scholarly journals Risk Factors of Avulsion Fracture after Iliac Crestal Flap for Jaw Reconstruction

2021 ◽  
Vol 11 (17) ◽  
pp. 8081
Author(s):  
Ye-Joon Jo ◽  
Jun-Seok Choi ◽  
Jin-Ah Bang ◽  
Jin Kim ◽  
Seong-Yong Moon
Keyword(s):  
Risk Factors ◽  
Avulsion Fracture ◽  
Three Dimensional ◽  
Bed Rest ◽  
Reference Points ◽  
Three Dimensional Model ◽  
Fracture Group ◽  
Jaw Reconstruction ◽  
Significant Difference ◽  
Age And Sex

The iliac crestal flap is often used in maxillofacial reconstruction surgery because it has a similar bone contour to jaw bone. However, complications occur frequently in this flap, and the avulsion fracture of the anterior superior iliac spine (ASIS) occurs only in rare cases. The purpose of this study is to evaluate the risk factors affecting fractures that may occur after iliac crestal flap harvesting. In this study, we performed preoperative and postoperative CT scans of the iliac bones of 22 patients who underwent iliac crestal flaps between February 2013 and July 2019. Three of these patients had fractures within 1 month after surgery. After converting DICOM files to a three-dimensional model using Mimics software, some reference points were defined for analysis. The patients were classified into fracture and non-fracture groups. The patients’ age and sex, harvested bone, residual bone and absolute bed rest (ABR) periods were investigated. The patients’ age and sex were not associated with fracture occurrence. There was a statistically significant difference in the width of the anterior–superior part of residual bone. The fracture group showed statistically significantly shorter ABR periods. In the case of the iliac crestal flap, it was found that the factors that can affect the occurrence of fractures are the width of the residual bone and the ABR period. Iliac avulsion fracture can be prevented when the remaining bone is sufficient and the ABR period is prolonged sufficiently.

Age-Dependent Three-Dimensional Evaluation of the Spheno-Occipital Synchondrosis Using Computed Tomography

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arezoo Jahanbin ◽  
Shirin Dokht Shirazi ◽  
Elaheh Kamyabnezhad ◽  
Neda Eslami ◽  
Seyed Hosein Hoseini Zarch
Keyword(s):  
Developmental Stage ◽  
Three Dimensional ◽  
Cross Sectional ◽  
Old Patients ◽  
Significant Difference ◽  
Growth Center ◽  
Different Populations ◽  
Males And Females ◽  
Ossification Process ◽  
Age And Sex

Background: The spheno‐occipital synchondrosis (SOS) is an important growth center which plays an important role in cranial base development and can define the final relation of SOS with the upper and lower jaws. The morphology and fusion degree of SOS varies in different ages among different populations. Objectives: Thus, the aim of this study was to evaluate the age and sex dependence of ossification of the spheno-occipital synchondrosis in the Iranian population using CBCT. Methods: This cross-sectional retrospective study was performed on 517 CBCT images of 6- to 18-year-old patients in Mashhad, Iran. Patients with obvious pathology or fractures were excluded from the study. The SOS ossification was classified into four stages from 0 to 3. Two independent observers scored the images. The ossification stage of the SOS was classified according to the age and sex of the patients. Kruskal-Wallis and Kendall’s tau-b used for statistical analysis. Results: In this study, 517 samples of 260 females (50.3%) and 257 males (49.7%) with a mean age of 12.03 ± 3.74 years were examined. A significant difference did not exist between males and females regarding their stage of SOS ossification, although males were younger at the SOS transitional stages of 0 to 1, and 1 to 2 compared to females. Also, the SOS starts the ossification process at the age of 11 in females and 10.8 in males. Conclusions: The present study showed in the mean age of 16.81 ± 1.12 years, most subjects were in developmental stage 3. Due to the fact that in developmental stage 3 SOS closes, there were no passive maxillary growth after this time. In none of the SOS stages, females and males differed significantly in mean age (P > 0.05). The age of the onset of SOS closure in females was 11 years and in males it was about 10.8 years.

