TEMPOROMANDIBULAR-JOINT DISC POSITION IN ARTHROGRAPHY - A DESCRIPTIVE ANALYSIS OF THE OBSERVER PERFORMANCE

Objectives. To explore the relationship between the use of diagnostic cues and observer performance in the diagnosis of the temporomandibular joint (TMJ) disc position. Methods. Thirty arthrographic examinations using fluoroscopy alone and combined with either transcranial radiography or tomography were selected. Seven observers assessed the examinations with the aid of reference images and written diagnostic cues for three disc diagnoses. After one month three of the observers repeated the assessments and noted how they applied the diagnostic cues. Later, they made a consensus report on how the cues were applied to each joint. Results. The seven observers agreed unanimously with the reference diagnosis by fluoroscopy alone in 11 joints and in 14 when supplemented with transcranial radiography or tomography. Seven joints were given three different diagnoses by the seven observers when fluoroscopy was used alone and five when supplemented with transcranial radiography or tomography. The cues were applied with confidence in those joints where the observers were unanimous but in those with three different diagnoses, the anatomical features described in the cues were difficult to identify or the findings were ambiguous as they did not match the cues. Conclusions. It appears difficult to define radiographic cues applicable to all TMJ disc positions.