scholarly journals In Vivo Comparison of Conventional and Cone Beam CT Synthesized Cephalograms

2008 ◽  
Vol 78 (5) ◽  
pp. 873-879 ◽  
Author(s):  
Vandana Kumar ◽  
John Ludlow ◽  
Lucia Helena Soares Cevidanes ◽  
André Mol
Keyword(s):  
Repeated Measures ◽  
Cone Beam Ct ◽  
Statistical Significance ◽  
Three Dimensional ◽  
Cone Beam ◽  
Volume Data ◽  
Linear Measurements ◽  
Lateral Cephalograms ◽  
Angular Measurements

Abstract Objective: To compare measurements from synthesized cone-beam computed tomography (CBCT) lateral cephalograms using orthogonal and perspective projections with those from conventional cephalometric radiographs. Materials and Methods: Thirty-one patients were imaged using CBCT and conventional cephalometry. CBCT volume data were imported in Dolphin 3D. Orthogonal and perspective lateral cephalometric radiographs were created from three-dimensional (3D) virtual models. Twelve linear and five angular measurements were made on synthesized and conventional cephalograms in a randomized fashion. Conventional image measurements were corrected for known magnification. Linear and angular measurements were compared between image modalities using repeated measures analysis of variance. Statistical significance was defined as an α level of .01. Results: With the exception of the Frankfort-mandibular plane angle (P < .0001), angular measurements were not statistically different for any modality (P > .01). Linear measurements, whether based on soft or hard tissue landmarks, were not statistically different (P > .01). Conclusions: Measurements from in vivo CBCT synthesized cephalograms are similar to those based on conventional radiographic images. Thus, additional conventional imaging may generally be avoided when CBCT scans are acquired for orthodontic diagnosis.

scholarly journals Taurodontism and Van der Woude Syndrome

2008 ◽  
Vol 78 (5) ◽  
pp. 832-837 ◽  
Author(s):  
Hiroyuki Nawa ◽  
Snehlata Oberoi ◽  
Karin Vargervik
Keyword(s):  
Clinical Sample ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Panoramic Radiograph ◽  
Cross Sectional Study ◽  
Cone Beam ◽  
Linear Measurements ◽  
Van Der Woude Syndrome ◽  
Cross Sectional ◽  
Mandibular First Molar

Abstract Objective: To report the occurrence of taurodontism in a clinical sample of Van der Woude syndrome (VWS) and describe its association with hypodontia and cleft type. Materials and Methods: This retrospective, cross-sectional study was carried out on chart reviews and radiographs of 13 persons with VWS. Mean age was 10 years 11 months ± 1 year 5 months. Panoramic radiographs were used to confirm the presence or absence of teeth and to measure crown body and root lengths of mandibular first molars. Three-dimensional cone beam computed tomography (CT) scans were available on two persons with VWS. Both volumetric and linear measurements were obtained. Results: The occurrence of taurodontism of the mandibular first molar was 35%: 27% hypodont and 8% mesodont. Of the 13 subjects with VWS, 6 (4 males and 2 females) had at least one tooth identified with taurodontism. Half of the cases were unilateral and half were bilateral, and all of the unilateral cases were on the left side. Five of the six subjects with taurodontism had missing incisors and premolars. Taurodontism was two times more frequent in those who were missing their second premolars than in those who had their second premolars. There was no correlation between cleft type and presence of taurodontism. The cone beam CT pilot study on two persons showed very abnormal morphology of both crown and roots, which was not apparent on the standard panoramic radiograph. Both the volumetric and linear measurements of the ratio of crown body to root were highly indicative of taurodontism. Further genetic studies are needed. Conclusion: There is a likely association between VWS and taurodontism.

