scholarly journals A Three-Dimensional Finite Element Analysis of Displacement and Stress Distributions of Unilateral and Bilateral Cleft Lips by Using Developed Pre-Surgical Treatment Architecture

Children ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 1121
Author(s):  
Ali A. H. Karah bash ◽  
Ergun Ercelebi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Surgical Treatment ◽  
Three Dimensional ◽  
Surgical Techniques ◽  
Control Unit ◽  
External Stress ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Element Analysis

Cleft lips and cleft palates are the most common birth defects in newborns. Pre-surgical correction of unilateral and bilateral cleft lips and palates has been the subject of interest of many previous works. This condition has necessitated the evolution of many surgical and non-surgical techniques to mitigate the problem of this deformity in children. In this study, we proposed a new architecture that can be used instead of the conventional pre-surgical treatment. The proposed architecture has mechanical and electronic parts. This architecture was adopted to apply external stress to the cleft bones and cleft edges using an airbag that is located in the mechanical part. The amount of air in the airbag can be controlled by an available control unit in the electronic part. The effect of external stress on the cleft bones and the cleft edges was analyzed by using the finite element analysis (FEA) method. The FEA study aimed to analyze the displacement, amount of tensile and compressive forces, and Von Mises stress distributions on the cleft bones, cleft edges, nasal septum, and superior alveolar part of the maxillary jaw of unilateral and bilateral cleft models during pre-surgical treatment with the novel architecture. The results show that displacement and stress affected the clefts of both models. Displacement had a significant effect of gradually bringing the clefts closer to each other and returning them to the posterior. The analysis also investigated the effects of stress on the cleft bone and cleft edge. It was found from the results that the stresses helped to bring the incisions closer to the most appropriate position for plastic surgeons. The results prove that the positive and negative X-displacements move in the opposite direction, which means that the cleft edges gradually converge toward each other. Moreover, the negative Z-displacement affected the movement of cleft bones and cleft edges from outside to inside and gradually returned them to a suitable position. The findings show that the proposed architecture can be contributed to the pre-surgical treatment of the unilateral and bilateral clefts as an alternative to the traditional method.

scholarly journals Comparison of Tooth- and Bone-Borne Appliances on the Stress Distributions and Displacement Patterns in the Facial Skeleton in Surgically Assisted Rapid Maxillary Expansion—A Finite Element Analysis (FEA) Study

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1152
Author(s):  
Rafał Nowak ◽  
Anna Olejnik ◽  
Hanna Gerber ◽  
Roman Frątczak ◽  
Ewa Zawiślak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Rapid Maxillary Expansion ◽  
Stress Distributions ◽  
Maxillary Expansion ◽  
Facial Skeleton ◽  
Element Analysis ◽  
Maxillary Constriction

The aim of this study was to compare the reduced stresses according to Huber’s hypothesis and the displacement pattern in the region of the facial skeleton using a tooth- or bone-borne appliance in surgically assisted rapid maxillary expansion (SARME). In the current literature, the lack of updated reports about biomechanical effects in bone-borne appliances used in SARME is noticeable. Finite element analysis (FEA) was used for this study. Six facial skeleton models were created, five with various variants of osteotomy and one without osteotomy. Two different appliances for maxillary expansion were used for each model. The three-dimensional (3D) model of the facial skeleton was created on the basis of spiral computed tomography (CT) scans of a 32-year-old patient with maxillary constriction. The finite element model was built using ANSYS 15.0 software, in which the computations were carried out. Stress distributions and displacement values along the 3D axes were found for each osteotomy variant with the expansion of the tooth- and the bone-borne devices at a level of 0.5 mm. The investigation showed that in the case of a full osteotomy of the maxilla, as described by Bell and Epker in 1976, the method of fixing the appliance for maxillary expansion had no impact on the distribution of the reduced stresses according to Huber’s hypothesis in the facial skeleton. In the case of the bone-borne appliance, the load on the teeth, which may lead to periodontal and orthodontic complications, was eliminated. In the case of a full osteotomy of the maxilla, displacements in the buccolingual direction for all the variables of the bone-borne appliance were slightly bigger than for the tooth-borne appliance.

Mechanical and Optimization Analyses for Novel Wound Composite Axial Impeller

2009 ◽  
Author(s):  
Jifeng Wang ◽  
Qubo Li ◽  
Norbert Mu¨ller
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Speed ◽  
High Performance ◽  
Low Cost ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Loading Conditions ◽  
Element Analysis ◽  
Wound Composite

A mechanical and optimal analyses procedure is developed to assess the stresses and deformations of Novel Wound Composite Axial-Impeller under loading conditions particular to centrifuge. This procedure is based on an analytical method and Finite Element Analysis (FEA, commercial software ANSYS) results. A low-cost, light-weight, high-performance, composite turbomachinery impeller from differently designed patterns will be evaluated. Such impellers can economically enable refrigeration plants using water as a refrigerant (R718). To create different complex patterns of impellers, MATLAB is used for creating the geometry of impellers, and CAD software UG is used to build three-dimensional impeller models. Available loading conditions are: radial body force due to high speed rotation about the cylindrical axis and fluid forces on each blade. Two-dimensional plane stress and three-dimensional stress finite element analysis are carried out using ANSYS to validate these analytical mechanical equations. The von Mises stress is investigated, and maximum stress and Tsai-Wu failure criteria are applied for composite material failure, and they generally show good agreement.

