MRI evaluation of TMJ internal derangement: Degree of anterior disc displacement correlated with other TMJ soft tissue and osseous abnormalities

ObjectiveTo evaluate the relationship between anterior disc displacement (ADD) degree and other temporomandibular joint (TMJ) soft tissues and osseous abnormalities in symptomatic TMJ dysfunction based on magnetic resonance imaging findings.Patients and methodsMR images of 106 TMJs in 53 patients, presented with symptomatic TMJ dysfunction were included. Degree of ADD was detected and its relationship to joint effusion, retrodiscal layer integrity, thickness of lateral pterygoid muscle (LPM) attachments, degenerative changes and condylar position and translation as well as clinical manifestations was studied.ResultsCompared with normal disc position, risk of joint effusion and degenerative changes were significantly increased with increased degree of ADD (p < 0.05). LPM attachment thickening and retrodiscal layer abnormalities are significantly associated with an advanced degree of ADD (p < 0.05). Risk of ADD is significantly increased with posterior position of the condyle within the fossa.ConclusionThere is a direct relationship between the ADD degree and other TMJ soft tissues and bone abnormalities as well as the severity of clinical manifestations, so early MRI detection and reporting of ADD degree and other MRI findings might help clinicians in full assessment and determining strategy of management of TMJ dysfunction.