Anatomy Of The Temporomandibular Joint Health And Social Care Essay

The temporomandibular joint (TMJ) is a synovial ,condylar, and hinge-type joint with fibrocartilaginous surfaces and an articular disc. It is directly located in front of the ear on either side of the head where the upper jaw(maxilla) and lower jaw(mandible) meet. The disc divides each joint into two cavities and provides congruent contours and lubrication for the joint.

In the resting position, the mouth is slightly open, the lips are together and the teeth are not in contact but slightly apart, however, in the close packed position, the teeth are tightly clenched and the heads of the condyles are in the posterior aspect of the joint (Magee,2006).

The TMJ is complex and composed of muscles, tendons and bones and I is innervated by branches of the auriculotemporal and massetteric branches of the mandibular nerve. The temporomandibular, or lateral, ligament restrains movement of the lower jaw and prevents compression of the tissues behind the condyle, however, the sphenomandibular and stylomandibular restrains to keep the condyle, disc and temporal bone opposed (Magee, 2006).

The TMJ can be located by putting a finger on the triangular structure in front of the ear and the finger is moved just slightly forward and pressed firmly while opening the jaw (medicineNet.com)

TMJ disorder, which is also called TMJ syndrome, results from pressure on the facial nerves due to muscle tension or abnormalities of the bones in the area of the hinge joint. In addition, TMJ disorder is sometimes referred to as myofacial pain dysfunction and costen’s syndrome (Berktow, 1997).

Causes:

This disorder occurs due to many conditions and behaviors. First, teeth grinding and teeth clenching (bruxism), which results when the patient unconsciously develops an uncontrollable clenching and grinding of the teeth. This may be due to psychological stress. Bruxism can lead to severe damage to the teeth, condyle and muscular balance around the joint with symptoms of fatigue. Second, osteoarthritis and rheumatoid arthritis can cause TMJ disorder. Another cause is internal derangement, which is a condition in which the cartilage disc moves from its proper position making a clicking or popping noise while moving ,and rarely the disc is permanently out of position.

Hypermobility is another condition that causes the TMJ disorder. In this condition, the ligaments that hold the jaw in place are too loose and the jaw tends to slip out its socket. Dental problems and misalignment of the teeth are also among the causes of TMJ disorder, in which patients has difficulty in finding a comfortable bite or the way that their teeth fit together has changed (Magee, 2006).

In addition, people who are under stress, they release their nervous energy by both consciously or unconsciously grinding and clenching their teeth. Lastly, some of the least frequent causes of TMJ disorder include occupational tasks such as holding the telephone between the head and shoulder, birth abnormalities, and habitual gum (medicineNet.com).

Symptoms:

The symptoms of TMJ depend on the cause and severity of the disorder. The most common symptom is ear pain, where about 50% of patients with TMJ disorder suffer from ear pain with no ear infection and this pain is felt in front of the ear. Headaches and difficulties in speaking is another symptom of TMJ disorder. The pain becomes worse while opening and closing the jaw and it increases when the patient is exposed to cold weather. Also, sound or crepitus are common in patients with TMJ disorder and these sounds are sometimes accompanied by increasing pain. In addition, ringing in the ear, dizziness, balance problems and feelings of fullness are among the symptoms related to TMJ disorder (medicineNet.com; Robert, 1997).

Diagnosis

TMJ disorders are most frequently diagnosed by dentists based on physical examination of the patient’s face and jaw. The examination might include palpating the jaw muscles for soreness or asking the patient to close and open the jaw to check for misalignment of the teeth in the upper and lower jaw. Furthermore, TMJ disorder can be diagnosed by X-rays and MRI scans, however, these two tests are not commonly used to diagnose TMJ disorder. Arthrography is another technique that might be used to diagnose TMJ disorder, in which a special dye is injected into the joint ,which is then x-rayed (Robert, 1997).

Types of Treatment

Medications and Surgeries:

In some cases, the symptoms of TMJ disorders may disappear without treatment, but if symptoms persist, medications are recommended. Nonsteroidal anti-inflammatory drugs (NSAIDS) such as aspirin or ibuprofen, usually don’t provide enough relief for pain caused by TMJ disorders. However, antidepressant such as nortriptyline has proved effective in relieving TMJ pain. Also, muscle relaxants and corticosteroid drugs are used for significant pain and joint inflammation. In very rare cases, surgery may be required to repair or replace the joint. The disk between the mandible and temporal bone might be removed and this surgery may be beneficial. While in advanced osteoarthritis, a partial or total joint replacement may help remove bone-on-bone contact and improve joint mechanics and motion (mayoclinic.com).

