Temporomandibular joint and muscle disorders, commonly called “TMJ,” are a group of conditions that causes pain and dysfunction in the jaw joint and the muscles that control jaw movement. Any problem that prevents the complex system of muscles, bones, and joints from working together in harmony may result in temporomandibular disorder.

The two temporomandibular joints, located in front of the right and left ears, connect the lower jaw, the mandible, to the temporal bone of the skull. They are the most complex joints in the body, richly endowed with nerves and muscles that allow coordinated movements in three dimensions. Jaw injuries and various forms of arthritis can give rise to TMJ Disorders but in general, the cause or causes (etiology) of TMJ Disorders is unknown.

What is known that these disorders are more prevalent in women, occurring during the childbearing years. Patients with the most severe chronic and painful TMJ Disorders the ratio of females-to-males approaches 9:1.

Sign & Symptoms

• Pain or tenderness in your face, jaw joint area, neck and shoulders, and in or around the ear when you chew, speak, or open your mouth wide
• Problems when you try to open your mouth wide
• Jaws that get “stuck” or “lock” in the open- or closed-mouth position
• Clicking, popping, or grating sounds in the jaw joint when you open or close your mouth or chew. This may or may not be painful.
• A tired feeling in your face
• Trouble chewing or a sudden uncomfortable bite — as if the upper and lower teeth are not fitting together properly
• Swelling on the side of your face

Causes

• Trauma : injury to the jaw or temoromandibular joint plays a role in some TMJ disorders. But for most jaw joint and muscle problems, scientists don’t know the causes. Because the condition is more common in women than in men, scientists are exploring a possible link between female hormones and TMJ disorders. For many people, symptoms seem to start without obvious reason. Research does not support the popular belief that a bad bite or orthodontic braces can trigger TMJ disorders. There is no scientific proof that sounds— such as clicking—in the jaw joint lead to serious problems. In fact, jaw sounds are common in the general population.

• Myofascial pain. This is the most common form of TMD. It results in discomfort or pain in the fascia (connective tissue covering the muscles) and muscles that control jaw, neck and shoulder function.
• Internal derangement of the joint. This means a dislocated jaw or displaced disk, (cushion of cartilage between the head of the jaw bone and the skull),  or injury to the condyle (the rounded end of the jaw bone that articulates with the temporal skull bone).
• Degenerative joint disease. This includes osteoarthritis or rheumatoid arthritis in the jaw joint.

Medications

Along with other nonsurgical treatments, these medication options may help relieve the pain associated with TMJ disorders:

• Pain relievers and anti-inflammatories. If over-the-counter pain medications aren’t enough to relieve TMJ pain, your doctor or dentist may prescribe stronger pain relievers for a limited time, such as prescription strength ibuprofen.
• Tricyclic antidepressants. These medications, such as amitriptyline, are used mostly for depression, but in low doses, they’re sometimes used for pain relief, bruxism control and sleeplessness.
• Muscle relaxants. These types of drugs are sometimes used for a few days or weeks to help relieve pain caused by TMJ disorders created by muscle spasms.

Therapies

• Oral splints or mouth guards (occlusal appliances). Often, people with jaw pain will benefit from wearing a soft or firm device inserted over their teeth, but the reasons why these devices are beneficial are not well-understood.
• Physical therapy. Along with exercises to stretch and strengthen jaw muscles, treatments might include ultrasound, moist heat and ice.
• Counseling. Education and counseling can help you understand the factors and behaviors that may aggravate your pain, so you can avoid them. Examples include teeth clenching or grinding, leaning on your chin, or biting fingernails.

Surgical or other procedures

• Arthrocentesis. Arthrocentesis (ahr-throe-sen-TEE-sis) is a minimally invasive procedure that involves the insertion of small needles into the joint so that fluid can be irrigated through the joint to remove debris and inflammatory byproducts.
• Injections. In some people, corticosteroid injections into the joint may be helpful. Infrequently, injecting botulinum toxin type A (Botox, others) into the jaw muscles used for chewing may relieve pain associated with TMJ disorders.
• TMJ arthroscopy. In some cases, arthroscopic surgery can be as effective for treating various types of TMJ disorders as open-joint surgery. A small thin tube (cannula) is placed into the joint space, an arthroscope is then inserted and small surgical instruments are used for surgery. TMJ arthroscopy has fewer risks and complications than open-joint surgery does, but it has some limitations as well.
• Modified condylotomy. Modified condylotomy (kon-dih-LOT-uh-mee) addresses the TMJ indirectly, with surgery on the mandible, but not in the joint itself. It may be helpful for treatment of pain and if locking is experienced.
• Open-joint surgery. If your jaw pain does not resolve with more-conservative treatments and it appears to be caused by a structural problem in the joint, your doctor or dentist may suggest open-joint surgery (arthrotomy) to repair or replace the joint. However, open-joint surgery involves more risks than other procedures do and should be considered very carefully, after discussing the pros and cons.

• Moist Heat. Moist heat from a heat pack or a hot water bottle wrapped in a warm, moist towel can improve function and reduce pain. Be careful to avoid burning yourself when using heat.
• Ice. Ice packs can decrease inflammation and also numb pain and promote healing. Do not place an ice pack directly on your skin. Keep the pack wrapped in a clean cloth while you are using it. Do not use an ice pack for more than 10 – 15 minutes.
• Soft Diet. Soft or blended foods allow the jaw to rest temporarily. Remember to avoid hard, crunchy, and chewy foods. Do not stretch your mouth to accommodate such foods as corn on the cob, apples, or whole fruits.
• Over the-Counter Analgesics. For many people with TMJ Disorders, short-term use of over-the-counter pain medicines or nonsteroidal anti-inflammatory drugs (NSAIDS), such as ibuprofen, may provide temporary relief from jaw discomfort. When necessary, your dentist or doctor can prescribe stronger pain or anti-inflammatory medications, muscle relaxants, or antidepressants to help ease symptoms.
• Jaw Exercises. Slow, gentle jaw exercises may help increase jaw mobility and healing. Your health care provider or a physical therapist can evaluate your condition and suggest appropriate exercises based on your individual needs.
• Relaxation Techniques. Relaxation and guided imagery can be helpful in dealing with the pain that accompanies TMJ dysfunction. Deep, slow breathing enhances relaxation and modulates pain sensations. Some have found yoga, massage, and meditation helpful in reducing stress and aiding relaxation.
• Side Sleeping. Sleep on your side using pillow support between shoulder and neck.
• Relax Facial Muscles. Make a concerted effort to relax your lips, and keep teeth apart.
• Yawning. Use your fist to support your chin as you yawn to prevent damage to the joint and prevent your jaw from locking open.

In addition, avoid:

• Jaw clenching.
• Gum chewing.
• Cradling the telephone, which may irritate jaw and neck muscles.

References :

https://emedicine.medscape.com/article/809598-overview

https://www.mayoclinic.org/diseases-conditions/tmj/symptoms-causes/syc-20350941

https://www.aafp.org/afp/2015/0315/p378.html

https://www.hopkinsmedicine.org/health/conditions-and-diseases/temporomandibular-disorder-tmd

http://www.tmj.org/Page/51/32