Sagital TMJ disc changes over time: A retrospective study

Objectives: As part of the Temporomandibular Disorders (TMD) family, temporomandibular joint (TMJ) disc displacement is a mechanical condition in which the articular disc does not present a normal contact with the articular surfaces due to a change in its position. Magnetic resonance imaging (MRI) is a valid and reliable method to identify TMJ disc displacement. Although it is commonly assumed that TMJ disc displacement progresses with time, there are no MRI retrospective studies evaluating sagital changes of the disc from a normal to a non-physiological position or the progression of such condition over time. The clinician often faces questions from patients who ask if their condition would get more severe over time. The aim of this retrospective study was to provide such answer, and if any, to evaluate what clinical and demographic factors were associated with such problem. Methods: TMJ MRIs from a sample of 94 adolescent patients were obtained at two different points is time separated by 4 years. Articular disc position was measured at both times and statistically compared for sagital changes with respect to the condyle and articular eminence. Results: No clear evidence was found to suggest that disc displacement progresses over time in adolescents. Factors such as pain upon palpation, pain upon jaw opening, chronic closed lock, TMJ click, age, gender and history of facial trauma did not present a clear correlation with the amount of disc displacement. Conclusions: the clinician should be aware that although progression of TMJ disc displacement over time might be a possibility, there is no definitive evidence on this matter. Patients must be instructed to follow conservative treatment and should also be informed what current research is indicating in this regard.