Temporomandibular disorders (TMDs) are a set of musculoskeletal disorders affecting the temporomandibular joint (TMJ), the masticatory muscles, or both. TMDs comprise many diverse diagnoses with similar signs and symptoms affecting the masticatory system, which can be acute, recurrent, or chronic. TMDs are rarely life threatening, but can impact heavily on an individual's quality of life. Studies show that about 3–7% of the population need treatment.TMDs occur disproportionately in women of childbearing age in a ratio of 4:1 to 6:1, and the role of estrogens seems to show an association. The prevalence drops off dramatically for both men and women after age 55.