Four health outcomes (range of motion, pain, diet, and disability) were measured in six diagnostic categories (internal derangement with closed lock, internal derangement with painful click, osteoarthritis, hypermobility, fibrous ankylosis, and arthralgia) in a 6-year retrospective multicenter study of 4,831 temporomandibular joints having undergone arthroscopic surgery. After arthroscopic surgery, 91.6% of all patients had good or excellent motion; 91.3% had good or excellent pain reduction; 90.6% had good or excellent ability to maintain a normal diet; and 92% had a good or excellent reduction in disability. These health outcomes compare favorably with all other known treatments for these conditions. Also, the surgical technique was relatively free of complications (4.4%).