Validity of Clinical Examination for Diagnosing Clicking TMJ

Objectives: The aim of this study was to compare clinical examination for detecting internal derangements (IDs) in temporomandibular joints (TMJs) against magnetic resonance imaging (MRI) as the gold standard. Methods: Thirty two patients who were referred to the TMJ clinic at Damascus Dental School with at least one clicking TMJ participated in the study. Their 64 TMJs were clinically examined in a systematic way according to the classification of the American Association for Orofacial Pain. Clinical examination was made for every TMJ twice by one examiner with an interval of ten days and a diagnosis was determined as one of the following categories: no ID, disk displacement with reduction, disk displacement without reduction or degenerative joint disease. Modified sagittal MRI scans were performed for the 64 joints using GYROSCAN.ACS.NT.PHILIPS machine. Two experts in MRI, blinded to the clinical diagnosis, read the MRI scans independently and made a diagnosis for each TMJ as one of the above four categories. Kappa statistic was used to analyse agreement between the two clinical examinations, between the two MRI readings, and between the combined clinical and combined MRI examination. Sensitivity and specificity were also calculated for agreement between the clinical and MRI examinations. Results: Repeated clinical examination showed agreement on all but one TMJ. Similarly, the two radiologists agreed on the diagnosis of all but one TMJ. The agreement between the two clinical diagnoses and between the readings of the two radiologists was very high (98%). Moderate agreement was found between the clinical and MRI diagnoses (κ = 0.44 for both total group data for subgroups). Clinical examination showed high sensitivity (0.83) but fair specificity (0.60) against MRI. Conclusions: Clinical examination of TMJ can help in diagnosing ID but another tool like MRI may be needed for the final diagnosis.