The temporomandibular joint — TMJ — is the jaw joint. A person has two such joints; they connect the lower jaw to the temporal bones of the skull on both sides of the head. The joints are located directly in front of the ears, and thanks to them, the lower jaw moves.
Each joint consists of two bones with a cartilaginous disc between them. The joint is surrounded by ligaments and muscles. The TMJ is one of the most frequently used joints in the body. When these joints function properly, a person can speak, chew, or yawn without pain; if not, the person may experience unpleasant symptoms, for example, the jaw clicks and painful sensations occur.
The temporomandibular joint is distinguished by its complex nature, as it provides synchronous and three-dimensional movements. This feature makes it the most complex joint in the human body. In addition, its biological composition differs from other joints that withstand load, such as the hip or knee joints.
What Temporomandibular Disorders Are
Temporomandibular disorders are a complex and insufficiently studied group of conditions characterized by pain in the jaw joint and surrounding tissues, as well as limited mobility of the jaw.
Injuries and other conditions that usually affect other joints of the body, such as arthritis, can also affect the temporomandibular joint. The lesion may involve one or both joints, and depending on the severity, it can affect a person’s ability to speak, chew, swallow, express emotions on the face, and even breathe.
What Causes Temporomandibular Joint Dysfunction
The complexity of such disorders is due to the fact that there may be several causes of this disorder, and in some cases, no obvious cause at all.
Known causes include:
- autoimmune diseases, when the body’s immune cells attack healthy tissues;
- infections;
- injuries in the jaw area;
- dental procedures, even prolonged mouth opening;
- insertion of a breathing tube before surgery;
- various forms of arthritis.
Studies have shown that a certain gene variant increases sensitivity to pain, and this variant is more common in patients with TMJ dysfunction than in the general population. The observation that jaw problems are common in women of reproductive age has prompted research into the role of female sex hormones, particularly estrogen, in the development of TMJ dysfunction. Other risk factors include habits such as frequent chewing of gum or prolonged jaw clenching.
Scientists have established that most patients with TMJ dysfunction also have other painful conditions. Comorbid conditions include chronic fatigue syndrome, chronic headache, endometriosis, fibromyalgia, interstitial cystitis, irritable bowel syndrome, lower back pain, sleep disorders, and vulvodynia. They are called comorbid because they occur together more often than can be explained by chance.
These discoveries stimulate research into the common mechanisms underlying these conditions. TMJ dysfunction is considered a complex disease, similar to hypertension or diabetes, which includes genetic, environmental, behavioral, and sex-related factors.
Symptoms
Pain in TMJ dysfunction is often described as dull and aching, occurring from time to time in the area of the jaw joint and nearby zones. However, some people may not feel pain and still have problems with jaw mobility.
Symptoms may include:
Painful clicking, crunching, or rubbing in the jaw joint when opening or closing the mouth. In TMJ dysfunction, patients often complain of jaw clicking when opening the mouth, chewing, or yawning. Usually, this sound is not very loud and is barely audible only to the patient, but sometimes the clicking can be loud enough for other people to hear. Symptoms associated with sound effects may also manifest as crunching, crepitation — a noise that occurs as a result of friction between bones or cartilage surfaces in the joint — and fluttering sounds.
Stiffness of the jaw muscles, limited movement, or locking of the jaw. When opening the mouth, jaw movements become uneven. In some cases, the patient needs to find a position in which the mouth will open freely. To do this, it is necessary to move the jaw up or down, as well as to the sides.
The symptoms of TMJ dysfunction also include the following conditions:
- a feeling that the bite is “incorrect”;
- dizziness;
- vision problems;
- tinnitus;
- photophobia;
- sleep disorders.
When to See a Doctor
It should be noted that occasional clicking or discomfort in the jaw joint or chewing muscles is quite common and does not always cause concern. Often, the problem disappears on its own within several weeks or months. However, if the pain is severe and lasts more than several weeks, one should consult a doctor.
Whom to Consult
Dysfunctions of the temporomandibular joint — TMJ — the chewing muscles, as well as bite disorders, are diagnosed and treated by a gnathologist.
Gnathology is a branch of dentistry that studies the functioning of the dentoalveolar system and examines how the teeth, jaws, muscles, and joints work.
It is very important to exclude other conditions that may mimic TMJ dysfunction.
For example, facial pain may be a symptom of many diseases, such as:
- sinus or ear infections;
- caries or tooth abscesses;
- different types of headache;
- facial neuralgia;
- tumors.
Diseases such as Ehlers-Danlos syndrome, dystonia, Lyme disease, and scleroderma can also affect the function of the temporomandibular joint — TMJ.
Therefore, first of all, with the help of additional examinations, the doctor must identify the cause that triggers the patient’s various symptoms of the disease, and then choose a treatment plan.
During the examination, doctors can determine whether the patient experiences pain with light pressure on the joint itself or the chewing muscles. The patient’s medical history should not be limited only to the teeth, head, or neck. It should include a complete medical record, which may reveal the presence of one or more comorbid conditions that are often found in patients with TMJ dysfunction.
Sometimes blood tests are recommended to rule out possible medical conditions as the cause of the problem.
Treatment
Most people with TMJ dysfunction have relatively mild or intermittent symptoms that may resolve on their own within several weeks or months with the help of simple home therapy methods. Useful practices include:
- eating soft foods;
- applying ice or heat;
- avoiding excessive jaw movements, such as strong yawning, loud singing, or chewing gum.
If the pain does not go away, doctors prescribe therapy aimed at eliminating or reducing the pain syndrome.
Medication Treatment
- nonsteroidal anti-inflammatory drugs, which reduce pain, swelling, and inflammation;
- antidepressants are prescribed to patients with symptoms that affect working capacity or in cases of sleep disorders;
- agents with a sedative effect also improve sleep quality and reduce irritability;
- botulinum therapy — injection of a special botulinum toxin preparation under the skin — the use of such injections leads to relaxation of the facial muscles, reduction of facial expressions, and slowing of nerve impulse transmission;
- joint blockade using corticosteroids: with long-term TMJ dysfunction, joint damage begins, which requires restoration of its surfaces.
Non-Medication Treatment
- massage, which helps reduce the severity of muscle fiber spasm;
- physiotherapy, such as laser therapy, magnetotherapy, and electrophoresis with medicinal agents.
Dental Treatment
- grinding of teeth and fillings that may interfere with jaw closure;
- dental prosthetics or replacement of a dental prosthesis if it was installed incorrectly;
- bite correction using braces, orthopedic splints, and mouthguards.
Surgical Methods
- myotomy — incision or surgical division of muscle fibers;
- condylotomy of the mandibular head;
- arthroplasty in cases of pronounced changes in the joint capsule.
This article does not replace a medical consultation. For complete and personalized information, please consult your dentist.