Accurate measurement of mitral annular area by using single and biplane linear measurements: comparison of conventional methods with the three-dimensional planimetric method

AbstractTo test the effects of domestication on craniofacial skeletal morphology, we used three-dimensional geometric morphometrics (GM) along with linear and endocranial measurements to compare selected (domesticated) and unselected foxes from the Russian Farm-Fox Experiment to wild foxes from the progenitor population from which the farmed foxes are derived. Contrary to previous findings, we find that domesticated and unselected foxes show minimal differences in craniofacial shape and size compared to the more substantial differences between the wild foxes and both populations of farmed foxes. GM analyses and linear measurements demonstrate that wild foxes differ from farmed foxes largely in terms of less cranial base flexion, relatively expanded cranial vaults, and increased endocranial volumes. These results challenge the assumption that the unselected population of foxes kept as part of the Russian Farm-Fox experiment are an appropriate proxy for ‘wild’ foxes in terms of craniofacial morphology and highlight the need to include wild populations in further studies of domestication syndrome to disentangle the phenotypic effects of multiple selection pressures. These findings also suggest that marked increases in docility cannot be reliably diagnosed from shape differences in craniofacial skeletal morphology.

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

The Angle Orthodontist ◽

10.2319/071308-366.1 ◽

2009 ◽

Vol 79 (4) ◽

pp. 703-714 ◽

Cited By ~ 29

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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Tooth-size discrepancy: A comparison between manual and digital methods

Dental Press Journal of Orthodontics ◽

10.1590/2176-9451.19.4.107-113.oar ◽

2014 ◽

Vol 19 (4) ◽

pp. 107-113 ◽

Cited By ~ 11

Author(s):

Gabriele Dória Cabral Correia ◽

Fernando Antonio Lima Habib ◽

Carlos Jorge Vogel

Keyword(s):

Three Dimensional ◽

Diagnostic Tools ◽

Tooth Size ◽

Digital Models ◽

Linear Measurements ◽

Length Discrepancy ◽

Technological Advances ◽

Size Discrepancy ◽

Digital Methods ◽

Plaster Models

INTRODUCTION: Technological advances in Dentistry have emerged primarily in the area of diagnostic tools. One example is the 3D scanner, which can transform plaster models into three-dimensional digital models. OBJECTIVE: This study aimed to assess the reliability of tooth size-arch length discrepancy analysis measurements performed on three-dimensional digital models, and compare these measurements with those obtained from plaster models. MATERIAL AND METHODS: To this end, plaster models of lower dental arches and their corresponding three-dimensional digital models acquired with a 3Shape R700T scanner were used. All of them had lower permanent dentition. Four different tooth size-arch length discrepancy calculations were performed on each model, two of which by manual methods using calipers and brass wire, and two by digital methods using linear measurements and parabolas. RESULTS: Data were statistically assessed using Friedman test and no statistically significant differences were found between the two methods (P > 0.05), except for values found by the linear digital method which revealed a slight, non-significant statistical difference. CONCLUSIONS: Based on the results, it is reasonable to assert that any of these resources used by orthodontists to clinically assess tooth size-arch length discrepancy can be considered reliable.

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Accuracy of digital dental models and three-dimensional printed dental models in linear measurements and Bolton analysis

F1000Research ◽

10.12688/f1000research.31865.1 ◽

2021 ◽

Vol 10 ◽

pp. 180

Author(s):

William Suryajaya ◽

Maria Purbiati ◽

Nada Ismah

Keyword(s):