Investigation on stress distribution and pressure capacity of two-layer split high-pressure die based on finite element analysis

2019 ◽  
Vol 233 (14) ◽  
pp. 5048-5055
Author(s):  
Z Yi ◽  
WZ Fu ◽  
MZ Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Pressure ◽  
Stress State ◽  
Von Mises Stress ◽  
Stress Distributions ◽  
Element Analysis ◽  
Round Cylinder ◽  
Von Mises ◽  
Supporting Ring

In order to obtain a higher pressure capacity for the high-pressure die with a larger sample cavity, two types of two-layer split dies with a round cylinder and a quadrate cylinder were designed based on the conventional belt-type die. Finite element analysis was performed to investigate the stress distributions and pressure capacities of the high-pressure dies using a derived Mohr–Coulomb criterion and the von Mises criterion for the cylinder and supporting rings, respectively. As predicted by the finite element analysis results, in the two-layer split dies with a round cylinder, the stress state of the cylinder can be only slightly improved; and the von Mises stress of the first layer supporting ring can be hardly decreased. However, in the two-layer split dies with a quadrate cylinder and sample cavity, the stress state of the cylinder can be remarkably improved. Simultaneously, the von Mises stress of the supporting rings, especially for the first-layer supporting ring, can be also effectively decreased. The pressure capacities of the two-layer split dies with a round cylinder and a quadrate cylinder are 16.5% and 63.9% higher with respect to the conventional belt-type die.

scholarly journals The Effect of the Length and Distribution of Implants for Fixed Prosthetic Reconstructions in the Atrophic Posterior Maxilla: A Finite Element Analysis

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2556
Author(s):  
Brunilda Cenkoglu ◽  
Nilufer Balcioglu ◽  
Tayfun Ozdemir ◽  
Eitan Mijiritsky
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Minimum Principle ◽  
Three Dimensional ◽  
Surgical Techniques ◽  
Dental Arch ◽  
Element Analysis ◽  
The Maximum Principle ◽  
Posterior Maxilla ◽  
Atrophic Maxilla

In this study, different prosthetic designs that could be applied instead of advanced surgical techniques in atrophic maxilla were evaluated with finite element analysis. Atrophic posterior maxilla was modeled using computer tomography images and four models were prepared as follows: Model 1 (M1), two implants supporting a three-unit distal cantilever prosthesis; Model 2 (M2), two implants supporting a three-unit conventional fixed partial denture; Model 3 (M3), three implants supporting three connected crowns; and Model 4 (M4), two implants supporting two connected crowns. Implants 4 mm in width and 8 mm or 13 mm in length were used. A linear three-dimensional finite element programme was used for analysis. The maximum principle stress (tensile) and minimum principle stress (compressive) were used to display stress in cortical and cancellous bones. The von Mises criteria were used to evaluate the stress on the implants. M1 was found to be the most risky model. The short dental arch case (M4) revealed the lowest stresses among the models but is not recommended when one more implant can be placed because of the bending forces that could occur at the mesial implant. In M2 and M3, the distal implants were placed bicortically between the crestal and sinus cortical plates, causing a fall of the stresses because of the bicortical stability of these implants.

A comparative study between zirconia and titanium abutments on the stress distribution in parafunctional loading: A 3D finite element analysis

2020 ◽  
Vol 28 (6) ◽  
pp. 603-613 ◽  
Author(s):  
Efe Can Sivrikaya ◽  
Mehmet Sami Guler ◽  
Muhammed Latif Bekci
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Principal Stresses ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
3D Fea ◽  
Von Mises ◽  
Three Dimensional Finite Element

BACKGROUND: Zirconia has become a popular biomaterial in dental implant systems because of its biocompatible and aesthetic properties. However, this material is more fragile than titanium so its use is limited. OBJECTIVES: The aim of this study was to compare the stresses on morse taper implant systems under parafunctional loading in different abutment materials using three-dimensional finite element analysis (3D FEA). METHODS: Four different variations were modelled. The models were created according to abutment materials (zirconia or titanium) and loading (1000 MPa vertical or oblique on abutments). The placement of the implants (diameter, 5.0 × 15 mm) were mandibular right first molar. RESULTS: In zirconia abutment models, von Mises stress (VMS) values of implants and abutments were decreased. Maximum and minimum principal stresses and VMS values increased in oblique loading. VMS values were highest in the connection level of the conical abutments in all models. CONCLUSIONS: Using conical zirconia abutments decreases von Mises stress values in abutments and implants. However, these values may exceed the pathological limits in bruxism patients. Therefore, microfractures may be related to the level of the abutment.

