Temporomandibular Disorder (TMD): Symptoms and Treatment

The jaw joint is one of the hardest-working joints in the body; it moves constantly while we speak, chew and yawn. Pain and functional problems arising in this joint, or in the chewing muscles that move it, are grouped together under the heading of temporomandibular disorders (TMD). In this article we look at the symptoms, the underlying causes and the approaches used in treatment.

How the Jaw Joint Works

The end of the lower jawbone, called the condyle, sits in a hollow in the temporal bone just in front of the ear canal. A thin disc lies between the two bone surfaces and acts as a cushion. As the mouth opens, the condyle both rotates and slides forward, and the disc moves with it. Symptoms begin when the position of that disc is disturbed or when the muscles are overloaded.

What Are the Symptoms?

TMD does not present as a single picture. The most commonly reported complaints are:

• Pain in front of the ear, in the temple or along the jawline
• Clicking, popping or grating sounds when opening or closing the mouth
• Reduced mouth opening, and sometimes sudden locking
• Rapid fatigue while chewing, and tight jaw muscles in the morning
• Headache radiating from the temple, and tension in the neck and shoulders
• A feeling of fullness or ringing in the ear

Some of these findings can be mistaken for pain of dental origin. That is why the jaw joint belongs in the differential diagnosis when the causes of toothache are being assessed.

Causes

TMD complaints usually stem not from one cause but from several overlapping factors. Common contributors include clenching and grinding (bruxism), prolonged stress, trauma to the jaw, displacement of the joint disc, rheumatological joint disease and bite disorders. Missing teeth that have been left unreplaced for a long time can also contribute by distributing chewing load unevenly.

How Is It Assessed?

Assessment starts with a clinical examination: mouth opening is measured, joint sounds are listened for during opening and closing, and the chewing muscles and joint area are palpated. Wear facets, cracks and the bite relationship are examined. Radiographic imaging may be requested where needed, and more detailed imaging when the soft tissues have to be evaluated.

Treatment Approaches

Conservative measures

Treatment usually begins with reversible measures that do not alter tissue: avoiding hard, chewy foods for a period, not opening the mouth too wide, warm compresses, controlled jaw exercises and stress management. A considerable proportion of complaints can settle at this stage.

Night guard (occlusal splint)

Where clenching is part of the picture, a custom-made night guard is used to reduce the load carried by the chewing muscles and the joint. As well as protecting the teeth, the appliance can help muscle tension to ease.

Restoring worn teeth

Long-standing clenching may already have caused loss of tooth substance. Worn surfaces can be restored with treatments such as composite fillings; this step, however, is generally planned once the muscle and joint complaints have settled.

Pain management and further referral

Where indicated, your dentist may suggest medication, physiotherapy or referral to the relevant medical specialty. In selected cases where a structural problem inside the joint persists, further treatment options come into consideration.

When Should You Seek Care?

Assessment should not be postponed if mouth opening is markedly reduced, if the jaw locks in an open or closed position, if pain wakes you at night, if there is numbness in the face, or if complaints continue for weeks.

Summary

Temporomandibular disorders are a group of conditions marked by pain in the jaw joint and chewing muscles, joint sounds and restricted mouth opening. Clenching, trauma, the bite relationship and stress are frequent contributors. Treatment usually starts with reversible measures, a night guard and behavioural adjustments, and continues with restorative and further options where required.

This article is intended for general information purposes. A clinical examination is required to determine the right treatment plan for you.