Temporomandibular disorders and hormones in women

Temporomandibular disorders (TMD) are loosely defined as an assorted set of clinical conditions, characterized by pain and dysfunction of the masticatory system. Pain in the masticatory muscles, in the temporomandibular joint (TMJ), and in associated hard and soft tissues, limitation in jaw function, and sounds in the TMJ are common symptoms. That women make up the majority of patients treated for TMD is extensively hypothesized and documented in numerous epidemiological studies. Certain contradictory studies exist which propose that there are no statistically significant gender differences in the actual incidence of changes in joint morphology. Nonetheless, extensive literature suggests the disorder is 1.5-2 times more prevalent in women than in men, and that 80% of patients treated for TMD are women. The severity of symptoms is also related to the age of the patients. Pain onset tends to occur after puberty, and peaks in the reproductive years, with the highest prevalence occurring in women aged 20-40, and the lowest among children, adolescents, and the elderly. The gender and age distribution of TMD suggests a possible link between its pathogenesis and the female hormonal axis. In this review, we will use the hypothesis that the overwhelming majority of patients treated for temporomandibular disorders are women and use the available literature to examine the role of hormones in TMD.