Diseases Of The Temporomandibular Joint And Their Treatments

The temporomandibular joint (TMJ) is located in the lower part of the temporal bone between the mandibular fossa and the mandibular condyle. It is located in front of the external auditory canal. This joint may show morphological differences from person to person. Even in the same person, the right and left joints can be morphologically different. This joint makes a hinging and sliding movement.

TMJ MOVEMENTS

The effective movement of the temporomandibular joint depends on the harmony of the occlusal relationship between the teeth and the structures of the musculature in the craniomandibular region. The main movements of the mandible are: Lateral, protrusive and depressive movements.

The temporomandibular joint performs two types of movements, rotational movements (rotation) and translational movements (sliding movements). Rotational movement occurs between the condyle of the mandible and the articular disc. Translation occurs between the temporal bone and the condyle-disc complex.

The normal mouth opening is 35-50 mm. 15 mm of this movement is provided by translation and 25 mm by rotation. The rest position of the temporomandibular joint is the position where the lips are together, the mouth is slightly open, the teeth are not touching and the first half of the tongue is on the hard palate.

 

CLASSIFICATION OF TMJ COMPLAINTS

1. disorders of the masticatory muscles, local muscle pain, myofascial pain, myositis, myospasm and others.
2. temporomandibular joint disorders, inflammatory disorders of the temporomandibular joint, irregularities in the condylar-disc complex, structural incompatibility of the joint surfaces.
3. chronic hypomobility of the mandible (lack of movement), ankylosis, muscle contractures, coronoid impedance.
4. developmental disorders, congenital and developmental bone diseases, congenital and developmental muscle diseases.

Let’s look at some of these diseases:

IRREGULARITY IN THE CONDYL-DISC COMPLEX

It is the disruption of the normal anatomical structure of the disc and condylar relationship that prevents free movement of the joint and causes a clicking (sudden noise), temporary catching sensation, clicking and locking. Approximately 30-50% of the general population have TMJ clicking. Most of these patients are likely to have a dislocation of the disc, but may not have experienced any pain. The most common cause of this disorder is trauma to the condyle-disc complex. While macrotrauma, especially when the mouth is open, causes ligament lengthening, microtrauma such as chronic muscle hyperactivity can also be counted among the causes.

ARTHRITIS

The most common arthritis in TMJ is degenerative arthritis. Clinical symptoms are present in 16% of the general population. In asymptomatic patients, there is radiographic evidence in 44%. While stress and trauma to the TMJ during its activity cause secondary osteoarthritis, primary degenerative arthritis is usually seen in older patients. Primary osteoarthritis rarely causes discomfort, only mild discomfort. Secondary osteoarthritis can occur between the ages of 20 and 40 and is painful. Joint tension, joint pain that increases with function, and restriction of mouth opening are observed in these patients. In advanced stages of the disease, crepitation may be audible.

MYOFASCIAL PAIN SYNDROME

In this syndrome, muscle spasms, stiffness, tenderness, fatigue and restriction of joint movement are observed in the tense ligaments in the muscles that are the source of the trigger points or muscle spasms that accompany the pain.

PSORIATIC ARTHRITIS

Blockage of the temporomandibular joint is a rare condition. It starts suddenly and some of these patients develop chronic skin lesions. Erosive changes are usually observed in the glenoid fossa and condyle and are associated with excessive narrowing of the joint space.

RHEUMATOIDE ARTHRITIS

In almost half of the patients with rheumatoid arthritis, the temporomandibular joint is also affected. This effect is seen in severe cases and is usually bilateral. In these patients, condylar support is lost and an open bite is seen.

CHRONIC MANDIBULAR HYPOMOBILITY

It is the restriction of jaw movements due to adhesions formed on the intracapsular surfaces of the temporomandibular joint. Due to ankylosis, the mandible cannot perform translational movements and the range of motion of the joint is significantly limited. The most common cause of ankylosis is macrotrauma. Trauma causes bleeding in the joint. Another common cause of trauma is TMJ surgery. Fibrotic changes in the capsular ligaments during surgical procedures lead to a restriction of mandibular movements.

HYPERURICAEMIA (GUT)

Changes in a person’s diet can lead to hyperuricaemia. The high serum uric acid level leads to accumulation of urate in the synovial fluids and hyperuricaemia in the joint. TMJ involvement is usually seen in men over 40 years of age and is bilateral. The joint becomes painful, swollen, tight and red. The treatment approach is initially medical, but if control is not achieved, surgical debridement may be performed.

NEOPLASIA

The most common benign tumour of the temporomandibular joint is osteochondroma, and its malignant tumour is osteosarcoma or chondrosarcoma. Metastases from breast cancer are also possible.

TREATMENT OPTIONS FOR THE TEMPOROMANDIBULAR JOINT

1. patient education: every person with TMJ disorders should be educated about prevention programmes. The protective programme includes the following elements;

– Eat in small bites, avoid one-sided chewing. – Eat soft foods, avoid hard foods such as peanuts and hazelnuts.

– Breathe deeply and through the nose rather than superficially and through the mouth.

– Support the chin when laughing or yawning.

– Avoiding parafunctional activities (pencil biting, gum chewing, teeth clenching, thumb sucking…).

– Proper use of the resting position (teeth apart, lips together, tongue loose on the palate).

– Avoid slouching and make sure that the head and shoulders are kept upright.

– Avoid lying face down.

2. physiotherapy: TENS, biofeedback, surface and deep heating, cold massage, trigger point injection, iontophoresis, phonophoresis, therapeutic exercises, acupuncture, mobilisation and posture training are used for this treatment. These treatment methods can relieve musculoskeletal pain, restore normal functions, regenerate and repair tissues.
3. medical treatment: analgesics, corticosteroids, antidepressants and muscle relaxants can be used to prevent pain and reduce inflammation, if present. Although these medications can be used in combination with other treatments, they can sometimes be sufficient on their own.
4. bite block therapy: removable bite blocks are used to cover the occlusal surfaces of the teeth of one jaw and allow contact with the opposing teeth. It is generally defined as a night plate, bite guard, orthopaedic appliance or interocclusal appliance. These devices are effective in relieving pain and correcting dysfunction in the jaw.
5. surgical treatment: In patients with painful TMJ clicking, locking or mandibular dysfunction and where conservative treatment is unsuccessful, surgical treatment may be considered. Surgical treatment may be considered in 5% of patients with TMJ.

• Arthrocentesis is the first stage of treatment. Washing ensures the reduction of mediators that cause intra-articular infection. Arthrocentesis uses saline and can be administered with a single or double needle.
• Arthroscopy is performed to detect intra-articular irregularities.
• Arthrotomy, is used for neoplasia such as chondroma, developmental disorders such as fibrous or bony ankylosis, condylar hyperplasia. In patients whose results are not achieved with arthroscopy and arthrocentesis, open surgery should be performed to reposition the slipped disc. If the disc is severely damaged and cannot be repositioned, or if there is a tear in the retrodiscal structures of the disc that cannot be repaired, the disc should be removed. Although some patients do well with a disc joint, some surgeons prefer autogenous material such as skin grafts, ear cartilage or temporal muscle flaps instead of discs.
• Arthroplasty is an acceptable alloplastic material application that can replace the natural disc.

When considering treatment options for TMJ disorders, non-surgical options should be preferred first and medical treatment initiated. At the same time, appropriate physical treatments should be tried. If necessary, surgery should be performed immediately. However, it should be remembered that in cases where surgery is performed and there is no successful outcome, repeating the procedure or performing different surgical interventions will not significantly change the outcome.

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