scholarly journals A reliable method for evaluating upper molar distalization: Superimposition of three-dimensional digital models

2015 ◽  
Vol 45 (2) ◽  
pp. 82 ◽  
Author(s):  
Ruhi Nalcaci ◽  
Ayse Burcu Kocoglu-Altan ◽  
Ali Altug Bicakci ◽  
Firat Ozturk ◽  
Hasan Babacan
Keyword(s):  
Reliable Method ◽  
Three Dimensional ◽  
Digital Models ◽  
Molar Distalization ◽  
Upper Molar

New design for unilateral upper molar distalization with bone anchorage system

2019 ◽  
pp. 1-4
Keyword(s):  
Patient Compliance ◽  
Tooth Movement ◽  
Molar Distalization ◽  
Anchorage System ◽  
Conventional Methods ◽  
Upper Molar ◽  
Bone Anchorage

Molar distalization is considered as a good approach for creating space. Conventional methods were depended on patient compliance but with se of mini screw, tooth movement are done more rapidly, easily and non-compliance. Our design is useful for unilateral upper molar distalization by modified power arm that is connected to mini screw by elastic chain.

scholarly journals Efficiency of the skeletonized Pendulum K appliance for non-compliance maxillary molar distalization

2021 ◽  
Author(s):  
Gero Stefan Michael Kinzinger ◽  
Jan Hourfar ◽  
Jörg Alexander Lisson
Keyword(s):  
Side Effects ◽  
Lower Percentage ◽  
Molar Distalization ◽  
Maxillary Molars ◽  
Maxillary Molar ◽  
Force Moment ◽  
Maxillary Premolars ◽  
Anchorage Loss ◽  
Upper Molar

Abstract Purpose Conventional anchorage with exclusively intraorally anchored appliances for non-compliance molar distalization combines a palatal acrylic button with periodontal anchorage. This type of anchorage is critically discussed because of the temporary hygienic impairment of the palate and the uncertain anchoring quality of the button. A purely dentally/periodontally anchored Pendulum K appliance was developed, which is exclusively anchored via four occlusal rests. The aims of this pilot study were to examine the suitability of the skeletonized Pendulum K for distalization of maxillary molars, and to investigate the quality of this alternative anchoring modality. Patients and methods In all, 10 patients received skeletonized Pendulum K appliances attached to all maxillary premolars for bilateral molar distalization. Supporting anchorage through an acrylic button adjacent to the anterior palate was not used. The pendulum springs were initially activated on both sides with a distalization force of 220 cN each and provided with uprighting and toe-in bends. The specific force/moment system was regularly reactivated intraorally by adjustment of the distal screw. Results The study demonstrates the suitability of the skeletonized Pendulum K appliance for the distalization of maxillary molars (3.28 ± 0.73 mm). Side effects on the molars were slight distal tipping (3.50 ± 2.51°/PP, 3.00 ± 1.41°/SN) and mesial inward rotation (average 2.75 ± 7.50° and 4.50 ± 12.77°). Significant anchorage loss occurred in the form of mesialization of the incisors by 1.40 ± 0.82 mm and of the first premolars by 2.28 ± 0.85 mm. Conclusion The skeletonized Pendulum K appliance allows compliance-free upper molar distalization. Exclusively dental/periodontal anchorage resulted in a lower percentage of molar distalization compared to a conventional anchoring preparation of the Pendulum K with a palatal acrylic button. Anchorage loss had a comparatively stronger effect on the anchoring premolars but less on the incisors. Typical side effects on the molars such as distal tipping and mesial inward rotation were remarkably low.

scholarly journals A New Method to Evaluate Trueness and Precision of Digital and Conventional Impression Techniques for Complete Dental Arch

2021 ◽  
Vol 11 (10) ◽  
pp. 4612
Author(s):  
KweonSoo Seo ◽  
Sunjai Kim
Keyword(s):  
Intraclass Correlation ◽  
Three Dimensional ◽  
New Method ◽  
Digital Impression ◽  
Dental Arch ◽  
Digital Models ◽  
Digital Impressions ◽  
Measuring Machine ◽  
Master Model ◽  
Conventional Impression

Purpose: The aim of this study was to present a new method to analyze the three-dimensional accuracy of complete-arch dental impressions and verify the reliability of the method. Additionally, the accuracies of conventional and intraoral digital impressions were compared using the new method. Methods: A master model was fabricated using 14 milled polyetheretherketone cylinders and a maxillary acrylic model. Each cylinder was positioned and named according to its corresponding tooth position. Twenty-five definitive stone casts were fabricated using conventional impressions of the master model. An intraoral scanner was used to scan the master model 25 times to fabricate 25 digital models. A coordinate measuring machine was used to physically probe each cylinder in the master model and definitive casts. An inspection software was used to probe cylinders of digital models. A three-dimensional part coordinate system was defined and used to compute the centroid coordinate of each cylinder. Intraclass correlation coefficient (ICC) was evaluated to examine the reliability of the new method. Independent two sample t-test was performed to compare the trueness and precision of conventional and intraoral digital impressions (α = 0.05). Results: ICC results showed that, the new method had almost perfect reliability for the measurements of the master model, conventional and digital impression. Conventional impression showed more accurate absolute trueness and precision than intraoral digital impression for most of the tooth positions (p < 0.05). Conclusions: The new method was reliable to analyze the three-dimensional deviation of complete-arch impressions. Conventional impression was still more accurate than digital intraoral impression for complete arches.

