Optimization analysis for plane orientation in 3-dimensional cephalometric analysis of serial cone-beam computerized tomography images

Objectives. The purpose of this study was to evaluate and reduce potential errors associated with superimposition of serial cone-beam computerized tomography (CBCT) images using planes based on cranial base landmarks. Methods. CBCTs from 10 patients were analyzed. The potential impact of errors in cranial base landmark identification on assessment of the relative position of distant landmarks is mitigated by means of a mathematical algorithm that ensures that the distances and angles between landmark identification points are maintained for different images by readjusting the landmark coordinates. Results. Significant improvement was observed after optimization. The errors found in a previous study were significantly reduced, some by more than 90%. Errors found in the standardization were viewed in both infraorbitals and mentons ranging from 1 to 3 mm. Conclusions. The mathematical transformation to readjust the coordinates of ELSA, left and right auditory external meatus (AEM), and dorsum foramen magnum (DFM) points significantly improves their use for image superimposition. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011; 111: 771-777)