Abstract 14520: Differences in Left Atrial Size and Function and Supraventricular Arrhythmias Between Blacks and Whites in the Atherosclerosis Risk in Communities (ARIC) Study: Implications for AF Pathogenesis

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Wendy Wang ◽  
Riccardo M Inciardi ◽  
Faye L Norby ◽  
Michael J Zhang ◽  
Jorge L Reyes ◽  
...  
Keyword(s):  
Risk Factors ◽  
Racial Differences ◽  
Left Atrial ◽  
Atherosclerosis Risk In Communities ◽  
Significant Difference ◽  
Blacks And Whites ◽  
The Difference ◽  
And Function ◽  
Aric Study ◽  
Age And Sex

Introduction: Black Americans have more atrial fibrillation (AF) risk factors but lower AF risk than whites. Left atrial (LA) enlargement, impaired LA function, frequent premature atrial contractions (PAC), and atrial tachycardia (AT) are risk factors for AF. Racial differences in LA size and function, PAC, or AT may exist that could explain the difference in AF risk. Hypothesis: Whites have higher PAC and AT frequency than blacks. Additionally, whites have larger LA size and lower LA function than blacks, which may contribute to the racial difference in AF. Methods: We included 1,623 ARIC participants free of AF who had 2D-echocardiograms at visit 5 (2011-2013) and wore a 2-week continuous heart monitor, the Zio ® XT Patch, at visit 6 (2016-2017). Weighted linear regression was used to analyze the association of race with LA size and function, as well as runs of AT per day and PAC per hour. Results: At visit 5, participants were 74 (4) years old, 58% were female, and 26% were black. AT runs were detected in 87% of blacks and 92% of whites, respectively (p=0.002). Among participants with >0 runs of AT per day (n=1480), blacks had 48% (95% CI: 21%-66%) fewer runs of AT per day than whites after adjustment for cardiovascular (CV) risk factors † . There was no significant difference in PAC frequency between blacks and whites. After adjusting for age and sex, blacks had greater LA size and lower LA function than whites; these differences attenuated after adjusting for CV risk factors (Table). Conclusion: Blacks have greater age and sex-adjusted abnormality in LA size and function than whites, likely due to higher prevalence of CV risk factors. Yet, blacks have lower propensity for AT. More research is needed to elucidate the mechanisms underlying the resistance to atrial arrhythmogenesis in blacks despite greater adverse LA remodeling.

Use of computed tomography data for forensic identification of an individual

2020 ◽  
Vol 6 (4) ◽  
pp. 41-45
Author(s):  
Sergey V. Leonov ◽  
Julia P. Shakiryanova
Keyword(s):  
Computed Tomography ◽  
Computer Tomography ◽  
Soft Tissues ◽  
Three Dimensional ◽  
Reference Points ◽  
Forensic Identification ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
The Face ◽  
Tomography Data

Background: The article presents our own experience of using computer tomography for identification of individuals with known results. Aims: The aim of the study was to verify the possibility of performing an identification study using a three-dimensional model obtained from computed tomography of the head. Identification was performed using a three-dimensional model of the head, based on computer tomography sections made in various projections, with a step of 1.231.25 mm. Two-dimensional images of the face (photos) were used for comparison. All comparative studies were conducted using approved methods of craniofacial and portrait identification: by reference points and contours. The experiment used a computer program that allows you to export DICOM-files of computed tomography results to other formats (InVesalius), as well as computer programs that directly work with the research objects (Autodesk 3ds Max, alternative programs Adobe Photoshop, Smith Micro Poser Pro). Results: In the course of research, it was found that, having computer tomography data of the head, it is possible to conduct identification studies on the following parameters: on the reconstructed three-dimensional model of the soft tissues of the face, on the three-dimensional model of the skull (craniofacial identification), on the features of the structure of the ear. Conclusion: Positive results were obtained when comparing objects, which makes it advisable to use them in practical and scientific activities.

Impact of Welding Sequence on the CRDM Nozzle-to-Vessel Weld Stress Analysis

2004 ◽  
Author(s):  
Yaoshan Chen ◽  
David Rudland ◽  
Gery Wilkowski
Keyword(s):  
Computing Time ◽  
Three Dimensional ◽  
Welding Process ◽  
Element Model ◽  
Three Dimensional Model ◽  
Control Rod ◽  
Moving Source ◽  
Welding Sequence ◽  
Significant Difference ◽  
Three Dimensional Finite Element

A three-dimensional finite element model is presented to simulate the welding process of the side-hill control-rod-drive-mechanism (CRDM) nozzle to the vessel head. Emphasis is given to how the weld is laid out in the analysis so that accurate residual stress results can be obtained while the required computing time is viable. In the order of complexity, three approaches are examined in this study: a) the simultaneous approach, i.e., the weld bead (therefore the heat associated with it) is put in the model in a uniform fashion; b) the piece-by-piece approach, i.e., the weld is laid out segment by segment; c) the moving-source approach where the analysis is done by simulating the moving heat source. It is found that there is a significant difference between the stress results by the uniform approach and the piece-by-piece approach. While the moving source method gives the closet representation of the welding process, the computing time for such a multi-pass, three-dimensional model is still prohibitive. The natural choice is therefore the piece-by-piece approach, with the number of segments for the weld dependent on the weld parameters and the geometries of the nozzle and vessel head.

