Comparison of three radiographic methods for detection of morphological temporomandibular joint changes: panoramic, scanographic and tomographic examination.

OBJECTIVES

To compare the diagnostic accuracy of panoramic, scano- and tomographic examination for the detection of morphological temporomandibular joint (TMJ) changes.

METHODS

TMJs in 80 dry human skulls were radiographed using digital panoramic examination, 4x sagittal (lateral) scanography, and sagittal cross-sectional tomography. All images were examined by three independent observers for the presence or absence of flattening, defects and osteophytes in the various joint components. The true presence of the morphological changes was unanimously decided by consensus of three independent observers using naked-eye inspection. The accuracy for detection of the specific changes in each joint component was expressed as sensitivity and specificity values, whereas the accuracy for detection of morphological changes in general in the condyle and in the TMJ in toto was expressed as the number of matching radiographic and "gold standard" scores.

RESULTS

Up to 23% and 9% of the three joint components were recorded as non-accessible to examination with panoramic examination and sagittal (lateral) scanography, respectively, whereas all components were accessible to examination with sagittal cross-sectional tomography. The difference was significant between panoramic examination and sagittal cross-sectional tomography (P = 0.018). No significant differences between the three methods for detection of specific morphological changes in the condyles and defects in the articular tubercles and changes in the TMJ in toto were found.

CONCLUSION

No differences in accuracies between the methods were found for the detection of morphological TMJ changes. However, with panoramic examination and sagittal (lateral) scanography markedly more joint components were non-accessible to examination than with sagittal cross-sectional tomography, with which all components were accessible.