4.01 Temporomandibular Joint (TMJ) Pain-Dysfunction Syndrome

agk’s Library of Common Simple Emergencies

Presentation

Patients usually complain of poorly-localized facial pain or headache that does not appear to conform to a strict anatomical distribution. The pain is generally dull and unilateral, centered in the temple, above and behind the eye, in and around the ear. The pain may be associated with instability of the temporomandibular joint (TMJ), crepitus, or clicking with movement of the jaw. It is often described as an earache. Other less obvious symptoms include radiation of pain down the carotic sheath, tinnitus, dizziness, decreased hearing, itching, sinus symptoms, a foreign body sensation in the external ear canal, trigenimal, occipital and glossopharyngeal neuralgias. Patients may have been previously diagnosed as suffering from migraine headaches, sinusitis or recurrent external otitis. Predisposing factors include malocclusion, recent extensive dental work, or a habit of grinding the teeth (bruxism), all of which put unusual stress upon the TM joint. Clinical signs include tenderness of the chewing muscles, the ear canal or the joint itself, restricted opening of the jaw or lateral deviation on opening, and a normal neurological examination.

What to do:

• Examine the head thoroughly for other causes of the pain, including visual acuity, cranial nerves, and palpation of the scalp muscles and the temporal arteries. Pain and popping on moving the TMJ is a useful but not infallible sign. Look for signs of bruxism, such as ground-down teeth. If there is a headache, perform a complete neurologic examination, including fundoscopy. If the temporal artery is tender, swollen or inflamed, send blood for an erythrocyte sedimentation rate.
• If pain is severe, you may try injecting the TMJ, just anterior to the tragus, with l ml of plain lidocaine or bupivicaine, along with 10mg of DepoMedrol. If this helps, you may have made the diagnosis, and possibly provided long-term relief.
• Explain to the patient the pathophysiology of the syndrome: how many different symptoms may be produced by inflammation at one joint, how TMJ pain is not necessarily related to arthritis at other joints, and how common it is (some estimates are as high as 20% of the population).
• Prescribe anti-inflammatory analgesics (e.g., aspirin, ibuprofen, naproxen), a soft diet, heat, and muscle relaxants (e.g., diazepam) if necessary for muscle spasm.
• Refer the patient for followup to a dentist or otolaryngologist who has some interest in and experience with TMJ problems. Long-term treatments include orthodontic correction, physical therapy and sometimes psycho- therapy and antidepressants.

What not to do:

• Do not rule out TMJ arthritis simply because the joint is not tender on your examination. This syndrome typically fluctuates, and the diagnosis often is made on history alone.
• Do not omit the TMJ in your workup of any headache.
• Do not give narcotics unless there is going to be early follow up.

Discussion

The relative etiologic roles of inadequate dentition, unsatisfactory occlusion, dysfunction of the masticatory muscles and emotional disorders remain controversial. To stress the role played by muscles, it has been suggested that the term “myofascial pain-dysfunction (MPD) syndrome is more accurate than”TMJ arthritis." There is also much debate as to the indications for and the efficacy of treatment modalities aimed at the presumed etiologies. At the least, irreversible treatments such as surgery should be replaced by more conservative therapy. The use of bite blocks for bruxism was based on outdated information and may only serve to alter normal dental occlusion with deleterious effects.

Perhaps everyone suffers pain in the TMJ occasionally, and only a few require treatment or modification of lifestyle to reduce symptoms. In the ED the diagnosis of TMJ pain is often suspected, but seldom made definitively. It can be gratifying, however, to see patients with a myriad of seemingly unrelated symptoms respond dramatically after only conservative measures and advice.

References:

• Guralnick W, Kaban LB, Merrill RG: Temperomandibular joint afflictions. N Eng J Med 1978:299:123-128.

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