Symptoms of internal derangement
Disk derangement with reduction often causes a painless clicking or popping sound when the mouth is opened. Pain may be present, particularly when chewing hard foods. Patients are often embarrassed because they think others can hear noise when they chew. Indeed, although the sound seems louder to the patient, others can sometimes hear it. Disk derangement without reduction usually causes no sound, but maximum opening between the upper and lower incisors is reduced. Pain and a change in the patients' perception of their bite generally result. It usually manifests acutely in a patient with a chronically clicking joint; about 8 to 9% of the time, the patient awakens unable to open the jaw fully. In a small percentage of patients, the symptoms of disk derangement without reduction spontaneously resolve after 6 to 12 months. Capsulitis results in localized joint pain, tenderness, and, sometimes, restricted opening.