Jaw pain and dysfunction is a very common problem in the general population, affecting approximately 35% of people. Common signs and symptoms include jaw clicking, deviation on opening, and difficulty opening widely, but because of the proximity of the temporomandibular (TM) joint to the ear, pain, fullness of the ears and tinnitus can be also experienced.

Patients will frequently present to their family physician with complaints of ear pain for which no pathology is evident. Hearing difficulty may also be present, again with no obvious pathology. Repeated courses of antibiotics often don’t help and ENT examination usually shows nothing abnormal.

Morning headaches

Another common symptom related to jaw pain is frequent headache, usually occurring in the morning and affecting the temporal area bilaterally with pain across the back of the neck. When pain occurs later in the day, starting at the back of the neck and radiating to the forehead and behind the eyes, the root cause is much more commonly traced to the neck than to the jaw.

Although a third of the population have some signs and symptoms related to jaw pain, most don’t require treatment as their symptoms are transient. But patients who continue to experience chronic, intrusive symptoms do require investigation and treatment.

Clinical examination for the jaw includes palpation of the TM joints to determine if they’re painful. The range of vertical opening may be determined, with a normal range usually greater than 40 mm of opening between the central incisors. Excursions of the joints with opening can also demonstrate clicking, cracking or crepitus of the TM joints, which may hurt. Palpation of the masseter muscles on voluntary clenching can often help to determine if an individual may be clenching or grinding their teeth, especially when the masseters are very tight and associated with increased pain in the TM joint region.

Imaging options

If you suspect that the jaw may be contributing to headache, earache, or pain in the TM joints, this can be further investigated using a bone scan with tomographic cuts (SPECT) to look for evidence of inflammatory changes in one or both TM joints. MRI investigation of the joints is also very helpful, revealing evidence of disc changes as well as bony changes. The presence of inflammatory changes found on the bone scan is very useful in determining whether the joint is active and therefore likely contributing to an individual’s symptoms.

CT scan investigation of the TM joints is less helpful, since it doesn’t demonstrate the position and integrity of the disc. But it can be a valuable tool when the goal of imaging is to characterize discrete and significant bony changes, such as a jaw fracture.

Watch for symptoms on the ‘wrong’ side

At times, diagnosis can be confusing as the opposite joint will usually take on some of the work and strain normally borne by the joint that’s been injured. This causes the uninvolved joint to become symptomatic with complaints of both pain and clicking.

When it’s suspected that someone does have a jaw problem, consider referral to a dentist who’s knowledgeable about both diagnosis and treatment. Treatment often consists of a bite splint or occlusal appliance for grinding and clenching of the teeth — this is especially helpful for jaw clicking and headache pain. Use of medication including anti-inflammatories for an inflamed joint, and muscle relaxants for secondary tightness in the muscles of mastication can be helpful. Muscle relaxants can include medications such as Flexeril, Norflex and even gabapentin and amitriptyline. They should be taken before sleep to decrease parafunctional activity.

Tricky cases

At times, the MRI will demonstrate a disc displacement that isn’t reducing. In the acute phase, this can be associated with severe pain. These cases are best managed with therapeutic doses of anti-inflammatories as well as muscle relaxants, and with a short course of benzodiazepines. Referral to a dentist and/or a physiotherapist who is proficient at mobilizing the TM joints can be helpful. At times, the disc is not reducible but a trained physiotherapist can push the disc further anteriorly to decrease the mechanical restriction on the translation of the condylar head, and reduce inflammation within the joint space.

It’s usually unnecessary to pursue irreversible treatment such as changing the position of teeth, adjusting the bite or repositioning the jaw. Jaw pain is usually the result of either parafunctional activity or of an acute trauma to the head, such as may occur with a whiplash injury or direct impact to the joints themselves. It’s almost never the result of problems with the bite or with faulty jaw position.

Since the signs and symptoms related to the jaw are not always profound and often vary in presentation between patients, diagnosis with appropriate clinical examination and imaging prior to treatment is essential. It’s also key in determining when treatment is needed and which ones are optimal.

For more information, the American Academy of Orofacial Pain publishes guidelines for assessment, diagnosis and management of orofacial pain (fourth edition edited by R. de Leeuw) and can be accessed on their website at www.aaop.org .