Diagnostic Value of Panoramic Radiographs in the Assessment of Degenerative Joint Disease: A Retrospective Study

Abstract

Introduction and Aims

This study evaluated the potential of panoramic radiographs (PR) for assessing temporomandibular joint (TMJ) osseous changes compared to Cone-beam Computed Tomography (CBCT). Our ultimate goal is to understand the value of PR as a screening tool and to get guidance for when CBCT should be requested for further investigation.

Methods

This cross-sectional retrospective study included patients 18 years or older with a PR and CBCT of TMJ from the School of Dentistry, University of Alberta, between 2021 and 2024. Exclusion criteria included poor image quality, an interval between PR and CBCT over 6 months, and TMJ not fully captured. Assessed findings from the images included condyle and articular eminence flattening, altered size, osteophyte formation, sclerosis, and erosion. Statistical analyses verified the diagnostic accuracy of PR in identifying TMJ degenerative findings compared to CBCT, the reference standard.

Results

One hundred and two TMJs from 51 patients (40 females and 11 males) were included in the study. PR sensitivity was below diagnostic thresholds recommended by current guidelines, ranging from 0 to 0.57, with only condyle flattening (0.55) and condyle altered shape/size (0.57), with a sensitivity above 0.50. A true negative was the most frequent score for all osseous findings except for flattening the condyle, with a high true positive in 32.25% of the cases. The specificity of PR ranged from 0.71 to 1.00.

Conclusion

PR is an opportunistic screening tool but does not meet sensitivity thresholds to serve as a stand-alone diagnostic method for TMJ DJD. Abnormal findings seen in the PR should prompt CBCT to confirm osseous pathology.

Clinical Relevance

PR is widely used in dental practice and may reveal gross TMJ abnormalities. When these findings align with clinical signs or symptoms, CBCT should be considered for further assessment. This approach supports earlier detection of DJD while adhering to the ALADAIP principle.