scholarly journals Influence of Voxel Size on CBCT Images for Dental Implants Planning

2021 ◽  
Author(s):  
Ricardo Kehrwald ◽  
Hebert Sampaio de Castro ◽  
Samira Salmeron ◽  
Ricardo Alves Matheus ◽  
Gustavo Machado Santaella ◽  
...  
Keyword(s):  
Gold Standard ◽  
Three Dimensional ◽  
Reference Points ◽  
Bone Thickness ◽  
Voxel Size ◽  
Significance Level ◽  
Significant Difference ◽  
Bone Height ◽  
Digital Caliper

Abstract Objective This study was developed to evaluate the influence of voxel size on bone measurements for implant planning. Materials and Methods The research was performed by using edentulous synthetic human mandibles with different levels of bone resorption. For each mandible, height and bone thickness were measured with a digital caliper. The PaX-i3d device was used to acquire the volumes of the five mandibles, with 50kVp, 4 mA, and a voxel size of 0.08 mm. After the acquisition, the images were reconstructed in the software CS three-dimensional Imaging, with four different sizes of voxels: 0.1, 0.2, 0.3, and 0.4 mm. All volumes were analyzed by a single evaluator who performed measurements to obtain bone height and thickness, using the reference points that were considered in obtaining the gold standard. The data were analyzed by ANOVA with a significance level of 5%. Results There was no significant difference in the measurements obtained with different voxel sizes, both for bone height measurements and bone thickness. There was no statistically significant difference in measurements in thickness in comparison to the gold standard. Conclusion When necessary, to measure height and bone thickness, it is possible to recommend voxel images of larger size (0.40 mm) without compromising the quality of the patient's clinical planning.

scholarly journals Distal Insertional Footprint of the Brachialis Muscle: 3D Morphometric Study

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Srinath Kamineni ◽  
Abdo Bachoura ◽  
William Behrens ◽  
Ellora Kamineni ◽  
Andrew Deane
Keyword(s):  
Three Dimensional ◽  
Muscle Length ◽  
Morphometric Study ◽  
Three Dimensional Model ◽  
Age Related ◽  
Muscle Insertion ◽  
Projected Length ◽  
Brachialis Muscle ◽  
Significant Difference ◽  
Surface Length

Objective. The purpose of this study is to describe the three-dimensional morphometry of the brachialis muscle at its distal attachment to the ulna. Methods. Fifty cadaveric elbows were dissected and the brachialis distal insertion was isolated on the ulna bone and probed with a three-dimensional digitizer, to create a three-dimensional model of the footprint. Measurements and analysis of each footprint shape were recorded and compared based on gender and size. Results. There was significant gender difference in the surface length (P= 0.002) and projected length (P= 0.001) of the brachialis footprint. The shapes of the footprint also differed among the specimens. Conclusion. The shape of the brachialis muscle insertion differed among all the specimens without significant variation in gender or sides. There was also a significant difference in muscle length between males and females with little difference in the width and surface area. Significance. The information obtained from this study is important for kinematic understanding and surgical procedures around the elbow joint as well as the understanding of the natural age related anatomy of the brachialis footprint morphology.

scholarly journals Student Learning about Biomolecular Self-Assembly Using Two Different External Representations

2013 ◽  
Vol 12 (3) ◽  
pp. 471-482 ◽  
Author(s):  
Gunnar E. Höst ◽  
Caroline Larsson ◽  
Arthur Olson ◽  
Lena A. E. Tibell
Keyword(s):  
Student Learning ◽  
Self Assembly ◽  
Dynamic Properties ◽  
Three Dimensional ◽  
External Representations ◽  
Three Dimensional Model ◽  
Written Responses ◽  
Significant Difference ◽  
Model Condition ◽  
The Impact

Self-assembly is the fundamental but counterintuitive principle that explains how ordered biomolecular complexes form spontaneously in the cell. This study investigated the impact of using two external representations of virus self-assembly, an interactive tangible three-dimensional model and a static two-dimensional image, on student learning about the process of self-assembly in a group exercise. A conceptual analysis of self-assembly into a set of facets was performed to support study design and analysis. Written responses were collected in a pretest/posttest experimental design with 32 Swedish university students. A quantitative analysis of close-ended items indicated that the students improved their scores between pretest and posttest, with no significant difference between the conditions (tangible model/image). A qualitative analysis of an open-ended item indicated students were unfamiliar with self-assembly prior to the study. Students in the tangible model condition used the facets of self-assembly in their open-ended posttest responses more frequently than students in the image condition. In particular, it appears that the dynamic properties of the tangible model may support student understanding of self-assembly in terms of the random and reversible nature of molecular interactions. A tentative difference was observed in response complexity, with more multifaceted responses in the tangible model condition.

