Migraine is frequently assumed to have an hereditary origin, but what this hereditary factor is, no one really knows. Researchers are currently trying to find defects in genes which could either cause, or tend towards, the development of migraine. This approach is deemed mistaken for two reasons: firstly, pain, being only a signal of an essential monitoring system, cannot be an inheritable factor on its own without the accompanying physiological or pathological processes which give rise to it; and secondly, physicians, almost universally, fail to examine a large part of the head, viz., the mandible and maxillae and their appendages, before making their diagnoses or providing treatment, thereby contravening the fundamental principle of properly examining patients. It is hereby suggested, and evidence is offered showing that impacted teeth could be the long sought-after `hereditary' factor causing migraine.