Perceptibility of condylar displacement through transcranial radiographs and split-cast technique on dry skull

The authors compared the limit of perceptibility of transcranial radiographs and of the split-cast technique in detecting differences in condylar position. The study was carried out on two dried human skulls. The results indicated the split-cast method was superior to the radiographic method as it allowed differences in condylar position of 0.2 mm, both in sagittal and frontal plane, to be detected. The limit of perceptibility of transcranial radiographs for position differences in the sagittal plane was 0.6 mm for naked-eye examination and 0.2 mm when using the subtraction method. Differences in condylar position even as large as 0.6 mm in the frontal plane could not clearly be seen by naked-eye examination, and with the subtraction technique only if they were of at least 0.4 mm.