Physical Therapy Role in the Treatment of TMJ Disorders

Physical therapy assessment includes:

Patient history:

The physiotherapist should know the past and present medical history of the patient. There are many questions that should be asked by the physiotherapist. The first question is about pain, if pain occurs on opening or closing of the mouth, or if the pain is felt in the fully opened position. This is because pain associated with opening the mouth to bite an apple is probably caused by an extra-articular problem, whereas pain associated with biting firm objects, such as nuts is probably caused by an intra-articular problem (Magee, 2006).

The second question is related to pain while eating; whether the patient chew on the right or left side or both sides equally. Also, the physiotherapist should ask about the movement of the jaw that causes pain and should watch the patient’s jaw movement while the patient is talking. The physiotherapist should ask if the patient complains of any clicking because it is a result of abnormal motion of the disc and mandible (Magee, 2006).

The next question is about the locking, which may indicate if the mouth doesn’t fully open or doesn’t fully close. If the jaw has locked in the closed position, the locking is probably caused by a disc with the condyle being posterior or anteromedial to the disc, while if the jaw has locked in the opened position, it’s probably caused by subluxation of the joint or by posterior disc displacement (Magee, 2006).

Finally, the physiotherapist must know if the patient has any habitual head postures, because holding the telephone between the ear and the shoulder compacts the TMJ on that side (Magee, 2006).

Observation:

When assessing the TMJ, the physiotherapist must assess the posture of the cervical spine and the head. The physiotherapist should check if the face is symmetrical horizontally or vertically and if facial proportions are normal. The physiotherapist should also check the eyebrows, eyes, and ears and the corners of the mouth for symmetry on both horizontal and vertical planes. In addition, it’s important to check if there is any malocclusion that may result in a faulty bite. Malocclusion is defined as any deviation from normal occlusion, which may be a major factor in the development of disc problems of the TMJ and occurs when the teeth are in contact and the mouth is closed.

Furthermore, the physiotherapist should note if the patient demonstrates normal bony and soft tissue contours. When the patient bites down, the therapist should check the masseter muscles bulge because some patients may have hypertrophy, which is caused by overuse and may lead to abnormal wear of teeth. The physiotherapist should also observe if the patient is able to move his tongue properly and if he can move it up towards and against the palate to check for tongue thrusting. Tongue thrusting is defined as forward movement of the tongue which usually occurs to push against the lower teeth and it also occurs when the tongue is pushed against the upper teeth and the lower teeth are closed firmly against it; creating an oral seal (Magee, 2006).

Other questions that can give the physiotherapist an idea of the mobility of the mouth and jaw structures and their neurological mechanisms include the following: where does the tongue rest? Is the tongue bitten frequently? Does the patient swallow normally? Do the facial muscles tighten on swallowing?

Examination:

A. Active movements:

With the patient in the sitting position, the physiotherapist observes the active movements of the head and neck, making note of any deviation or decrease in Range of motion. The patient is first asked to perform active movements of the cervical spine. During flexion of the neck, the mandible moves up and forward and the posterior structures of the neck become tight. However, during extension the mandible moves down and back and the anterior structures of the neck become tight. The physiotherapist notes if the pateint can flex and extend the neck while keeping the mouth closed or while the pateint opens the mouth to do these movements (Magee,2006).

The patient should be asked to place a fist under the chin and then open the mouth and the lower jaw against it. If the mouth opens in this way, movement of the neck into extension is occurring because the head is rotating backwards on the temporomandibular condyles. This test movement is important especially if the patient subjectively feels that there is a loss of neck extension. With the neck movements, the physiotherapist continues to note the active movements of the TMJ (Magee, 2006).

The movements of the mandible can be measured with a millimeter ruler or vernier calipers. The protrusion of the mandible can be measured by asking the patient to protrude or jut the lower jaw out past the upper teeth. The normal movement is 3 to 6 mm; measured from the resting position to the protruded position. On the other hand, the retrusion of the mandible can be measured by asking the patient to retrude or pull the lower jaw back as far as possible. The normal range of movement is 3 to 4 mm (Magee, 2006).

