Investigating the effect of bruxism on maxillary arch length and width in children using three-dimensional digital model analysis

Abstract Background Bruxism is defined as repetitive jaw-muscle activity characterized by the grinding and clenching of teeth. The prevalence of bruxism in children is extensive, and it can cause irregularities in dental arches. The study aimed to investigate the presence of any effects of bruxism on maxillary arch length and width in children using three-dimensional (3D) digital model analysis. Method This study evaluated 30 children with bruxism. For every child with bruxism, a case control without bruxism was selected and matched for gender, age, and dentition. Digital models of the patients’ maxilla were obtained with a 3D intraoral scanner, and width and length measurements between the reference points on the maxilla were obtained on the digital models. Results The mean age of the study group was 9.13 ± 1.27. Insıgnificance differences were found between females and males within and between groups in terms of maxillary width and length. Insignificant difference was found between the control and study groups when the lengths of 3R-3L, 4R-4L, 5R-5L, 6R-6L, and IP-M were compared (p > 0.05). Conclusion Based on the study results, there were no differences in the maxillary arch length and width in patients with bruxism and patients without bruxism.

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Morphometric analysis of the palatal shape and arch dimension in subjects with palatally displaced canine

European Journal of Orthodontics ◽

10.1093/ejo/cjy080 ◽

2019 ◽

Vol 41 (5) ◽

pp. 460-467 ◽

Cited By ~ 1

Author(s):

Manuela Mucedero ◽

Matteo Rozzi ◽

Alessia Milazzo ◽

Paola Cozza

Keyword(s):

Morphometric Analysis ◽

Shape Change ◽

Three Dimensional ◽

Study Groups ◽

3D Models ◽

Permanent Teeth ◽

Control Group ◽

Linear Measurements ◽

Geometric Morphometric ◽

Maxillary Arch

Summary Objectives The aim of this study is to analyse the morphological variations of the palate shape and maxillary arch dimension in a group of subjects with unilaterally or bilaterally impacted maxillary canines compared with a control group, using three-dimensional (3D) geometric morphometric. Materials The subject of this study consisted of pre-treatment records of 46 (18 males and 28 females) patients with one or both canines palatally displaced. A control group of 26 subjects was selected from a list of orthodontic patients at the same dental hospital. The subjects were divided in two study groups: unilateral palatally displaced canine (UPDC) and bilateral palatally displaced canine (BPDC). Study casts were scanned to analyse the palate’s shape and maxillary arch dimension. The 3D geometric morphometric analysis was used to study the entirety of the shape of the palate. The virtual 3D models were measured with a specific software to analyse the maxillary arch dimension. (VAM, Vectra; Canfield Scientific, Fairfield, New Jersey, USA). Results When comparing the groups with the geometric morphometrics analysis, no significant palatal shape change was found. For the analysis of linear measurements, only a significant reduction of intercanine width was found in the UPDC and BPDC groups when compared with the control subjects. Conclusions Patients with palatally displaced permanent canine showed no maxillary transverse constriction or variation in palatal vault morphology but the absence of permanent teeth was associated with a reduction in the intercanine width.

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Evaluation of the use of digital study models in postgraduate orthodontic programs in the United States and Canada

The Angle Orthodontist ◽

10.2319/030813-197.1 ◽

2013 ◽

Vol 84 (1) ◽

pp. 62-67 ◽

Cited By ~ 15

Author(s):

Shruti Shastry ◽

Jae Hyun Park

Keyword(s):

United States ◽

New Technology ◽

Three Dimensional ◽

The United States ◽

Digital Model ◽

Digital Models ◽

Electronic Survey ◽

Storage And Retrieval ◽

The Future ◽

Plaster Model

ABSTRACT Objective: To investigate the extent, experience, and trends associated with digital model use, as well as the advantages of using a particular study model type (digital or plaster) in postgraduate orthodontic programs in the United States and Canada. Materials and Methods: An electronic survey consisting of 14 questions was sent to 72 program directors or chairpersons of accredited orthodontic postgraduate programs in the United States and Canada. Results: Fifty-one responded for a 71% response rate. Sixty-five percent of the schools use plaster study models compared with 35% that use digital models. The most common advantages of plaster models were a three-dimensional feel and the ability for them to be mounted on an articulator. The most common advantages of digital models were the ease of storage and retrieval, and the residents' exposure to new technology. About one third of the plaster model users reported that they wanted to switch to digital models in the future, with 12% planning to do so within 1 year. Conclusions: Based on our study, 35% of accredited orthodontic postgraduate programs in the United States and Canada are using digital study models in most cases treated in their programs, and the trend is for increased digital model use in the future.

