This article describes the biomechanical and physiologic processes occurring with the insidious development of craniomandibular dysfunction. This explanation uses basic orthopedic concepts and correlates the specific pathophysiologic circumstances that result in internal derangements and adhesive capsulitis. The specific pathophysiologic processes reviewed here include collagen failure, inflammatory response, synovitis, synovial hypertrophy, fibrous adhesion formation, and chondromalacia degenerative changes. Current diagnostic terminology describes internal derangements as being present with or without reduction. In view of the physiologic processes described, a better diagnostic description would be internal derangment with adhesion. Treatment should be directed toward preventing progression of degenerative changes and allowing normal reparative processes to proceed.