Temporomandibular Joint Syndrome (TMJS)

The temporomandibular joint (TMJ) is a gliding joint, formed by the condyle of the mandible and the temporal bone. The articulating surfaces of the mandible and temporal bone are separated by an articular disk (meniscus), which divides the joint cavity into 2 small spaces. The articular disk provides the gliding surface for the mandibular condyle, resulting in smooth joint movement.

Temporomandibular joint syndrome (TMJS) is the most common cause of facial pain after toothache. No unequivocal definition of the disease exists; discrepancies concerning the terminology, definitions, and practical treatment methods hinder uniform conception from becoming effective. TMJS can be classified broadly as (1) TMJS secondary to myofacial pain and dysfunction (MPD) and (2) TMJS secondary to true articular disease; the 2 types can be present at the same time, making diagnosis and treatment more challenging.

MPD type forms the majority of the cases of TMJS. Associated with pain without apparent destructive changes of TMJ on x-ray, it is characterized by its polyetiological nature and frequently is associated with bruxism and daytime jaw clenching in a stressed and anxious person. True intra- articular disease can be further specified as disk displacement disorder, chronic recurrent dislocations, degenerative joint disorders (DJDs), systemic arthritic conditions, ankylosis, infections, and malignancy.

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In MPJS, the etiological basis of the symptomatology (ie, pain, tenderness, and spasm of the mastication muscles) is muscular hyperactivity and dysfunction due to malocclusion of variable degree and duration. The significance of psychological factors has been recognized during the past few years.

In TMJS of articular origin, disk displacement is the most common cause. Abnormal anterior displacement causes pain, pops, and crepitus; full jaw opening may not be possible. Inability to attain a jaw opening of more than 10 mm is known as closed lock. In TMJS of articular origin, the spasm of the mastication muscle is secondary in nature. The other causes of TMJS of articular origin are diseases such as DJD, rheumatoid arthritis (RA), ankylosis, dislocations, infections, and malignancy, the pathophysiology of which are self-explanatory.



TMJS is a commonly seen condition in primary care and dentistry practice. The incidence is ever increasing. At any given time more than 10 million people in the United States are believed to be affected by this painful condition. TMD primarily affects women, more so young women. The male- to-female ratio is 1:4. Highest incidence is among young adults, especially women aged 20-40 years.


Symptoms are as follows: Pain: It usually is periauricular, associated with chewing, and may radiate to the head but is not like a headache. It may be unilateral or bilateral in MPD, and usually is unilateral in TMJS of articular origin, except in RA. In MPD, the pain may be associated with history of bruxism, jaw clenching, stress, and anxiety; the pain may be more severe during periods of increased stress. The assessment of pain is based principally on subjective estimation by the examining practitioner. Click, pop, and snap: These sounds usually are associated with pain in TMJS. The click with pain in anterior disk displacement is due to sudden reduction of the posterior band of the disc to normal position. An isolated click is very common in the general population and is not a risk factor for development of TMD. Limited jaw opening and locking episodes: The lock can be open or closed; open lock is inability to close the mouth and is seen when the mandibular condyle dislocates anteriorly in front of articular eminence; if not reduced immediately, it is very painful. Closed lock is an inability to open the mouth because of pain or disk displacement.

Headaches: The pain of TMJS is not like a usual headache. TMJS may act as a trigger in patients prone to headaches, and when present in association with TMJS, they tend to be severe in nature. Some patients may have a history of headaches resistant to treatment; the diagnosis and treatment of TMJS trigger should not be overlooked in such patients as it is essential for treating these headaches.

Other symptoms associated with TMD are otalgia, neck pain and/or stiffness, shoulder pain, and dizziness. About one third of these patients have a history of psychiatric problems. History of facial trauma, systemic arthritic disease, and recurrent dislocation also should be elicited.



The following findings may be noted: asymmetry, muscle hypertrophy, malocclusion of jaw, abnormal dental wear, and missing teeth, limited range of motion with vertical jaw opening between the incisors less than 5 cm and protrusive and lateral mandibular movement less than 1 cm. Also, during the physical exam, joint popping can be palpated and auscultated and is often associated with muscles spasm and tenderness.

Imaging Studies:

Imaging of the TMJ is an area of ongoing research these days. A variety of new imaging techniques are being used and perfected to study TMJ. Conventional radiography is the most utilized imaging study. It is simple, evaluates bony structures, and in most cases is sufficient. It involves specific techniques and views such as modified Schuller views of each TMJ, both open mouth and closed mouth. Radiographic findings in TMJ depend on the etiology of TMD; in cases of RA and seronegative spondyloarthropathies, plain films show erosions, osteophytes, subchondral bony sclerosis, and condylar-glenoid fossa remodeling.

