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Juan Wen Shu Liu Xiao Ye Xiaoqiu Xie Jialing Li Huang Li Li Mei 《Journal of the American Dental Association (1939)》2017,148(12):913-921
Background
The authors conducted a study to compare 2-dimensional (2D) lateral cephalometric radiography (LCR), 2D cone-beam computer tomographic (CBCT)–generated cephalogram and 3-dimensional (3D) CBCT for assessing cephalometric measurements.Methods
The authors took 2D LCR, 2D CBCT-generated cephalogram, and 3D CBCT images involving 60 participants. They obtained 11 angular and 11 linear measurements for all images. They used 1-way analysis of variance and the Fisher least significant difference test for statistical comparisons. The authors used Pearson correlation and Pearson χ2 test to assess the relationship of these imaging modalities for vertical cephalometric analyses.Results
Significant differences existed between the 2D cephalograms (LCR and CBCT-generated cephalogram) and the 3D CBCT in 2 angular measurements (maxillary first incisor-nasion (N) point A [A] and mandibular first incisor-N point B (B) (P = .027 and P < .001, respectively) and 5 linear measurements (N menton[Me]/sella gonion [Go], condylion [Co]A, Co gnathion, Go-Me and anterior nasal spine-posterior nasal spine) (P < .004). These measurement values with significant differences were generally greater (approximately 5° for angular measurements and 10 millimeters for linear measurements) on the 3D CBCT scans than on the 2D cephalograms. No significant difference was found between the 2 2D cephalograms (P > .164). No significant difference was found among the 3 imaging modalities for the vertical cephalometric analyses (P > .466).Conclusions
Significant differences existed between the 2D cephalograms (LCR and CBCT-generated cephalogram) and the 3D CBCT scans in 2 angular and 5 linear measurements. The 2 2D cephalograms were similar for cephalometric measurements. The 3 imaging modalities had no significant difference for the vertical cephalometric analyses. CBCT might not add value for every orthodontic situation.Practical Implications
These results find the values of cephalometric measurements on 3D CBCT scans may be greater than on the conventional LCR for some parameters. The 2D CBCT-generated cephalogram could be an alternative to the conventional LCR for patients whose large-field-of-view CBCT images are already available. 相似文献3.
The mandible is the single mobile bone of the skull. It develops from the sixth week of the intrauterine life. The aim of our study is to confirm the variability of different mandibular landmarks in humans of different geographic areas. A number of 100 young persons from different geographic areas (Europe, Middle Orient, Asia and Africa) were selected. We used the classical measurement with the metric band and Baudeloque compass and analysed 50 cephalograms in frontal and lateral views. The focus of our measurements were the opening of the mandibular angle (gonion), ramal length and width, condylar diameters and the gonion–menton distance. In the European specimens, the opening of the mandibular angle is smaller than in the Asians. Africans had a lower value of the mandibular angle than Asians. Significant differences appeared in the gonion–menton distance measurements, as well. In conclusion, there is a positive correlation between the mandibular angle and the menton–gonion distance, respectively. 相似文献
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