Temporomandibular disorders and migraine chronification.

Among the established and potential comorbidities of migraine, the temporomandibular disorders (TMD) are rarely discussed, although they are of importance for several reasons. TMD may cause headaches per se, worsen existent primary headaches, and add to the burden of headache disorders. This article explores the potential comorbidity between migraine and TMD and the role of TMD as a potential factor to induce chronic migraine. We discuss the similarities between both conditions, review evidence to support the idea that both disorders are comorbid, and highlight the limited evidence suggesting that TMD influence migraine progression. Finally, we discuss the importance of cutaneous allodynia mediating the TMD/frequent headache relationship.