Conventional tomograms are no longer indicated. CT scan should be used in place of conventional tomograms. CT scan can explore both bony structures and muscular soft tissues. MRI, though costly, should be used as the study of choice if (1) an articular or meniscal pathology is suspected and an endoscopic or surgical procedure is contemplated and (2) in a case of traumatic TMJS.

Studies have shown that there is a high degree of agreement between MRI, arthroscopic, and surgical findings and conclude that MRI should be the study of choice in the evaluation of TMJ disease.



Diagnostic arthroscopy is an acute diagnostic approach. It should be used mainly in patients suffering from internal TMJ derangements resistant to conservative treatments. A good MRI study should be obtained before contemplating arthroscopy.

Medical Treatment:

Most cases of TMJS are self-limiting and do not get worse; simple treatment, involving self-care practices, rehabilitation aimed at eliminating muscle spasms, and restoring correct coordination, is all that is required. Nonsteroidal anti- inflammatory analgesics (NSAIDs) should be used on a short- term, regular basis and not on an as needed basis.

On the other hand, treatment of chronic TMJS can be difficult and the condition is best managed by a team approach; the team consists of a primary care physician, a dentist, a physiotherapist, a psychologist, a pharmacologist, and in small number of cases, a surgeon. The different modalities include patient education and self-care practices, medication, physical therapy, splints, psychological counseling, relaxation techniques, biofeedback, hypnotherapy, acupuncture, and arthrocentesis.

The treatment of chronic TMD is difficult, and at some time during the course of the disease surgical options are discussed with the patient. Some of the surgical options are described here. Simple washing of the upper compartment of TMJ using arthrocentesis has been very effective in patients with a history of condylomeniscal incoordination; results have been comparable to those of arthroscopic surgery.Arthroscopic surgery indications include internal derangements, adhesions, fibrosis, and degenerative joint diseases. It appears to be as efficient as open surgery, causes less surgical morbidity, and has few severe complications as compared to open surgical procedure. Open surgery was the main surgical option in the 1970s and 1980s, and the most common procedure was disk repositioning and plication; in cases of severe disk damage, procedures such as disk repair and removal were done using artificial or autogenous material. These procedures have since fallen out of favor.


Physical Therapy:

Apart from patient education and pain control, the main goal of physical therapy is to stabilize the joint and restore its mobility, strength, endurance, and function. Common modalities used to accomplish these goals are the following: Relaxation training using electromyographic (EMG) biofeedback: The patient first is educated about the contribution of stress and muscular hyperactivity to pain. An EMG monitor provides instant feedback to patients about the state of their muscle activity and allows the patient to easily correlate pain with hyperactivity of the muscles and decrease in pain with relaxation.

Friction massage: The hypothesis is that temporary ischemia and resultant hyperemia, produced by firm cutaneous pressure during massage, helps inactivate trigger points. Friction massage also may help disrupt small fibrous adhesions in the muscle formed as a result of surgery, injury, or prolonged restricted motion.

Ultrasonic treatment: ultrasonic waves produce tissue heating at a deeper level than moist heat; this increase in local tissue temperature leads to increase in blood flow and removal of metabolic byproducts responsible for pain and may help decrease adhesions by disrupting collagen cross- linkage. It also may help decrease intra-articular inflammation. To be effective, ultrasonic treatment should be done every other day, using about 1 watt/cm2 for approximately 10 minutes over the affected muscles and joints.

Transcutaneous electronic nerve stimulation: Electronic stimulation of superficial nerve fiber overrides the pain input from mastication muscles and TMJ, causing release of endogenous endorphins. In some patients it provides longer duration of pain relief than the time during which the stimulation is actually applied.

Cognitive-behavioral treatment: This consists of hypnosis, cognitive coping skills, and relaxation. Hypnotic susceptibility correlates with reductions in reported pain.

Chronic painful conditions worsen any preexisting anxiety or depression. In appropriate settings, psychological counseling may provide benefit.


Medical/Legal Concerns:

TMJS should be diagnosed and treated promptly. Delays in management are usually associated with compromised treatment efficacy, and a longer duration of disease. Overly aggressive treatment, on the other hand, can also make the condition worse. Surgery is generally thought of as a last option. Patient education and informed consent regarding the condition are important for a successful outcome. Timely referrals to TMU experts are also advisable.

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