Treatment Planning ◽

Interobserver Reliability ◽

Intraclass Correlation ◽

Three Dimensional ◽

3D Printer ◽

Intraoral Scanner ◽

Linear Measurements ◽

Dental Model ◽

Dental Models ◽

Digital Dental Models

Background: Due to advances in digital technology, it is possible to obtain digital dental models through intraoral scanning. The stereolithographic data collected from the scanner can subsequently be printed into a three-dimensional dental model in resinic material. However, the accuracy between digital dental models and printed dental models needs to be evaluated since it might affect diagnosis and treatment planning in orthodontic treatment. This study aimed to evaluate the accuracy of digital models scanned by a Trios intraoral scanner and three-dimensional dental models printed using a Formlabs 2 3D printer in linear measurements and Bolton analysis. Methods: A total of 35 subjects were included in this study. All subjects were scanned using a Trios intraoral scanner to obtain digital study models. Stereolithographic data from previous scanning was printed using a Formlabs 2 3D printer to obtain printed study models. Mesiodistal, intercanine, intermolar, and Bolton analysis from all types of study models were measured. The intraclass correlation coefficient was used to assess intraobserver and interobserver reliability. All data were then statistically analyzed. Results: The reliability tests were high for both intraobserver and interobserver reliability, which demonstrates high reproducibility for all measurements on all model types. Most of the data compared between study models showed no statistically significant differences, though some data differed significantly. However, the differences are considered clinically insignificant. Conclusion: Digital dental models and three-dimensional printed dental models may be used interchangeably with plaster dental models for diagnostic and treatment planning purposes. Keywords: Accuracy, 3D printing, digital dental model, printed dental model.

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The validation study on a three-dimensional burn estimation smart-phone application: accurate, free and fast?

Burns & Trauma ◽

10.1186/s41038-018-0109-0 ◽

2018 ◽

Vol 6 ◽

Cited By ~ 4

Author(s):

A. K. W. Cheah ◽

T. Kangkorn ◽

E. H. Tan ◽

M. L. Loo ◽

S. J. Chong

Keyword(s):

Surface Area ◽

Body Surface Area ◽

Body Surface ◽

Validation Study ◽

Total Body Surface Area ◽

Three Dimensional ◽

Smart Phone ◽

Conventional Methods ◽

Total Body ◽

Smart Phone Application

Abstract Background Accurate total body surface area burned (TBSAB) estimation is a crucial aspect of early burn management. It helps guide resuscitation and is essential in the calculation of fluid requirements. Conventional methods of estimation can often lead to large discrepancies in burn percentage estimation. We aim to compare a new method of TBSAB estimation using a three-dimensional smart-phone application named 3D Burn Resuscitation (3D Burn) against conventional methods of estimation—Rule of Palm, Rule of Nines and the Lund and Browder chart. Methods Three volunteer subjects were moulaged with simulated burn injuries of 25%, 30% and 35% total body surface area (TBSA), respectively. Various healthcare workers were invited to use both the 3D Burn application as well as the conventional methods stated above to estimate the volunteer subjects’ burn percentages. Results Collective relative estimations across the groups showed that when used, the Rule of Palm, Rule of Nines and the Lund and Browder chart all over-estimated burns area by an average of 10.6%, 19.7%, and 8.3% TBSA, respectively, while the 3D Burn application under-estimated burns by an average of 1.9%. There was a statistically significant difference between the 3D Burn application estimations versus all three other modalities (p < 0.05). Time of using the application was found to be significantly longer than traditional methods of estimation. Conclusions The 3D Burn application, although slower, allowed more accurate TBSAB measurements when compared to conventional methods. The validation study has shown that the 3D Burn application is useful in improving the accuracy of TBSAB measurement. Further studies are warranted, and there are plans to repeat the above study in a different centre overseas as part of a multi-centre study, with a view of progressing to a prospective study that compares the accuracy of the 3D Burn application against conventional methods on actual burn patients.

