scholarly journals Optimal Position of Attachment for Removable Thermoplastic Aligner on the Lower Canine Using Finite Element Analysis

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3369 ◽  
Author(s):  
Won-Hyeon Kim ◽  
Kyoungjae Hong ◽  
Dohyung Lim ◽  
Jong-Ho Lee ◽  
Yu Jung ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Shape ◽  
Torque Control ◽  
Element Analysis ◽  
Optimal Position ◽  
Tooth Shape ◽  
Lingual Side ◽  
Lower Canine ◽  
Recent Developments

Malocclusion is considered as a developmental disorder rather than a disease, and it may be affected by the composition and proportions of masseter muscle fibers. Orthodontics is a specialty of dentistry that deals with diagnosis and care of various irregular bite and/or malocclusion. Recent developments of 3D scanner and 3D printing technology has led to the use of a removable thermoplastic aligner (RTA), which is widely used due to its aesthetic excellence, comfortableness, and time efficiency. However, orthodontics using only an RTA has lower treatment efficacy and accuracy due to the differing movement of teeth from the plan. In order to improve these disadvantages, attachments were used, and biomechanical analyses were performed with and without them. However, there is insufficient research on the movement of teeth and the transfer of load according to the attachment position and shape. Therefore, in our study, we aimed to identify the optimal shape and position of attachments by analyzing various shapes and positions of attachments. Through 3D finite element analysis (FEA), simple tooth shape and mandibular canine shape were extracted in order to construct the orthodontics model which took into account the various shapes and positions of attachments. The optimal shape of a cylinder was derived through the FEA of simple tooth shape and analyzing various positions of attachments on teeth revealed that fixing the attachments at the lingual side of the tooth rather than the buccal side allowed for torque control and an effective movement of the teeth. Therefore, we suggest fixing the attachments at the lingual side rather than the buccal side of the tooth to induce effective movement of teeth in orthodontic treatment with the RTA in case of canine teeth.

Some Recent Developments in Pressure Vessel Design by Analysis

1994 ◽  
Vol 208 (1) ◽  
pp. 23-29 ◽  
Author(s):  
D Mackenzie ◽  
J T Boyle ◽  
J Spence
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Limit Analysis ◽  
Pressure Vessel ◽  
Significant Problem ◽  
Code Design ◽  
Element Analysis ◽  
Stress Classification ◽  
Recent Developments ◽  
Design Requirements

Stress classification is a significant problem in pressure vessel design by analysis, especially if the design is based on solid finite element analysis. Stress categorization may be circumvented if the design is based on elastic-plastic or limit analysis but the degree of difficulty commonly associated with these types of analysis makes this approach unattractive to many designers. In this paper, a brief survey of a number of recent developments in pressure vessel design by analysis is discussed and assessed in light of Code design requirements.

scholarly journals An Interdisciplinary Approach to the Nanomanipulation of SiO2 Nanoparticles: Design, Fabrication and Feasibility

2018 ◽  
Vol 8 (12) ◽  
pp. 2645 ◽  
Author(s):  
Igor Luisetto ◽  
Simonetta Tuti ◽  
Eleonora Marconi ◽  
Andrea Veroli ◽  
Alessio Buzzin ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Scientific Community ◽  
Dendritic Structure ◽  
Interdisciplinary Approach ◽  
Sio2 Nanoparticles ◽  
Element Analysis ◽  
Recent Developments ◽  
Mesoporous Nanoparticles ◽  
Set Up

Although some recent developments in nanotechnology made the prospects of a direct mechanical manipulation of micro- or nano-objects quite realistic, there are still several concerns and difficulties that affect such an endeavor. This is probably due to the large base of knowledge that is necessary to approach the problem of handling a nano-object by means of a nano- or micro-device. Therefore, any progress in this field is possible only by means of an integrated and interdisciplinary approach, which takes into account different aspects of the phenomenon. During the actual pioneering phase, there is a certain convenience in handling nano-objects that: (a) have peculiar known characteristics; (b) are easily recognizable, and (c) are interesting to the scientific community. This paper presents the interdisciplinary activities that were necessary to set up an experiment where specifically synthesized SiO2 particles came in contact with the tips of specifically-designed and -fabricated nanomanipulators. SiO2 mesoporous nanoparticles (KCC-1), having a peculiar dendritic structure, have been selected as a suitable nano-object because of the possibility to easily modulate their morphology. The expected contact force has been also calculated by means of Finite Element Analysis (FEA) electro-mechanical simulations.

scholarly journals Tooth Shape Adaptations in Aglyphous Colubrid Snakes Inferred from 3D Geometric Morphometrics and Finite Element Analysis

2019 ◽  
Author(s):  
Mahdi Rajabizadeh ◽  
Sam Van Wassenbergh ◽  
Christophe Mallet ◽  
Martin Rücklin ◽  
Anthony Herrel
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Geometric Morphometrics ◽  
Yield Criterion ◽  
Sister Group ◽  
Element Analysis ◽  
Tooth Shape ◽  
3D Geometric Morphometrics ◽  
Von Mises Yield Criterion ◽  
Von Mises

AbstractTo date there are few detailed and quantitative studies investigating the evolution of the tooth shape and function in Aglyphous snakes in relation to diet. To study dental adaptations to diet, a lineage that is of particular interest due to its large range of adult body sizes, is the one including dwarfed snakes of the genus Eirenis and their immediate sister group, whip snakes of the genus Dolichophis. A considerable evolutionary decrease in the size is observed from a Dolichophis-like ancestor to the miniature Eirenis, coupled with a considerable shift in their diet from a regime consisting mainly of endotherms with endoskeleton to ectotherms bearing a hard exoskeleton. Maxilla, palatine, pterygoid and dentary teeth were examined in an adult and a juvenile of Dolichophis schmidti, one Eirenis punctolineatus and one Eirenis persicus. 3D Geometric Morphometrics comparison revealed maxilla and palatine teeth of the E. persicus are blunt and conical shape while those teeth are sharp and elongated in E. punctatolineatus as well as the adult and juvenile D. schmidti. A similar difference could be noted for the pterygoid teeth. In contrast, the dentary teeth are not as different among the examined snakes. Blunt and conically shaped teeth, as observed in E. persicus, seem to be more adapted for biting hard bodied, arthropod prey, while sharp and elongated teeth in Dolichophis and E. punctatolineatus, are specialized for puncturing endotherm prey. The results of a finite element analysis confirms that during biting a hard bodied prey, the generated stresses in E. persicus tooth is mostly confined to the tip of the tooth and mostly well below the von Mises yield criterion the tooth. In contrary, D. schmidti tooth appears less well suited for biting a hard prey since the generated stresses widely distribute across the tooth with values roughly 2 to 3 times higher than the von Mises yield criterion of the tooth. A lower degree of specialization that was observed among the dentary teeth in the examined snakes suggest a similar functional constraint in pushing the prey against the upper tooth rows.

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