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Three-dimensional palatal anatomic characteristics' correlation with dermatoglyphic heterogeneity in Angle malocclusions

The Angle Orthodontist ◽

10.2319/091718-675.1 ◽

2019 ◽

Vol 89 (4) ◽

pp. 643-650

Author(s):

Ibrahim AlShahrani ◽

Ali A. Dawasaz ◽

Sadatullah Syed ◽

Mohammed Ibrahim ◽

Rafi A. Togoo

Keyword(s):

Logistic Regression ◽

Surface Area ◽

Strong Correlation ◽

Three Dimensional ◽

3D Scanning ◽

Class Ii Malocclusion ◽

Double Loop ◽

Characteristic P ◽

The Mean ◽

Maxillary Arch

ABSTRACTObjectives:To assess correlation of dermatoglyphic (DG) pattern with quantitative palatal anatomic parameters measured using three-dimensional (3D) scanning of dental casts and to explore the possibility of utilizing these to predict future occurrence of malocclusion.Materials and Methods:Pretreatment casts of 477 Saudi Arabian patients were divided into Class I, II, and III malocclusion groups. Fingerprints were recorded for all hand digits using a digital biometric device. Maxillary arch analysis was accomplished including intercanine, intermolar distance, palatal height, and palatal area. The results were statistically analyzed.Results:The mean surface area of the palate was highest in Class II malocclusion. The DG pattern was not significantly associated with the type of malocclusion, except in the instance of the double loop characteristic (P = .05). There was a strong correlation, however, between DG characteristics like simple arch, loop, and double loop and palatal dimensions (intercanine, intermolar distance, and palatal height). Heterogeneity of DG pattern could be reliably used to predict palatal dimensions. Logistic regression revealed that only tented arch, symmetrical, spiral DG patterns and palatal area were significant but weak predictors of Angle malocclusion (P < .05).Conclusions:A novel correlation of DG pattern with 3D palatal anatomic characteristics was assessed in different Angle malocclusion classes. Few of the DG characteristics and palatal dimensions showed significant correlations. However, only some of these were significant predictors of Angle malocclusion.

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Surveying and Comparing the Arco Dei Gavi and its Historical Wooden Maquette

Geoinformatics FCE CTU ◽

10.14311/gi.6.42 ◽

2011 ◽

Vol 6 ◽

pp. 338-345

Author(s):

Francesco Guerra ◽

Paolo Vernier

Keyword(s):

Cultural Heritage ◽

Reference System ◽

Laser Scanning ◽

Three Dimensional ◽

Digital Model ◽

Dimensional Representation ◽

Digital Models ◽

3D Data ◽

Three Dimensional Representation ◽

3D Digital Model

Actually geometrics’ science offers new opportunities and interesting applications in the field of Cultural Heritage. These applications are strictly related to preservation, restoration but even to cataloging and reproducing a monument that no longer has its original integrity. The possibility of obtaining 3D data, of such a model close to reality, enables us to realize studies that sometimes are too complex or impossible. The paper will describe the study of a monumental arch, the Arco dei Gavi, built in Verona during the I sec. A.C., that was destroyed in 1805 by the Napoleonic army, and its wooden model that was realized in 1813 and it has a very important role concerning the monument’s reconstruction. The purpose is to realize two threedimensional models which can be comparable to each other, two models with recognizable differences, similarities and discontinuities about shapes and single elements that compose the monument. It should also be noted that some original parts of the monument have not been relocated but are badly preserved in a museum: the 3D digital model helps to identify these parts in their original location. The main steps of the work can be summarized in: collecting the historical documentation of Arco dei Gavi and its representations; identifying proper instruments (laser scanning and photogrammetric hardware and software); surveying the Arch and its wooden model; identifying a unique and shared reference system; comparing both digital models related to the same scale; choosing a three-dimensional representation to emphasize the results; reallocation of outstanding pieces (virtual anastylosis).

