he purpose of this Funding Opportunity Announcement (FOA) is to stimulate research on discovering etiological and pathophysiological mechanisms underlying a set of chronic, comorbid conditions associated with temporomandibular joint and muscle disorders (TMJMDs). TMJMDs are a complex collection of diseases involving one or more tissues of the TMJ and facial musculature. Primary symptoms include chronic pain in facial muscles and limited and painful movement of the jaw. In addition, these and other symptoms of TMJMD can occur together with other chronic illnesses such as fibromyalgia, atypical face pain, trigeminal neuralgia, chronic fatigue syndrome, multiple chemical sensitivity, irritable bowel syndrome, complex regional pain syndrome, migraine headache, speech hearing, swallowing, balance, smell, and taste disorders, and certain cardiovascular diseases. This program announcement seeks research applications that use state-of-the-art, multidisciplinary and interdisciplinary approaches to discover molecular, physiological, and behavioral mechanisms responsible for the overlapping symptoms manifested in the set of disorders that may co-exist with TMJMD.