Toothache referred from heart disease and lung cancer via the vagus nerve.

New epidemiologic evidence suggests that referred craniofacial pain in coronary heart disease is more common than previously believed. Current medical reports suggest that in addition to coronary disease, thoracic disorders such as aortic dissection, pericarditis, and lung cancer can cause referred craniofacial pain. Recent physiologic evidence from animals and humans suggests that the vagus nerve mediates this referral of cardiac pain to the maxillofacial region. This article discusses the critical role of the dentist in patient education and recognition of referred head and neck pain in thoracic disease, in relation to the need for prompt medical treatment for these life-threatening conditions.