Reflections on Photogrammetry

2018 ◽  
pp. 34-41
Author(s):  
Alexander W. Schindler
Keyword(s):  
Object Recognition ◽  
Machine Vision ◽  
Three Dimensional ◽  
Standard Technique ◽  
Ground Truth ◽  
Reference Points ◽  
Two Dimensional ◽  
Three Dimensional Model ◽  
Technological Field ◽  
Image Capturing

This article presents an overview of the history, principles, and current developments in the media technological field of photogrammetry. By chronicling the isomorphic shift taking place in image capturing, we seek to show that photogrammetry has led the way forward in seeing technical images not only as two dimensional projections, but as three-dimensional model-based images. In the mid-nineteenth century, photogrammetry was first used for the documentation of architectural objects and it later became a standard technique in aerial photography. Although its fields of application have become more extensive, photogrammetry’s basic principle hasn’t fundamentally changed: it is still defined as the three- dimensional geometric reconstruction of two-dimensional photographs through the measuring of reference points. With digital technological standards and advances in camera technology, photogrammetric imaging nowadays is intensively used for object recognition in machine vision and robotics. Beside this, photogrammetry is also opening new possibilities for documentation in the fields of investigative arts, this being explored with a discussion on the “Ground Truth” project from Forensic Architecture. Keywords: investigative art, machine vision, object recognition, photogrammetry, photography

scholarly journals Determination of Age and Sex Using Bimastoid Diameter: a Cone Beam Computed Tomography Study

2021 ◽  
pp. 388-394
Author(s):  
Özlem Okumuş
Keyword(s):  
Computed Tomography ◽  
Sex Determination ◽  
Cone Beam Computed Tomography ◽  
Three Dimensional ◽  
Population Data ◽  
High Rate ◽  
Cone Beam ◽  
Mastoid Process ◽  
Significant Difference ◽  
Age And Sex

This study aimed to investigate the possibility of age and sex determination using bimastoid diameter with cone-beam computed tomography (CBCT). This retrospective study investigated 100 female and 100 male patients aged 18-83 years (mean age: 45.55±16.28 years). To measure bimastoid diameter, the appropriate image was chosen from sagittal, coronal, and axial images of CBCT in which the measurement points could be best detected. The distance between the points of the mastoid process was measured using three-dimensional coronal reconstruction. The mean bimastoid breadth was 106.12±6.22mm. The bimastoid diameter in male cases was higher than that in female cases (110.69±4.53mm vs. 101.65±4.00mm). There was no significant difference in bimastoid breadth with advancing age. For sex determination, morphometric measurements of bimastoid diameter ensured a high rate of dimorphism in the Turkish subpopulation. CBCT morphometric analysis may be reliable and convenient for evaluating sex and may be recommended to compare population data.

scholarly journals Digital analysis of tooth sizes among individuals with different malocclusions: A study using three-dimensional digital dental models

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110381
Author(s):  
Beyza Karadede Ünal ◽  
Deniz Dellaloğlu
Keyword(s):  
Three Dimensional ◽  
Class Ii ◽  
Tooth Size ◽  
Digital Models ◽  
Three Dimensional Model ◽  
Digital Format ◽  
Significant Difference ◽  
Three Dimensional Measurement ◽  
Anterior Ratio ◽  
Overall Ratio

Objective: It is aimed to examine the tooth sizes of digital models of patients with different malocclusions with the help of three-dimensional measurement software. Methods: Digital models of 252 patients aged between 13 and 25 years of age were included. According to the Angle classification, three different malocclusion groups were allocated such that there were 84 patients in each group, plaster models of patients scanned with the three-dimensional model browser 3Shape R700 3D Scanner (3Shape A/S Copenhagen, Denmark) and transferred to the digital format. 3Shape Ortho Analyzer (3Shape A/S Copenhagen, Denmark) software was used for making the necessary tooth size measurements. Results: When the measurements were evaluated, it was determined that significant changes occurred between tooth sizes of individuals with different malocclusions. Generally, higher values were observed in mesiodistal and buccolingual tooth dimensions of class II individuals compared to other groups. There was no difference between the groups in the anterior ratio values, but when the overall ratio values were evaluated among the groups, a statistically significant difference was determined. Class II malocclusion group was found to have a significantly lower overall ratio of occurrence. Conclusion: Individuals with different malocclusions differ in tooth size.

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