatment needs. This encompasses leading technologies used to diagnose TMJ problems and monitor treatment progress, including:

• Joint Vibration Analysis (JVA)
• Jaw Tracking (JT)
• Electromyography (EMG)
• BioTENS and BioPAK Bite Registration
• T-Scan II
• Tomography


[ back to top of page ]