By definition this includes any joint problem that disrupts normal function. This is the most common diagnosis of TMJ dysfunction. Symptoms include clicking, locking, catching and grating with limitation of jaw opening. Patients often have difficulty eating and yawning due to pain. It can be quite debilitating in severe cases. Internal derangement is often due to inflammation within the joint capsule and can lead to "joint stickiness", a diseased disc and fibrotic changes which can all lead to severe breakdown of the joint itself - OSTEOARTHRITIS.
The above diagram demonstrates a simplistic explanation of a displaced disc (which clicks) within the joint. The disc acts as a shock absorber and load distributor and can deteriorate with long standing injury and inflammation.
Treatments vary from arthroscopic procedures to total joint replacements. It is usually recommended that non-surgical treatments are used concurrently such as intra-oral appliances and analgesics when needed.