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Calibration of Test Diameter and Area As Proxies For Body Size in the Planktonic Foraminifer Globoconella Puncticulata

The Journal of Foraminiferal Research ◽

10.2113/gsjfr.48.3.241 ◽

2018 ◽

Vol 48 (3) ◽

pp. 241-245 ◽

Cited By ~ 1

Author(s):

Anieke Brombacher ◽

Leanne E. Elder ◽

Pincelli M. Hull ◽

Paul A. Wilson ◽

Thomas H. G. Ezard

Keyword(s):

Body Size ◽

Morphological Change ◽

Statistical Power ◽

Three Dimensional ◽

Body Volume ◽

Test Diameter ◽

Linear Measurements ◽

Cross Sectional ◽

Test Volume ◽

Computed Tomography Scanning

Abstract Body size is one of the most commonly measured traits in ecology and evolution because it covaries with environmental (e.g., temperature, latitude, degree of population isolation) and life-history (e.g., metabolic rate, generation time) traits. However, the driving mechanisms of body size variation in the distant geological past are poorly known and complicated by partial specimen recovery, limited population-level sampling, and the use of linear measurements as proxies for three-dimensional volumetric-size data. How much information are we missing by using approximate metrics of body size? Here we examine this question in an evolving lineage of planktonic foraminifera. We measure test diameter and surface area of over 500 individuals of the species Globoconella puncticulata using two-dimensional images. These results are compared with measurements of test volume of the same individuals as measured by a recently developed high-throughput method for analysing three-dimensional morphometrics as well as high-resolution three-dimensional computed tomography scanning. Our results show that even in a lineage showing substantial morphological change, a cross-sectional test area can provide a consistent proxy for body volume. Approximating body volume with one-dimensional (linear) size measurements is more problematic as it systematically over- and underestimates the smallest and largest tests, respectively. In our study, shape (here measured as shell-aspect ratio) only explained marginally more variation when included in the regressions. The use of 3D light microscopy introduces a small degree of scatter in the data, but the number of individuals necessary to detect trends in body size with sufficient statistical power is comparable to the sample size required for other traits. These results imply that even in an evolving lineage undergoing substantial morphological change, cross-sectional area can provide a consistent proxy for body size.

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Charuco Board-Based Omnidirectional Camera Calibration Method

Electronics ◽

10.3390/electronics7120421 ◽

2018 ◽

Vol 7 (12) ◽

pp. 421 ◽

Cited By ~ 11

Author(s):

Gwon An ◽

Siyeong Lee ◽

Min-Woo Seo ◽

Kugjin Yun ◽

Won-Sik Cheong ◽

...

Keyword(s):

Camera Calibration ◽

Mean Absolute Error ◽

Three Dimensional ◽

Absolute Error ◽

Calibration Method ◽

Feature Points ◽

Omnidirectional Camera ◽

Reprojection Error ◽

Conventional Methods ◽

Better Than

In this paper, we propose a Charuco board-based omnidirectional camera calibration method to solve the problem of conventional methods requiring overly complicated calibration procedures. Specifically, the proposed method can easily and precisely provide two-dimensional and three-dimensional coordinates of patterned feature points by arranging the omnidirectional camera in the Charuco board-based cube structure. Then, using the coordinate information of the feature points, an intrinsic calibration of each camera constituting the omnidirectional camera can be performed by estimating the perspective projection matrix. Furthermore, without an additional calibration structure, an extrinsic calibration of each camera can be performed, even though only part of the calibration structure is included in the captured image. Compared to conventional methods, the proposed method exhibits increased reliability, because it does not require additional adjustments to the mirror angle or the positions of several pattern boards. Moreover, the proposed method calibrates independently, regardless of the number of cameras comprising the omnidirectional camera or the camera rig structure. In the experimental results, for the intrinsic parameters, the proposed method yielded an average reprojection error of 0.37 pixels, which was better than that of conventional methods. For the extrinsic parameters, the proposed method had a mean absolute error of 0.90° for rotation displacement and a mean absolute error of 1.32 mm for translation displacement.

