The clinical signs and symptoms of greatest semiologic value in temporomandibular joint disease (TMJD) are muscle pain, joint pain, limitations in mandibular movement, and joint sounds. Imaging studies of the joint are very useful for establishing the diagnosis and for discarding other disease processes, though in many cases diagnostic error results from the detection of a large proportion of patients with alterations in the imaging studies but with no associated clinical manifestations. Panoramic X-rays and magnetic resonance imaging are the most commonly used complementary techniques for diagnosing TMJD. MRI may be regarded as the imaging technique of choice, particularly when studying the soft tissues. Biochemical evaluation of the joint synovial fluid has improved our understanding of TMJD pathogenesis, though to date such parameters have not been extended to clinical practice. Myofascial pain with positive painful palpation of the masticatory muscles; joint disc displacements with reduction characterized by the presence of opening or opening and closing clicks; disc displacements without reduction characterized by limitations in oral aperture; and osteoarthritis / osteoarthrosis characterized by the auscultation of friction sounds during mandibular movement, are the morbidity processes most often seen in the context of TMJD. The present study offers a review of the semiology and morbidity processes of the temporomandibular joint.