180-degree CBCT Spin Protocol is Reliable in Detecting TMJ Arthritis

Objectives: To evaluate the diagnostic efficacy of two CBCT acquisition protocols to detect degenerative changes associated with the TMJ complex.
Methods: Thirty-four TMJs, from Seventeen dentate and partially dentate dry human skulls were obtained from the Anatomy Department at the UCONN School of Dental Medicine. Small and large lesions simulating early and established arthritic changes were created on the mandibular condyle on either the medial or lateral poles or the articulating surface. After simulating the articular disc with wax, the condyle and the glenoid fossa were articulated in the anatomical position. The skull was imaged using J.Morita’s Accuitomo CBCT scanner using a 180-degree and 360-degree spin protocol. Two operators scored the lesions and compared against the gold standard which was a master list of where the lesions were created.
Results: Of the 102 randomly simulated lesions, 39 were large and 33 were small lesions and the rest of the sites had no lesions. The detection rate for large lesions and areas with no lesions was 100% between both examiners. For small lesions, out of the 33 lesions each examiner identified 32lesions with the 360° scans, with a 97.4% detection rate. Using the 180 degree scan, 94.9% of small lesions were detected when compared to the gold standard and 96.9% detection rate compared to the 360° scan. The overall inter-examiner reliability was over 90% for both imaging protocols (Cronbach’s alpha for 180°: 92.4% and for 360°: 97%).
Conclusions: 180 degree CBCT acquisition protocol was able to detect small and large arthritic lesions with very high reliability and was comparable to a 360-degree CBCT spin acquisition.