Tooth and root size as determined from 0.25- and 0.30-mm voxel size cone-beam CT imaging when contrasted to micro-CT scans (0.06 mm): An ex vivo study

2021 ◽  
pp. 146531252110661
Author(s):  
Gaston F Coutsiers Morell ◽  
Yuli Berlin-Broner ◽  
Carlos Flores-Mir ◽  
Giseon Heo
Keyword(s):  
Repeated Measures ◽  
Root Resorption ◽  
Ex Vivo ◽  
Imaging Modality ◽  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam ◽  
Micro Ct ◽  
Voxel Size ◽  
Ex Vivo Study

Objective: To quantify tooth volume differences from extracted teeth when using three different three-dimensional (3D) computed tomography (CT)-based imaging modalities. Design: Ex vivo study. Setting: Laboratory and clinics of the University of Alberta. Methods: Cone-beam CT (CBCT) of 12 extracted teeth were scanned using 0.25- and 0.30-mm voxel size from CBCT and a 0.06-mm voxel size from micro-CT (reference standard). 3D reconstructions for each tooth from each imaging modality were made through the software ITK-SNAP®. The mean volume differences between each pair of scanning modalities were calculated and then compared and analysed through a repeated measures ANOVA. Results: The average overestimations of the teeth volume were 15.2% for the high-resolution CBCT and 28.1% for the low-resolution CBCT compared to micro-CT measurements. The differences in absolute volume were 81.6 mm3 and 152.8 mm3, respectively. All differences were statistically significant ( P < 0.05). Conclusions: Orthodontists and researchers who assess root resorption through CBCT imaging should be aware that the depicted volumes may likely be overestimating tooth volume and camouflaging real root volumetric treatment changes.

910 Automatic Determination Technique of Three-Dimensional Tooth Axis Using In Vivo Cone-Beam CT Images

2016 ◽  
Vol 2016.53 (0) ◽  
pp. _910-1_-_910-3_
Author(s):  
Makoto SAKAMOTO ◽  
Yusuke MORISE ◽  
Koichi KOBAYASHI ◽  
Takashi KAMEDA ◽  
Sachiko HAYASHI-SAKAI ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Three Dimensional ◽  
Ct Images ◽  
Cone Beam ◽  
Automatic Determination ◽  
Tooth Axis

Automatic Three-Dimensional Tooth Axis Using In Vivo Cone-Beam CT Images

2016 ◽  
Vol 2016 (0) ◽  
pp. S0220202
Author(s):  
Makoto SAKAMOTO ◽  
Yusuke MORISE ◽  
Koichi KOBAYASHI ◽  
Takashi KAMEDA ◽  
Sachiko HAYASHI-SAKAI ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Three Dimensional ◽  
Ct Images ◽  
Cone Beam ◽  
Tooth Axis

scholarly journals Accuracy of Models Obtained from Digital Impressions Versus Scanning of Conventional Impressions

2021 ◽  
Author(s):  
Noha M. Elkersh ◽  
Rania A.Fahmy ◽  
Mohamed K. Zayet ◽  
Yousria S. Gaweesh
Keyword(s):  
Repeated Measures ◽  
Laser Scanning ◽  
Visual Analysis ◽  
Three Dimensional ◽  
Digital Model ◽  
Linear Measurements ◽  
Deviation Analysis ◽  
Digital Impressions ◽  
Mean Differences

Abstract Background Digital workflow has invaded the different dental specialities. It includes some steps, the first of them is the scan process and dental modelling. Many methods are available for digital model fabrication. Therefore, the aim of this in vivo study to assess and compare the accuracy of 3-dimensional (3D) digital dental models obtained from scanning of conventional impressions versus models from digital impressions. Materials and Methods Three-dimensional digital model files were obtained in vivo from three different methods including scanning of impressions by both Cone beam computed tomography (CBCT) machine (Veraview x800, JMorita) and desktop scanner (Smart optics, Vinyl Open Air). The same volunteers have received digital impressions by an intraoral scanner (CS3600). Six linear measurements were measured in each Stereolithography (STL) model and compared with direct calliper measurements. Additionally, STL files from the three systems were paired and superimposed using a best-fit algorithm in a 3D modelling software. Mean deviations between the STL shells were calculated by the software and color maps were obtained for visual analysis. Intra-class correlation coefficient (ICC) was calculated to determine the intra-examiner reliability. Paired t-test, ANOVA with repeated measures and Post Hoc test (Bonferroni adjusted) were used in the statistical analysis. Significance of the obtained results was judged at the 5% level. Results The linear measurements and 3D deviation analysis revealed significant differences in some measurements but were considered clinically accepted. Digital models obtained from laser scanning of the impressions revealed the least mean differences from the gold standard ranging from (-0.24 to 0.01 mm), while CBCT scanning of the impressions mean differences ranged from (0.16 to -0.04 mm). IOS revealed the highest mean differences ranging from (0.11 to 0.33 mm). Conclusion Scanning the impression with a desktop scanner provided the highest accuracy in full arch scans followed by scanning with CBCT but with decreased surface texture of the 3D mesh. While intraoral scanners showed the least accuracy for full arch scans up till now and need further improvement in their technology. All techniques can be applied in clinical practice providing the use of high quality machines.

