Validity of three-dimensional computed tomography measurements for Le Fort I osteotomy.

The purpose of this study was to test the precision and accuracy of three-dimensional (3D) linear measurements for Le Fort I osteotomy, obtained from multi-slice computed tomography (MSCT) and cone beam computed tomography (CBCT) scans. The study population consisted of 11 dried skulls submitted to 64-row MSCT and CBCT scans. Three-dimensional reconstructed images (3D-CT) were generated, and linear measurements (n=11) based on anatomical structures and landmarks of interest for Le Fort I osteotomy were performed independently by two oral and maxillofacial radiologists, twice each, using Vitrea software; this allows true 3D measurement on 3D-CT images. The results demonstrated no statistically significant differences between the inter-examiner and intra-examiner analyses, and physical and true 3D linear measurements using MSCT and CBCT images. Regarding examiner accuracy, no statistically significant differences were found for the comparisons among the physical and the MSCT and the CBCT linear measurements by either examiner. For examiners 1 and 2, the analysis intra-examiner correlation coefficient ranged from 0.87 to 0.96 and 0.82 to 0.98, respectively, using MSCT, and from 0.84 to 0.98 and 0.80 to 0.98, respectively, using CBCT, indicating almost perfect agreement for all analyses performed. 3D linear measurements obtained from MSCT and CBCT images were considered precise and accurate for Le Fort I osteotomy and thus accurate and helpful for Le Fort I osteotomy planning.