Prevalence of temporomandibular joint internal derangement in patients with craniomandibular disorders.

To determine the prevalence of temporomandibular joint internal derangement in patients with signs and symptoms of craniomandibular disorders, bilateral imaging was performed in a consecutive series of 115 patients with signs and symptoms of craniomandibular disorders. Ninety patients (78%) had different stages of unilateral or bilateral internal derangement, and 25 patients (22%) had normal temporomandibular joints bilaterally. Out of 230 joints, 60 showed disk displacement with reduction, 8 showed disk displacement without reduction, and 29 showed disk displacement without reduction associated with anthrosis. The study indicates that almost 80% of patients with signs and symptoms of craniomandibular disorders have different forms of internal derangement.