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Cone Beam Computed Tomography 3D Reconstruction of the Mandibular Condyle

The Angle Orthodontist ◽

10.2319/072007-339.1 ◽

2008 ◽

Vol 78 (5) ◽

pp. 880-888 ◽

Cited By ~ 37

Author(s):

Brian Schlueter ◽

Ki Beom Kim ◽

Donald Oliver ◽

Gus Sortiropoulos

Keyword(s):

Computed Tomography ◽

Soft Tissue ◽

3D Reconstruction ◽

Cone Beam Computed Tomography ◽

Three Dimensional ◽

Mandibular Condyle ◽

Cone Beam ◽

Low Density ◽

Mineral Density ◽

Linear Measurements

Abstract Objective: To determine the ideal window level and width needed for cone beam computed three-dimensional (3D) reconstruction of the condyle. Materials and Methods: Linear dimensions were measured with a digital caliper to assess the anatomic truth for 50 dry human mandibular condyles. Condyles were scanned with the i-CAT cone beam computed tomography (CBCT) and 3D-models were reconstructed. Three linear three-dimensional measurements were made on each of the 50 condyles at 8 different Hounsfield unit (HU) windows. These measurements were compared with the anatomic truth. Volumetric measurements were also completed on all 50 condyles, at 23 different window levels, to define the volumetric distribution of bone mineral density (BMD) within the condyle. Results: Significant differences were found in two of the three linear measurement groups at and below the recommended viewing window for osseous structures. The most accurate measurements were made within the soft tissue range for HU window levels. Volumetric distribution measurements revealed that the condyles were mostly comprised of low-density bone, and that condyles exhibiting significant changes in linear measurements were shown to have higher percentages of low-density bone than those condyles with little change from the anatomic truth. Conclusions: CBCT assessment of the mandibular condyle, using the 3D reconstruction, is most accurate when accomplished at density levels below that recommended for osseous examination. However, utilizing lower window levels which extend into the soft tissue range, may compromise one's capacity to view the bony topography.

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Cephalometric measurements from 3D reconstructed images compared with conventional 2D images

The Angle Orthodontist ◽

10.2319/121210-717.1 ◽

2011 ◽

Vol 81 (5) ◽

pp. 856-864 ◽

Cited By ~ 29

Author(s):

Natalia Zamora ◽

Jose M. Llamas ◽

Rosa Cibrián ◽

Jose L. Gandia ◽

Vanessa Paredes

Keyword(s):

Three Dimensional ◽

Cone Beam ◽

Two Dimensional ◽

Linear Measurements ◽

3D Reconstructions ◽

Software Packages ◽

Mandibular Plane ◽

Different Types ◽

Cephalometric Measurements ◽

2D Images

Abstract Objective: To assess whether the values of different measurements taken on three-dimensional (3D) reconstructions from cone-beam computed tomography (CBCT) are comparable with those taken on two-dimensional (2D) images from conventional lateral cephalometric radiographs (LCRs) and to examine if there are differences between the different types of CBCT software when taking those measurements. Material and Methods: Eight patients were selected who had both an LRC and a CBCT. The 3D reconstructions of each patient in the CBCT were evaluated using two different software packages, NemoCeph 3D and InVivo5. An observer took 10 angular and 3 linear measurements on each of the three types of record on two different occasions. Results: Intraobserver reliability was high except for the mandibular plane and facial cone (from the LCR), the Na-Ans distance (using NemoCeph 3D), and facial cone and the Ans-Me distance (using InVivo5). No statistically significant differences were found for the angular and linear measurements between the LCRs and the CBCTs for any measurement, and the correlation levels were high for all measurements. Conclusion: No statistically significant differences were found between the angular and linear measurements taken with the LCR and those taken with the CBCT. Neither were there any statistically significant differences between the angular or linear measurements using the two CBCT software packages.

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Taurodontism and Van der Woude Syndrome

The Angle Orthodontist ◽

10.2319/081707-384.1 ◽

2008 ◽

Vol 78 (5) ◽

pp. 832-837 ◽

Cited By ~ 16

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.

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