Guest Editorial: The Life-Threatening TMD

Editorial:

The term temporomandibular disorder (TMD) has gained wide acceptance and popularity and is often used as if it were a diagnosis. Conversely, it is a collective term embracing a number of clinical problems that involve the masticatory musculature, the temporomandibular joint (TMJ) , and its associated structures or both. Furthermore, TMD can also come to involve heterotopic symptomatology due to missed diagnosis or misdiagnosis. Because several pathological entities are collected under this umbrella term, adequate diagnosis is not duly made until the specific cause of the symptoms is identified. The use of TMD as a diagnosis might even put the patient's life at risk, should the TMD symptoms be caused by acute cardiac ischemia.1
The typical presentation of cardiac pain is reported in the left side of the chest, often radiating to the left arm and to the neck. Recent research has broadened the diagnostic spectrum of common symptoms by revealing that craniofacial pain can be expected in approximately 40% of patients during a cardiac ischemic event and can be the sole symptom in 6% of patients. Furthermore, in 2% it might be the sole symptom of acute myocardial infarction. The most common locations of craniofacial pain are the throat, left mandible, right mandible, temporomandibular joint/ear regions and teeth.
There is a growing awareness that a considerable number of patients develop acute myocardial infarction without experiencing any typical chest pain. New data show that in the absence of chest pain, the craniofacial area is the most prevalent location of pain, and it is three times more frequent than the left arm and four times more frequent than the stomach and the back. One in three patients with no chest pain during cardiac ischemia develops acute myocardial infarction, and these patients have a risk of life-threatening complications five times greater and a risk of death two to eight times greater than those patients with chest pain. During the last decade, an increasing awareness has also evolved regarding gender differences in the presentation of symptoms induced by cardiac ischemia. Women present with atypical symptoms more often than men, and a concordant observation is that craniofacial pain induced by cardiac ischemia is significantly more prevalent in women than in men.
A significant number of patients with atypical symptoms of acute coronary disease die before receiving appropriate hospital care due to failure to recognize the cardiac source of the symptoms. Patients with pain only in the head, face, TMJs or mouth are likely to seek treatment in a dental office or from a general practitioner. This increases the risk of treatment delay while therapy is directed to the pain site instead of the cardiac source. Approximately 1% of medical emergencies that occur in dental practice result in the patient's death and are mostly associated with acute cardiac failure. The estimated risk for a British dentist to encounter a patient death sometime during a 40-year career is calculated to be of the magnitude between 1:12 and 1:19.
Because patients who have acute myocardial infarction without chest pain run a higher risk of experiencing a missed diagnosis and death, the dentist's awareness of this symptomatology can be crucial for early diagnosis and timely treatment. It is therefore essential that the patient is not diagnosed with TMD but the underlying cause of the symptoms, i.e., the diagnosis, be obtained.
Another important undertaking is educating the public. In some countries, the public is well aware that chest pain and pain in the left arm is typical of cardiac ischemia. This implies the risk that a person with craniofacial pain as the sole symptom of acute cardiac disease will not seek emergency care because of the absence of chest and left arm pain. In the patient's mind, this means there is no cardiac problem.
A patient with suspected cardiac ischemia should be referred for examination primarily with a stress ECG. A patient with suspected acute myocardial infarction (AMI) should be sent to a hospital for emergency care.
The clinician should be alert and consider cardiac ischemia or AMI when there is no obvious local source of the craniofacial pain, particularly when combined with one or several of the following symptoms:
•    The pain is triggered by physical stress, e.g. walking up stairs, is of short duration and is spontaneously alleviated by rest. Cardiac ischemia should be considered;
•    The pain is persistent. AMI should be suspected;
•    Bilateral presentation. Referred pain from cardiac origin can be bilateral. Projected pain from dental origin seldom crosses the midline;
•    Female patients. Craniofacial pain as the sole symptom of cardiac ischemia or AMI is nearly 10 times more common in females than in males. Furthermore, females are more likely to present with atypical ECG registrations.
        Annika Isberg, D.D.S, Ph.D.
        University of Umeå

Reference:

1.    Kreiner M, Okeson J, Michelis V, Lujambio M, Isberg A: Craniofacial pain as the sole symptom of cardiac ischemia. A prospective multicenter study. J Am Dent Assoc 2007; 138:74-79.

Note: An upcoming study in the series focuses on A) the character of craniofacial pain, which was induced by cardiac ischemia or acute myocardial infarction, compared with B) the character of referred dental pain felt in the same regions. The results are aimed at further helping the clinician to determine the origin of craniofacial pain.