scholarly journals Evaluation of the reliability of measurements in cephalograms generated from cone beam computed tomography

2013 ◽  
Vol 18 (4) ◽  
pp. 53-60 ◽  
Author(s):  
Maurício Barbosa Guerra da Silva ◽  
Bruno Cabús Gois ◽  
Eduardo Franzotti Sant'Anna
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
The Other ◽  
Cone Beam ◽  
Perspective Projection ◽  
Linear Measurements ◽  
Significant Difference ◽  
Angular Measurements ◽  
Student’S T ◽  
Student’S T Test

OBJECTIVE: The purpose was to compare angular and linear measurements generated in digital cephalometric radiographs and cephalograms synthesized from three-dimensional images. METHODS: Twenty-six individuals (12 men and 14 women) with mean age of 26.3 years were selected. Digital cephalometric radiographs and CBCTs were taken on the same day. The images were imported and analyzed on Dolphin Imaging V.10.5 software, which synthesized cephalograms in perspective projection and magnification of 9.7%. A single observer marked the points and repeated the procedure with an interval of time of ten days to evaluate intraexaminer error. In the statistical analysis paired Student's t test was used to establish the correlation between the measurements. RESULTS: The angular measurements GoGn.SN and IMPA, which involved the Gonial point (Go) and the linear measurements that involved the lips presented significant difference (p < 0.05). The other measurements presented good correlation. CONCLUSION: The measurements in the synthesized cephalograms proved to be reliable.

Three dimensional cone-beam CT sialography in non tumour salivary pathologies: procedure and results

2019 ◽  
Vol 48 ◽  
pp. 226
Author(s):  
H. Bertin ◽  
R. Bonnet ◽  
M. Anquetil ◽  
A.S. Delemazure ◽  
E. Mourrain-Langlois ◽  
...  
Keyword(s):  
Cone Beam Ct ◽  
Three Dimensional ◽  
Cone Beam ◽  
Dimensional Cone

scholarly journals An In Vivo 3D Micro-CT Evaluation of Tooth Movement After the Application of Different Force Magnitudes in Rat Molar

2009 ◽  
Vol 79 (4) ◽  
pp. 703-714 ◽  
Author(s):  
Carmen Gonzales ◽  
Hitoshi Hotokezaka ◽  
Yoshinori Arai ◽  
Tadashi Ninomiya ◽  
Junya Tominaga ◽  
...  
Keyword(s):  
Tooth Movement ◽  
Three Dimensional ◽  
Element Model ◽  
Longitudinal Change ◽  
Micro Ct ◽  
Linear Measurements ◽  
Center Of Rotation ◽  
Ct Evaluation ◽  
Space Width

Abstract Objective: To investigate the precise longitudinal change in the periodontal ligament (PDL) space width and three-dimensional tooth movement with continuous-force magnitudes in living rats. Materials and Methods: Using nickel-titanium closed-coil springs for 28 days, 10-, 25-, 50-, and 100-g mesial force was applied to the maxillary left first molars. Micro-CT was taken in the same rat at 0, 1, 2, 3, 10, 14, and 28 days. The width of the PDL was measured in the pressure and tension sides from 0 to 3 days. Angular and linear measurements were used to evaluate molar position at day 0, 10, 14, and 28. The finite element model (FEM) was constructed to evaluate the initial stress distribution, molar displacement, and center of rotation of the molar. Results: The initial evaluation of PDL width showed no statistical differences among different force magnitudes. Tooth movement was registered 1 hour after force application and gradually increased with time. From day 10, greater tooth movement was observed when 10 g of force was applied. The FEM showed that the center of rotation in the molar is located in the center of five roots at the apical third of the molar roots. Conclusion: The rat's molar movement mainly consists of mesial tipping, extrusion of distal roots, intrusion of mesial root, palatal inclination, and mesial rotation. Although the initial tooth movement after the application of different force magnitudes until day 3 was not remarkably different, 10 g of force produced more tooth movement compared with heavier forces at day 28.

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