JOSEPH R. ANTICAGLIA MD
Medical Advisory Board
INTRODUCTION
Temporo-Mandibular Joint Disorders JMJD (also known as TMJ or TMD) describe a variety of conditions that cause pain and dysfunction of the jaw joint. These include the muscles of the jaw or related muscles and nerves in the head and neck area.
Ordinarily we don’t think about the mandible (the jaw bone), but it moves every time you swallow, talk, or chew. It glides forward when you pout and opens wide when you yawn. The TMJ is located in front of each ear and connects the mandible to the temporal bone of the skull (the bone on the side of the head).
When things are going well, we take for granted such actions as chewing, talking or yawning. But things were not going well for Jessica. Jessica was having a good time at a picnic until she bit into corn on the cob. She experienced a sudden jabbing pain in her left ear, tenderness over the TMJ region and could not chew anything without provoking severe ear pain and discomfort on the left side of her face. Shortly thereafter, she couldn’t clench her teeth nor open her mouth fully. Soups and liquids became her diet. The discomfort lasted two days before she was able to see her doctor who said:
“Please, open your mouth and say, Ah.” “I can’t. I can’t open it any further than this” Her doctor gently palpated the TMJ area and she said, “Ouch!” Was it the jaw joint or the muscles that are attached to the jaw joint that caused her problem? Or was it neither of these two or both?
Separating the mandible from the temporal bone is a small disc of cartilage that acts like a cushion, preventing the mandible from grinding against the temporal bone of the skull. This cartilage allows for the hinge-like, gliding movements of the mandible.
If you put your finger in front of the middle part of your ear and open your mouth, you can feel the area of the TMJ. The round, upper end of the mandible is called the condyle and it slides alongside the fossa (socket) of the temporal bone. You can check the condylar motion by carefully placing your 5th “pinky” finger in the ear canal and open and close your mouth. Is it clicking, popping or making grinding sounds? What are the symptoms of TMJ?
SIGNS & SYMPTOMS
- Jaw joint pain
- Ear pain
- Cheek, temple, neck pain
- Locking of jaw
- Difficulty opening & closing mouth
- Joint sounds
- Bruxism (grinding your teeth)
These are the more frequently encountered signs & symptoms of TMJ. The pain can be jabbing or dull, acute or chronic, be localized to the jaw joint or can give you a headache when it spreads to different parts of the head and neck region. Joint sounds (popping, clicking, grinding sounds) unaccompanied by other symptoms, in general, do not need treatment. In contrast, joint sounds accompanied by pain means you should see your doctor.
Often patients complain that they cannot eat, chew or bite down without experiencing pain. Some patients complain of tinnitus (ringing in the ears), dizziness, ear fullness or hearing loss with TMJ. If that is the situation, it’s advisable to obtain an ENT consultation.
WHAT CAUSES TMJ?
TMJ disorders may be classified into three main categories: Myofascial pain syndrome (MPS) causes achiness or jabbing pain in the muscles that control jaw movement. The second category is arthritic conditions and third is jaw joint derangements, where the cartilaginous disc between the jaw bone and the temporal bone of the skull deteriorates or is displaced out of position causing TMJ.(1)
TMJ is more prevalent in women and occurs more frequently in the younger age group. Many factors are associated with the etiology (cause) of TMJ and the exact cause at times is uncertain.(1,2)
MUSCLE DISORDERS
Myofascial Pain Syndrome (MPS) is the most common TMJ problem. It involves the chewing muscles of the jaw or the connective tissue that covers these muscles. The pain can be sharp or dull, made worse with jaw movement and clenching of the jaw. If you place your fingers near the angle of the jaw and bite down, one of chewing muscle, the “masseter” muscle will pop up.
In patients with MPS, the masseter muscle can be very sensitive to touch, so that if you press on it you’ll not only elicit an “ouch,” as in Jessica’s case, but “trigger” pain at a distance call referred pain. Patients report this referred pain as facial discomfort, headache, neck pain, or ringing in the ears or dizziness.
Besides MPS, patients experience discomfort when the chewing muscles (muscles of mastication) become inflamed, go into painful spasm or contract as can happen after the jaw is wired and immobilized after surgery.
Myositis
Myositis is an inflammation of muscle tissue for example secondary to an injection in the TMJ area or oral surgery. The involved area can be swollen, red causing painful limitation of jaw movement.
Myospasm (Trismus)
Myospasm is a ‘muscle cramp’ resulting in an inability to open the mouth due a spasm of the TMJ muscles. It causes severe pain that usually goes away within a few hours but it can last longer. Extraction of third molar teeth, injection of anesthesia to the jawbone region can cause the muscles to “cramp up.”
Fibromyalgia
Fibromyalgia is a widespread painful disorder affecting the muscles, bones and joint on both sides of your body, above and below the waist of uncertain etiology (cause). The muscle pain of TMJ may just be a part of this more generalized muscle disorder. Research indicates up to 20% of TMJ patients with muscle complaints really have Fibromyalgia.(3)
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In Part 2 shall be discussed: Jaw Joint Disorders, Diagnostic studies and a ‘Yellow Light’ cautions us to be careful about surgery for TMJ (Throughout these articles, I will mainly use the more common abbreviation TMJ for this disorder).
References:
(1) NIH; NIDCR; Prevalence of TMJD and Its Signs and symptoms.
(2)Johansson A, et al; Gender difference in symptoms related to temporomandibular disorders. J Oro Facial Pain 2003.
(3) Forseth, K, GranT; Management of Fibromyalgia; 2002.
END Part 1