Headache is a common symptom, but when severe, it may be extremely disabling. It is assumed that patients who present to dentists with headache often are diagnosed with a temporomandibular disorder (TMD), although many may have migraine. TMD as a collective term may include several clinical entities, including myogenous and arthrogenous components. Because headache and TMD are so common they may be integrated or separate entities. Nevertheless, the temporomandibular joint (TMJ) and associated orofacial structures should be considered as triggering or perpetuating factors for migraine. This article discusses the relationship between the TMJ, muscles, or other orofacial structures and headache.