Three-Dimensional Modeling and Finite Element Analysis of an Ankle External Fixator

2020 ◽  
Vol 899 ◽  
pp. 94-102
Author(s):  
Nur Faiqa Ismail ◽  
Muhammmad Aiman Firdaus Bin Adnan ◽  
Solehuddin Shuib ◽  
Nik Ahmad Hambali Nik Abd Rashid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
External Fixator ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
External Fixators ◽  
Element Analysis ◽  
Stress And Deformation ◽  
The Stability ◽  
Von Mises

External fixator has played an important role in repairing fractured ankle bone. This surgery is done due to the several factors which are the bone is not normal position or has broken into several pieces. The external fixator will help the broken bone to grow and remodel back to the original appearance. However, there are some issues regarding to the stability of this fixation. Improper design and material are the major factor that decreased the stability since it is related to the deformation of the external fixator to hold the bone fracture area. This study aims to design a stable structure for constructing delta frame ankle external fixator to increase the stability of the fixation. There are two designs of external fixator with two types of material used in this present study. Both external fixators with different materials are analyzed in terms of von Mises stress and deformation by using a conventional Finite Element Analysis software; ANSYS Workbench V15. The result obtained shows the Model 1 with stainless steel has less stress and deformation distributions compared to the Model 2. Hence, by using Model 1 as the external fixator, the stability of the fixation can be increased.

scholarly journals To Evaluate the Influence of Different Implant Thread Designs on Stress Distribution of Osseointegrated Implant: A Three-Dimensional Finite-Element Analysis Study–An In Vitro Study

2020 ◽  
Vol 08 (01) ◽  
pp. 09-16
Author(s):  
Chhavi Sharma ◽  
Tarun Kalra ◽  
Manjit Kumar ◽  
Ajay Bansal ◽  
Anupreet Kaur Chawla
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Axial Load ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Element Analysis ◽  
Osseointegrated Implant ◽  
Implant Therapy ◽  
Von Mises ◽  
Selection Of

Abstract Introduction Dental implants are common treatment modality for tooth loss which leads to unaesthetic appearance and may also cause deterioration of mastication and speech. The aim of implant therapy in dentistry is to restore tissue contour, function, comfort, aesthetic, and speech. Dental implant role is to transfer the mechanical force created during chewing to the supporting osseous tissues within the mandible and maxilla. The importance of biomechanical factors such as the bone-implant interface, implant thread design, the length and diameter of implants, type of loading, the quality and quantity of surrounding bone have been strained by various authors. The selection of implant thread design plays an important role in the outcome of the treatment. This study was done to evaluate the influence of different thread designs on stress distribution of osseointegrated implant using three-dimensional (3D) finite-element analysis. Materials and Methods Three implants with different thread designs, namely V-thread, buttress, and reverse buttress thread designs were considered and dimensions were standardized. The site considered was the mandibular molar region with cortical and cancellous bone assuming to be isotropic and homogeneous. The implant modeling was done with the ANSYS 18.1 software. Axial load (100N) and buccolingual load (50N) were applied. The stresses were calculated as Von Mises stress criterion. Results Minimum von mises Stress concentration was seen for tapered implant body with reverse buttress thread design under axial load 100N and tapered implant body with V-thread under buccolingual load of 50N at cortical bone which signifies bone preservation. Stress levels were observed maximum at implant and minimum at the cancellous bone. Conclusion Hence, within the limitations of this study the results obtained can be applied clinically for appropriate selection of implant thread design for a predictable success of implant therapy.

The Reliability Evaluation of Threaded Connections in Challenging Drilling by Three-Dimensional Finite Element Analysis

2013 ◽  
Vol 690-693 ◽  
pp. 2831-2839 ◽  
Author(s):  
Feng Chen ◽  
Qin Feng Di ◽  
Wen Chang Wang ◽  
Wei Ping Zhu ◽  
Ming Jie Wang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Reliability Evaluation ◽  
Von Mises Stress ◽  
Deep Drilling ◽  
Element Analysis ◽  
Threaded Connections ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The development of ultra-deep drilling and extended reach drilling present many critical challenges for the threaded connections. The reliability of threaded connections must be evaluated to ensure the structural and sealing integrity of drillstring in critical applications. Three-dimensional finite element analysis of threaded connections has been performed in this paper. Different types of loading composed of make-up torque, working torque, tension and bending loading are applied to the model. The makeup characteristics of threaded connections have been analyzed, and the reliability of threaded connections under severe conditions has been evaluated. The results show that von Mises stress distribution over threaded connections is highly uneven, tooth nearby two ends was bearing the most of load. It shows that ultra-deep drilling case is even more challenge than extend reach drilling case in the threaded connections, the reliability evaluation of threaded connections is important in those challenging drilling.

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