A biplanar cephalometric stereoradiography technique.

A biplanar cephalometric stereoradiography (BCSR) technique was developed for accurate three-dimensional assessment of structures that can be identified by markers or anatomical landmarks that are visible on both lateral closed and posteroanterior cephalometric radiographs. The accuracy and precision of the technique were determined by means of a phantom and clinical radiographs. On the phantom, three-dimensional coordinates were determined by the BCSR technique and were measured directly with an electronic digital caliper. The accuracy of the BCSR technique was found to be within 0.5% of the measured distances. On clinical radiographs, the lengths of plates and screws, used as rigid fixation devices, were measured on two subsequent sets of biplanar radiographs and were found to be within the accuracy of our current digitizer (+/- 0.381 mm). The stability of interosseous wires was tested against implants and other interosseous wires on two subsequent sets of biplanar radiographs through a comparison of the distances between two devices. These comparisons confirmed the stability of interosseous wires. The BCSR technique proved to be an accurate method for measurements in three dimensions.