scholarly journals Comparative Analysis of Digital Models of Objects of Cultural Heritage Obtained by the “3D SLS” and “SfM” Methods

2021 ◽  
Vol 11 (12) ◽  
pp. 5321
Author(s):  
Marcin Barszcz ◽  
Jerzy Montusiewicz ◽  
Magdalena Paśnikowska-Łukaszuk ◽  
Anna Sałamacha
Keyword(s):  
Cultural Heritage ◽  
Low Cost ◽  
Three Dimensional ◽  
3D Models ◽  
Silk Road ◽  
Digital Models ◽  
Global Pandemic ◽  
University Of Technology ◽  
Three Dimensional Models ◽  
3D Digitisation

In the era of the global pandemic caused by the COVID-19 virus, 3D digitisation of selected museum artefacts is becoming more and more frequent practice, but the vast majority is performed by specialised teams. The paper presents the results of comparative studies of 3D digital models of the same museum artefacts from the Silk Road area generated by two completely different technologies: Structure from Motion (SfM)—a method belonging to the so-called low-cost technologies—and by Structured-light 3D Scanning (3D SLS). Moreover, procedural differences in data acquisition and their processing to generate three-dimensional models are presented. Models built using a point cloud were created from data collected in the Afrasiyab museum in Samarkand (Uzbekistan) during “The 1st Scientific Expedition of the Lublin University of Technology to Central Asia” in 2017. Photos for creating 3D models in SfM technology were taken during a virtual expedition carried out under the “3D Digital Silk Road” program in 2021. The obtained results show that the quality of the 3D models generated with SfM differs from the models from the technology (3D SLS), but they may be placed in the galleries of the vitrual museum. The obtained models from SfM do not have information about their size, which means that they are not fully suitable for archiving purposes of cultural heritage, unlike the models from SLS.

scholarly journals Three-Dimensional Motion Analysis of the 2nd Cervical Spinous Process at End Range Cervical Rotation in Different Scapular Positions Using 3D Digitizer

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Takahiro Otsudo ◽  
Kiyokazu Akasaka ◽  
Hiroshi Hattori ◽  
Yuki Hasebe ◽  
Akihiro Tamura ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Motion Analysis ◽  
Reliable Method ◽  
Spinous Process ◽  
Three Dimensional ◽  
Healthy Adults ◽  
Upper Cervical ◽  
Spine Disorders ◽  
Cervical Rotation

Objective. The study used a 3D digitizer to determine three-dimensional motion analysis of the 2nd cervical (C2) spinous process at end range cervical rotation with the scapula in different positions. Methods. 30 healthy adults participated in this study. Different scapula positions were adopted bilaterally and positioned passively at normal resting, depression, adduction, and abduction. Under each scapula position, bilateral end range cervical rotation and displacement of the C2 spinous process were analyzed by a 3D digitizer. Results. Displacement of the C2 spinous process relative to the occiput was significantly correlated with range of cervical rotation under all scapular positions (p<0.05). However, there were no significant differences between end range cervical rotation and displacement of the C2 spinous process relative to the occiput in any scapular position. Conclusion. These results suggest that measurement of upper cervical mobility using the 3D digitizer is a reliable method that holds promise in the evaluation of people with cervical spine disorders.

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

2014 ◽  
Vol 19 (4) ◽  
pp. 107-113 ◽  
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.

scholarly journals THREE-DIMENSIONAL GEOLOGICAL MODELING OF OIL SATURATION OF PRODUCTIVE OIL RESERVOIR BASED ON LEVERETT J-FUNCTION

2016 ◽  
pp. 7-10
Author(s):  
Ya. O. Antipin
Keyword(s):  
Porous Media ◽  
Transition Zone ◽  
Reliable Method ◽  
Three Dimensional ◽  
Hydrodynamic Modeling ◽  
Oil Reservoirs ◽  
Oil Reservoir ◽  
Geological Modeling ◽  
Oil Saturation ◽  
The Impact

The author suggests and describes the most optimal, reliable method for modeling saturation of the productive oil reservoirs The method takes into account the impact of capillary forces in porous media, water-oil transition zone. This method most fully meets the modern requirements of threedimensional geological and hydrodynamic modeling.

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