scholarly journals Evaluation of the Effects of the Dental and Skeletal Anchored Face Mask Therapies on the Craniofacial System by Using Nonlinear Finite Element Analysis

2017 ◽  
Vol 7 ◽  
pp. 267-272
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armağan Fatih Karamanli

Aims The aim of this study was to evaluate the biomechanical effects on the craniofacial complex of skeletal anchorage and dental anchorage during face mask therapy. Subjects and Methods Two nonlinear finite element (FE) simulations were performed using a three-dimensional FE model. Face mask therapy with dental anchorage in the upper canines and face mask therapy with skeletal anchorage in the piriform apertures of the maxilla were simulated. In both simulations, the magnitude of the applied force was 750 g per side, and the force direction was 30° forward and downward relative to the occlusal plane. Results The circummaxillary sutures showed greater and more uniform stresses in the skeletal anchorage model than the dental anchorage model. This is the result of the more parallel forward movement of the maxilla in the skeletal anchorage model. Conclusions In Class III malocclusions with maxillary deficiency, for improved effects on the maxilla, choosing skeletal anchorage may be more effective in face mask therapies

2017 ◽  
Vol 7 ◽  
pp. 219-223
Author(s):  
Beril Demir Karamanli ◽  
Hülya Kılıçoğlu ◽  
Armagan Fatih Karamanli

Aims The aim of this study is to evaluate the effects of the chincup appliance used in the treatment of Class III malocclusions, not only on the mandible or temporomandibular joint (TMJ) but also on all the craniofacial structures. Materials and Methods Chincup simulation was performed on a three-dimensional finite element (FE) model. 1000 g (500 g per side) force was applied in the direction of chin-condyle head. Nonlinear FE analysis was used as the numerical analysis method. Results By the application of chincup, stresses were distributed not only on TMJ or mandible but also on the circummaxillary sutures and other craniofacial structures. Conclusions Clinical changes obtained by chincup treatment in Class III malocclusions are not limited by only mandible. It was seen that also further structures were affected.


Author(s):  
Muhammed Hilmi Buyukcavus ◽  
Burak Kale

Abstract Aim: To compare the two different skeletal anchorage methods with finite element analysis in the treatment of Class III patients with maxillary retrognathia. Material and Methods: Two different treatment scenarios were performed on the skull model obtained from computerized tomography images of skeletal Class III patients with maxillary retrognathia and finite element analysis was performed. In the first group; mini plates were simulated on the infra zygomatic crest. A unilateral 500 g protraction force was applied to the face-mask. In the second group; mini plates were simulated in the infrazigomatic crest and mandibular symphysis. Then, 500g protraction force was applied with Class III elastic between the miniplates. Von Misses stresses and displacement values were evaluated comparatively. Results: In the Class III elastic group, maximum Von Misses stress occurred around the infra zygomatic crest and symphysis anchored with 0.078MPa. The maxillary posterior region and paranasal regions were the areas that showed the highest Von Misses tension after infra zygomatic crest and symphysis. In the face-mask group, the most common site of Von Misses stress in the nasomaxillary complex and alveolar structures were the infra zygomatic area where plaques were applied, followed by pterygomaxillary suture. Tensile forces are reduced especially in these two areas by spreading to the surrounding structures. Conclusion: In both methods, it was determined that the amount of force transmitted to the circumaxillary sutures was sufficient to induce the formation of osteogenesis in these regions. Keywords: skeletal anchorage, Class III malocclusion, finite element analysis. Continuous...


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ryo Hamanaka ◽  
Daniele Cantarella ◽  
Luca Lombardo ◽  
Lorena Karanxha ◽  
Massimo Del Fabbro ◽  
...  

Abstract Background The aim of this study is to compare the biomechanical effects of the conventional 0.019 × 0.025-in stainless steel archwire with the dual-section archwire when en-masse retraction is performed with sliding mechanics and skeletal anchorage. Methods Models of maxillary dentition equipped with the 0.019 × 0.025-in archwire and the dual-section archwire, whose anterior portion is 0.021 × 0.025-in and posterior portion is 0.018 × 0.025-in were constructed. Then, long-term tooth movement during en-masse retraction was simulated using the finite element method. Power arms of 8, 10, 12 and 14 mm length were employed to control anterior torque, and retraction forces of 2 N were applied with a direct skeletal anchorage. Results For achieving bodily movement of the incisors, power arms longer than 14 mm were required for the 0.019 × 0.025-in archwire, while between 8 and 10 mm for the dual-section archwire. The longer the power arms, the greater the counter-clockwise rotation of the occlusal plane was produced. Frictional resistance generated between the archwire and brackets and tubes on the posterior teeth was smaller than 5% of the retraction force of 2 N. Conclusions The use of dual-section archwire might bring some biomechanical advantages as it allows to apply retraction force at a considerable lower height, and with a reduced occlusal plane rotation, compared to the conventional archwire. Clinical studies are needed to confirm the present results.


2012 ◽  
Vol 215-216 ◽  
pp. 847-850
Author(s):  
Shou Jun Wang ◽  
Xing Xiong ◽  
Hong Jie Wang

In the condition of alternating impact ,the nut-supports subassembly is analyzed according to uncertainty of design parameters. Firstly, a three-dimensional (3-D) finite element (FE) model of the nut-supports subassembly is built and is meshed,and the constraints and loads are imposed.Secondly,the model of nut-supports was assembled using the software ANSYS to understand the stress distribution and various parts of the deformation of the nut-supports and its weak links in the harmonic forces.Finally,socket head cap screw has not enough pre-load in the condition of alternating impact and will be simplified.It is analyzed and checked whether it is cut or not; which provides the reference data for design and optimization of the wave maker.


2012 ◽  
Vol 201-202 ◽  
pp. 741-744 ◽  
Author(s):  
Zhen Ning Hou ◽  
Jun Wu ◽  
Qing Wang ◽  
Hong Gen Tian ◽  
Nan Chao ◽  
...  

A finite element approach based on Ansys is developed to simulate stress intensity distribution in a three dimensional model of coupling clamp joint, which includes ferrules, pipe caps and bolts. The characteristics of stress intensity distributions of coupling clamp joint under strength pressure loading have been studied by means of the non-linear finite element method. The FE model can also predict the clamp quality and tolerances to be expected under different process conditions and define the most effective process parameters to influence the tolerances. The study could give us a better understanding on the mechanism and basis for optimization design of the coupling clamp joint.


Author(s):  
Sung Jin Yoon ◽  
Tae Jin Shin ◽  
Jae Sang Lee ◽  
Sang Moo Hwang

This paper describes in detail the deformation behavior of the rolls and strip predicted from the three-dimensional finite element analysis of skin-pass rolling. The predictions are made on the basis of the coupled analysis of elastic deformation of the rolls and elastic–plastic deformation of the strip. Predictions from the proposed finite element (FE) model are compared with experimental data from laboratory-scale cold rolling mills. Then, proposed are models for the prediction of the roll force profile and for the prediction of the residual stress profile. The prediction accuracy of the models is examined through comparison with the predictions from the FE model.


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