For the lateral deviation, the teeth are slightly disoccluded and the patient moves the mandible laterally, first to one side then to the other. With the joints in the resting position, two points are picked on the upper and lower teeth, which are at the same level. When the mandible is laterally deviated, the two points are measured giving the amount of lateral deviation. The normal range of motion of the lateral deviation is 10 to 15 mm. Any lateral deviation from the normal opening position or abnormal protrusion to one side indicates that the lateral pterygoid, masseter, or temporalis muscle , the disc or the lateral ligament on the opposite side is affected (Magee, 2006).

B. Passive movements:

Passive movements are carried out for the TMJ when the physiotherapist is attempting to determine the end feel of the joints. The normal end feel of these joints is tissue stretch on opening and teeth contact (bone to bone) on closing.

C. Resisted isometric movements:

It is difficult to test resisted isometric movements of the TMJ. The jaw should be in the resting position and the physiotherapist applies gentle resistance to the joints and asks the patient to hold the position. For testing the opening of the mouth (depression), the physiotherapist applies resistance at the chin by using a rubber glove over the teeth with one hand and the other hand rests behind the head or neck for stabilization. On the other hand, for testing the closing of the mouth (elevation or occlusion), one hand is placed over the back of the head or neck to stabilize the head while the other hand is placed under the chin and the patient is asked to slightly open his/her mouth to resist the movement. Lastly, to measure the lateral deviation of the jaw, one of the examiners hand is placed over the side of the head above the TMJ to stabilize the head. The other hand is placed on the jaw of the patient’s slightly open mouth, and the patient is asked to push out against it (Magee, 2006).

D. Functional assessment:

After testing the basic movements of the TMJ, the physiotherapist should test functional activities of daily living involving the use of the TMJ. These activities include: chewing, swallowing, coughing, talking, and blowing.

E. Special tests:

There are no routine special tests for the TMJ. The Chvostek test is used to determine if there is a pathology involving the seventh cranial (facial) nerve. The physiotherapist taps the parotid gland overlying the masseter muscle, if the facial muscle twitches, the test is positive. Also, the examiner can listen to the TMJ during movement. The movements include opening and closing of the mouth, lateral deviation of the mandible to the right and left, and mandibular protrusion. Normally, only on occlusion there will be a sound to be heard. On the other hand, crepitus is usually indicative of degenerative joint disease or perforation in the disc. Painful crepitus means that the disc has eroded, in which the condyle bone and temporal bone are rubbing together (Magee, 2006).

F. Reflexes and coetaneous distribution:

The reflex of the TMJ is called the jaw reflex. The examiner’s thumb is placed on the chin of the patient while the patient’s mouth is relaxed and opened in a resting position. The patient is asked to close his eyes. The examiner then taps the thumbnail with a neurological hammer. The physiotherapist should be aware of the dermatome patterns for the head and neck as well as the sensory nerve distribution of the peripheral nerves. Pain may be referred from the TMJ to the teeth and neck, and vice versa (Magee, 2006).

G. Palpation:

To palpate the TMJ, the examiner places the fingers in the patient’s external auditory canals and ask the patient to actively open and close the mouth. Then the examiner determines if both sides are moving simultaneously. Then the examiner places the index finger on the mandible condyles and feels for pain or tenderness on opening and closing of the mouth (Magee, 2006).

Physical Therapy Treatment

Patients who have difficulty with bruxism are usually treated with a plastic splint ,which is given to the patient to place over the teeth before going to sleep. Splints can also be used to treat some cases of internal derangement by holding the jaw forward and keeping the disc in place until the ligaments tighten.TMJ disorders can also be treated with ultrasound, electromyographic , biofeedback, stretching exercises, electrical nerve stimulation, and friction massage. Also, applying warm, moist heat to the side of the injury can help in relaxing the muscles and decreasing the pain (Robert, 1997; myoclinic.com).

Conclusion

Temporomadibular joint disorder is a term referring to a problem with the jaw function. This disorder is caused by many factors and behaviors such as trauma, bruxism, malocclusion and stress. These causes are resulting in many symptoms which are: ear pain, grinding sound in the jaw joint, headaches and jaw pain or stiffness. It can be treated by many ways. Drugs are one option of the treatment such as antidepressants. Another option is surgery which is rarely used. Physical therapy intervention plays a role in the management of the TMJ disorders. Jaw exercising, moist heat, massage and electrical stimulation are examples of physical therapy treatment.