Zhenqi Zhao1,2,3, Lizhe Xie1,4, Dan Cao1,3, Iman Izadikhah1,3, Pengcheng Gao5, Yang Zhao6, Bin Yan1,3. 1. Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China. 2. Department of Stomatology, The First People's Hospital of Nantong, Nantong, China. 3. Department of Orthodontics, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China. 4. Engineering center for digital medical technology of stomatology, Nanjing Medical University, Nanjing, China. 5. Department of Orthodontics, Zhongda hospital, Southeast university, Nanjing, China. 6. School of Public Health, Nanjing Medical University, Nanjing, China.
Abstract
OBJECTIVES: This study was aimed to investigate the accuracy of soft-tissue measurements obtained by two imaging modalities, three-dimensional (3D) photogrammetry and cone beam CT (CBCT) when confounded by influence factors (facial deformities and partitions). METHODS: 60 wax facial models from facially deformed patients were captured by 3D photogrammetry and CBCT. 19 linear distances on each image were measured and juxtaposed to reference values attained via a coordinate-measuring machine (CMM) as the gold-standard. Paired t-tests were used to compare linear accuracy of the test and reference systems. The influence of deformities and partitions (created by dividing the face with three vertical and five horizontal lines) on the measurement errors were analyzed by independent sample t-test and one-way ANOVA. RESULTS: Statistically significant differences were found between linear accuracy of the test and reference systems. The test values obtained by 3D photogrammetry were closer to the reference values than CBCT's. 3D photogrammetry's measurement errors were significantly higher in deformed areas, unlike CBCT's. Both systems reported significantly lower errors within partitions 8 and 13 compared to other partitions; for CBCT, aside from partitions 8 and 13, the differences in the errors for partitions 6 and 10 were significant compared to partitions 8, 12, 13, 14. CONCLUSION: 3D photogrammetry showed a higher linear accuracy than CBCT in patients with facial deformities due to protuberances. Facial reconstruction by both test modalities was significantly influenced in different facial partitions, but facial deformities extensively affected the results from 3D photogrammetry.
OBJECTIVES: This study was aimed to investigate the accuracy of soft-tissue measurements obtained by two imaging modalities, three-dimensional (3D) photogrammetry and cone beam CT (CBCT) when confounded by influence factors (facial deformities and partitions). METHODS: 60 wax facial models from facially deformed patients were captured by 3D photogrammetry and CBCT. 19 linear distances on each image were measured and juxtaposed to reference values attained via a coordinate-measuring machine (CMM) as the gold-standard. Paired t-tests were used to compare linear accuracy of the test and reference systems. The influence of deformities and partitions (created by dividing the face with three vertical and five horizontal lines) on the measurement errors were analyzed by independent sample t-test and one-way ANOVA. RESULTS: Statistically significant differences were found between linear accuracy of the test and reference systems. The test values obtained by 3D photogrammetry were closer to the reference values than CBCT's. 3D photogrammetry's measurement errors were significantly higher in deformed areas, unlike CBCT's. Both systems reported significantly lower errors within partitions 8 and 13 compared to other partitions; for CBCT, aside from partitions 8 and 13, the differences in the errors for partitions 6 and 10 were significant compared to partitions 8, 12, 13, 14. CONCLUSION: 3D photogrammetry showed a higher linear accuracy than CBCT in patients with facial deformities due to protuberances. Facial reconstruction by both test modalities was significantly influenced in different facial partitions, but facial deformities extensively affected the results from 3D photogrammetry.
Entities:
Keywords:
3D imaging; 3D photogrammetry; Cone-beam Computed Tomography; Facial deformities; Linear accuracy
Authors: Bernard A M M L Moerenhout; Frederik Gelaude; Gwen R J Swennen; Jan W Casselman; Jos Van Der Sloten; Maurice Y Mommaerts Journal: J Craniomaxillofac Surg Date: 2008-09-23 Impact factor: 2.078
Authors: Maria de Paula Caldas; Flávia Maria de Moraes Ramos-Perez; Solange Maria de Almeida; Francisco Haiter-Neto Journal: J Appl Oral Sci Date: 2010 May-Jun Impact factor: 2.698