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Evaluating the Accuracy of Determining Coordinates of a Corner of a Building Measured in the RTN GNSS Mode, Having Applied the Innovative Algorithm of Vector Translation

Reports on Geodesy and Geoinformatics ◽

10.1515/rgg-2017-0002 ◽

2017 ◽

Vol 103 (1) ◽

pp. 10-21

Author(s):

Robert Krzyżek

Keyword(s):

Real Time ◽

Satellite System ◽

Reference Points ◽

Mean Error ◽

Base Points ◽

Study Results ◽

Innovative Solution ◽

The Mean ◽

Global Navigation Satellite

Abstract The study evaluates the accuracy of determining coordinates of a corner of a building measured in the RTN GNSS mode (Real Time Network Global Navigation Satellite System) using the method of line-line intersection and having applied the algorithm of vector translation, developed by the author. The performed analysis of accuracy proved a high precision in determining the points subjected to studies. An important factor in the formation of a mean error regarding the position of the corner of a building, having used the algorithm of vector translation, is the assumption of correctness of the reference points, i.e. the so-called base points, determined in the RTN GNSS mode. In this case, the base points take the role of measurement control points. The mean error of the position of the corner of a building, taking into account the innovative solution, is at the level of several centimeters. The study results presented in the article allow to positively evaluate the algorithm of vector translation in terms of accuracy of determining the position of a corner of a building, measured in real time.

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Coupled Wind-Induced Vibration Analysis of the Membrane Structure Based on Steady-State CFD

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.94-96.598 ◽

2011 ◽

Vol 94-96 ◽

pp. 598-605

Author(s):

Xu Feng Sun ◽

Shi Rong Li

Keyword(s):

Steady State ◽

Wind Velocity ◽

Membrane Structure ◽

Coupling Effect ◽

Pressure Coefficient ◽

Three Dimensional ◽

Reference Points ◽

Response Distribution ◽

The Mean ◽

Wind Induced Vibration

Because of large flexibility and strong geometric nonlinearrity, the time domain method should be applied in the analysis of wind-induced vibration for the membrane structure, and the coupling effect between the structure and the fluid should also be considered. In this problem, it is hard now to solve it directly using the technique of three-dimensional transient FSI based on CFD. So in the article, a compromise schedule is proposed, i.e, for the mean wind part, the steady-state FSI technique is applied to solve the parameter such as the mean pressure coefficient, the mean wind velocity, etc, while for the fluctuating wind part, the time integral method is used based on the stochastic function of the wind velocity formed by auto regressive method. The aerodynamic damping is considered in the solving of fluctuating part and five computing schedule are compared, result shows that it is better to use positive mean wind damping for the nodes. It is also suggested that the stochastic wind velocity functuion can be revised based on the kinetic energy distribution of the reference points. A comparison between the computing and testing results show that it is greatly improved for the fluctuating response distribution of the structure.

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Dimensional Validation of a 3D Digitization System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.809-810.878 ◽

2015 ◽

Vol 809-810 ◽

pp. 878-883

Author(s):

Francisco Santos ◽

Elena Sanchez ◽

Roberto Lopez ◽

Oscar Martin ◽

Florin Negoescu ◽

...

Keyword(s):

Three Dimensional ◽

Coordinate Measuring Machine ◽

Digital Model ◽

Digital Models ◽

A Value ◽

Three Dimensional Measurement ◽

Multiple Scan ◽

Measuring Machine ◽

Set Up ◽

System Configurations

A three-dimensional measurement system has been set up. The digital models have been obtained using a webcam and structured light. After this, a software for measuring the digital geometries has been applied. In order to validate the digital models, the workpiece has been measured in a Laboratory of Metrology by means of a Coordinate Measuring Machine. While digital models can be obtained from multiple scan system configurations, not all of them get the same degree of accuracy. After analyzing the results, it can be determined the best condition for obtaining the digital model so that discrepancies between measurements and corresponding digital model of the workpiece are minimized. Also, it has been estimated a value of measurement uncertainty for each of the models studied.

