Association of symptoms of TMD and orofacial pain with alexithymia: an epidemiological study of the Northern Finland 1966 Birth Cohort.

Alexithymia is a term denoting a deficit in the ability to differentiate emotional from physical states and to identify and describe one's feelings, as well as a preference for external oriented thinking. Alexithymia has been linked with various somatic and psychosomatic diseases, especially with chronic pain. The aim of this study was to evaluate the association between alexithymia and symptoms of temporomandibular disorders (TMD) as well as oro-lingual and dental pain, in a large representative population sample of young adults. The study was a part of the 31-year follow-up study of the Northern Finland Birth Cohort originally consisting of 12058 live births in the year 1966. In 1997, 4893 subjects living in northern Finland or in the capital area, who participated in a field study of the project and later returned a postal questionnaire, made up the sample of this study. Information concerning symptoms of TMD and oro-lingual and dental pain was collected from the subjects. To assess alexithymia, the Toronto Alexithymia Scale-20 (TAS-20) was used. In addition, information about depression, marital status and self-rated health was collected. The proportion of alexithymics (TAS score over 60) was higher in subjects with the most orofacial symptoms than in asymptomatic subjects. In men, alexithymia associated significantly with facial pain, difficulties in mouth opening, oro-lingual pain and dental pain, and in women with pain on jaw movement and dental pain. After adjusting for depression, marital status, and self-rated health, a significant association remained between alexithymia and the symptoms mentioned, except for facial pain in men. It can be concluded that alexithymia is connected with orofacial symptoms. Clinicians treating these symptoms should be familiar with the concept of alexithymia.