The document discusses temporomandibular joint disorders (TMD), which refers to any problem involving the jaw joint. TMD is most common in people ages 20-40 and affects females more than males. Common TMD disorders include pain, dysfunction, internal derangement, and arthritis. Disc displacement, a disorder where the articular disc has an abnormal relationship with the mandibular condyle, is classified anatomically and functionally. Diagnosis involves clinical evaluation, history, and physical examination. Management depends on severity and can include self care, physical therapy, splinting, medications, injections, and surgeries such as arthrocentesis, arthroscopy, or joint replacement.