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Change Blindness in 3D Virtual Reality

10.1101/025817 ◽

2015 ◽

Cited By ~ 2

Author(s):

Madis Vasser ◽

Markus Kängsepp ◽

Jaan Aru

Keyword(s):

Virtual Reality ◽

Change Blindness ◽

Three Dimensional ◽

Search Time ◽

Head Movements ◽

Field Of View ◽

Study Results ◽

3D Environments ◽

Novel Method ◽

The Mean

In the present change blindness study subjects explored stereoscopic three dimensional (3D) environments through a virtual reality (VR) headset. A novel method that tracked the subjects' head movements was used for inducing changes in the scene whenever the changing object was out of the field of view. The effect of change location (foreground or background in 3D depth) on change blindness was investigated. Two experiments were conducted, one in the lab (n = 50) and the other online (n = 25). Up to 25% of the changes were undetected and the mean overall search time was 27 seconds in the lab study. Results indicated significantly lower change detection success and more change cycles if the changes occurred in the background, with no differences in overall search times. The results confirm findings from previous studies and extend them to 3D environments. The study also demonstrates the feasibility of online VR experiments.

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HRA Model for Hypercholesterolemia Based on a Longitudinal Health Database

Methods of Information in Medicine ◽

10.1055/s-0038-1634513 ◽

1998 ◽

Vol 37 (02) ◽

pp. 130-133

Author(s):

T. Kishimoto ◽

Y. Iida ◽

K. Yoshida ◽

M. Miyakawa ◽

H. Sugimori ◽

...

Keyword(s):

Total Cholesterol ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Model Analysis ◽

Serum Total Cholesterol ◽

Hazards Model ◽

The Mean ◽

Health Database ◽

Observation Period

AbstractTo evaluate the risk factors for hypercholesterolemia, we examined 4,371 subjects (3,207 males and 1,164 females) who received medical checkups more than twice at an AMHTS in Tokyo during the period from 1976 through 1991; and whose serum total cholesterol was under 250 mg/dl. The mean follow-up duration was 6.6 years. A self-registering questionnaire was administered at the time of the health checkup. The endpoint of this study was the onset of hypercholesterolemia when the level of serum total cholesterol was 250 mg/dl and over. We compared two prognosis groups (normal and hypercholesterol) in terms of age, examination findings and lifestyle. After assessing each variable, we employed Cox's proportional hazards model analysis to determine the factors related to the occurrence of hypercholesterolemia. According to proportional hazards model analysis, total cholesterol, triglyceride and smoking at the beginning, and hypertension during the observation period were selected in males; and total cholesterol at the beginning and age were selected in females to determine the factors related to the occurrence of hypercholesterolemia.

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Electron Holographic Nano-Characterization of Gold Catalyst at Interface

MRS Proceedings ◽

10.1557/proc-727-r2.2 ◽

2002 ◽

Vol 727 ◽

Cited By ~ 1

Author(s):

S. Ichikawa ◽

T. Akita ◽

M. Okumura ◽

M. Haruta ◽

K. Tanaka

Keyword(s):

Contact Angle ◽

Titanium Oxide ◽

Gold Catalyst ◽

Three Dimensional ◽

High Resolution Electron Microscopy ◽

Electron Holography ◽

Gold Particles ◽

Oxide Support ◽

The Mean ◽

A Charge

AbstractThe catalytic properties of nanostructured gold catalyst are known to depend on the size of the gold particles and to be activated when the size decreases to a few nanometers. We investigated the size dependence of the three-dimensional nanostructure on the mean inner potential of gold catalysts supported on titanium oxide using electron holography and high-resolution electron microscopy (HREM). The contact angle of the gold particles on the titanium oxide tended to be over 90° for gold particles with a size of over 5 nm, and below 90° for a size of below 2 nm. This decreasing change in the contact angle (morphology) acts to increase the perimeter and hence the area of the interface between the gold and titanium oxide support, which is considered to be an active site for CO oxidation. The mean inner potential of the gold particles also changed as their size decreased. The value of the inner potential of gold, which is approximately 25 V in bulk state, rose to over 40 V when the size of the gold particles was less than 2 nm. This phenomenon indicates the existence of a charge transfer at the interface between gold and titanium oxide. The 3-D structure change and the inner potential change should be attributed to the specific electronic structure at the interface, owing to both the “nano size effect” and the “hetero-interface effect.”

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