Diagnostic accuracy of fused CBCT images in the evaluation of temporomandibular joint condylar bone resorption

Abstract

Objectives: To evaluate the diagnostic accuracy of fused CBCT images for patients with condylar bone resorption of temporomandibular joint (TMJ) osteoarthrosis.

Materials and methods: Forty-two TMJs from twenty-one patients were included. Bone resorption of condyles evaluated by three experts was used as the reference standard. Three oral and maxillofacial radiology residents evaluated the resorption of condyles with a five-point scale for the four sets of images (two consecutive CBCT images without fusion, fused 2D cross-sectional images, fused 3D images, and combining fused 2D cross-sectional images and fused 3D images) randomly and independently. Each set of images was evaluated at least 1 week apart, and a second evaluation was performed 4 weeks later. Intraclass correlation coefficients were calculated to assess the intra- and inter-observer agreement. The areas under the ROC curves (AUCs) were compared among the four image sets using the Z test.

Results: Twenty-four TMJs were determined as condylar bone resorption, and eighteen were determined as no obvious change. The average AUC values from the three observers for the three fused image sets (0.94, 0.93, 0.93) were significantly higher than the image set without fusion (p < 0.01). The intra- and inter-observer agreement on the three fused image sets (0.70-0.89, 0.91-0.92) was higher than the image set without fusion (0.37-0.63, 0.75).

Conclusions: Fused CBCT images of TMJ osteoarthrosis patients can intuitively display the condylar bone resorption and significantly improve the diagnostic accuracy.

Clinical relevance: Fused CBCT images can help clinicians intuitively observe bone changes of the condyle in TMJ osteoarthrosis patients.

Keywords: Cone-beam computed tomography; Diagnosis; Registration; Temporomandibular joint.