Three-dimensional finite element analysis of the human temporomandibular joint disc (original) (raw)
Related papers
Journal of dental research, 2001
While the movability of the human temporomandibular joint is great, the strains and stresses in the cartilaginous structures might largely depend on the position of the mandible with respect to the skull. This hypothesis was investigated by means of static three-dimensional finite element simulations involving different habitual condylar positions. Furthermore, the influence of several model parameters was examined by sensitivity analyses. The results indicated that the disc moved together with the condyle in the anterior direction without the presence of ligaments and the lateral pterygoid muscle. By adapting its shape to the changing geometry of the articular surfaces, the disc prevented small contact areas and thus local peak loading. In a jaw-closed configuration, the influence of 30 degrees variations of the loading direction was negligible. The load distribution capability of the disc appeared to be proportional to its elasticity and was enhanced by the fibrocartilage layers o...
Tensile stress patterns predicted in the articular disc of the human temporomandibular joint
Journal of Anatomy, 2009
The direction of the first principal stress in the articular disc of the temporomandibular joint was predicted with a biomechanical model of the human masticatory system. The results were compared with the orientation of its collagen fibers. Furthermore, the effect of an active pull of the superior lateral pterygoid muscle, which is directly attached to the articular disc, was studied. It was hypothesized that the markedly antero-posterior direction of the collagen fibers would be reflected in the direction of the tensile stresses in the disc and that active pull of the superior lateral pterygoid muscle would augment these tensions. It was found that the tensile patterns were extremely dependent on the stage of movement and on the mandibular position. They differed between the superior and inferior layers of the disc. The hypothesis could only be confirmed for the anterior and middle portions of the disc. The predicted tensile principal stresses in the posterior part of the disc alternated between antero-posterior and medio-lateral directions.
Stress analysis of the human temporomandibular joint
Medical Engineering & Physics, 1998
Stress analysis of the human temporomandibular joint (TMJ) consisting of mandibular disc, condyle and fossa-eminence complex during normal sagittal jaw closure was performed using non-linear finite element analysis (FEA). The geometry of the TMJ was obtained from magnetic resonance imaging (MRI). The tissue proportion was measured from a cadaver TMJ. Contact surfaces were defined to represent the interaction between the mandibular disc and the condyle, and between the mandibular disc and the fossaeminence complex so that finite sliding was allowed between contact bodies. Stresses in the TMJ components (disc, condyle and fossa-eminence complex), and forces in capsular ligaments were obtained. The results demonstrated that, with the given condylar displacement, the stress in the condyle was dominantly compressive and in the fossa-eminence complex was dominantly tensile. The cancellous bone was shielded by the shell shaped cortical bone from the external loading. The results illustrate the stress distributions in the TMJ during a normal jaw closure.
Prediction of volumetric strain in the human temporomandibular joint cartilage during jaw movement
Journal of Anatomy, 2006
Human temporomandibular joint loading causes pressurization and flow of interstitial fluid in its cartilaginous structures. This largely determines its load-bearing and maintenance capacity. It was hypothesized that during cyclical jaw movements normal pressure distribution dynamics would enable fluid to reach all necessary cartilage regions. This was tested qualitatively by analysis of local volumetric strain dynamics during jaw open-close movements predicted by a dynamic model of the human masticatory system. Finite-element analysis was performed in separate regions of the articular cartilage layers and articular disc. Heterogeneous patterns of dilatation and compression were predicted. Compression was found to be more dominant during jaw closing than opening. The pressure gradient in the superior layer of the articular disc was more mediolaterally orientated than in its inferior layer. The findings suggest that, where necessary, regionally the cartilage can imbibe fluid to protect the subchondral bone from impact loads effectively. In the disc itself presumably all areas receive regular refreshment of interstitial fluid.
European Journal of Oral Sciences, 2006
In the temporomandibular joint (TMJ), overloading induced by prolonged clenching appears to be important in the cascade of events leading to disc displacement. In this study, the effect of disc displacement on joint stresses during prolonged clenching was studied. For this purpose, finite-element models of the TMJ, with and without disc displacement, were used. Muscle forces were used as a loading condition for stress analysis during a time-period of 10 min. The TMJ disc and connective tissue were characterized as a linear viscoelastic material. In the asymptomatic model, large stresses were found in the central and lateral part of the disc through clenching. In the retrodiscal tissue, stress relaxation occurred during the first 2 min of clenching. In the symptomatic model, large stresses were observed in the posterior part of the disc and in the retrodiscal tissue, and the stress level was kept constant through clenching. This indicates that during prolonged clenching the disc functions well in the asymptomatic joint, meanwhile the retrodiscal tissue in the symptomatic joint is subject to excessive stress. As this structure is less suitable for bearing large stresses, tissue damage may occur. In addition, storage of excessive strain energy might lead to breakage of the tissue.
Journal of cranio-maxillo-facial surgery : official publication of the European Association for Cranio-Maxillo-Facial Surgery, 2014
To investigate the influence of unilateral disc displacement (DD) in the temporomandibular joint (TMJ) on the stress in the contralateral joint, with a normally-positioned disc, during clenching. A finite element model of the TMJ was constructed based on MRI and 3D-CT of a single patient with a unilateral DD. A second model with bilateral normally-positioned discs served as a reference. The differences in stress distribution in various TMJ components during clenching were predicted with these models. In the unaffected joint of the unilateral DD model, the largest von Mises stress at the start of clenching was predicted in the inferior surface of the disc and increased by 30% during clenching. In the connective tissue the largest stress (1.16 MPa) did not reduce during clenching, in contrast to the (unaffected) joints of the reference model. In the affected joint, the largest stress was predicted in the temporal cartilage throughout clenching. In the surrounding connective tissue, th...
2010
er, stress-intensity factors and load-line displacements have been calculated for chevron-notched bar and rod fracture specimens using a three-dimensional finite-element analysis. simulated wedge loading (either uniform applied displacement or uniform applied load). straight. Crack-length-to-specimen width ratios (a/w) ranged from 0.4 to 0.7. The width-to-thickness ratio (w/B) was 1.45 or 2. Both specimens were subjected to The chevron-notch sides and crack front were assumed to be The bar specimens had a height-to-width ratio of 0.435 or 0.5. of singularity elements around the crack front and 8-noded isoparametric elements elsewhere. intensity factors were calculated by using a nodal-force method for distribution along the crack front and by using a compliance method for average values. sented and compared with expe imental solutions. from the literature. stress-intensity factors and load-line displacements were about 2.5 and 5 percent lower than the reported experimental values, respectively. Finite-element models were composed The models had about 11,000 degrees of freedom. Stress-The stress-intensity factors and load-line displacements are pre-The 'Senior Scientist, Vigyan Research Associates, Hampton, VA 23666. Work 'Senior Scientist, NASA Langley Research Center, Hampton, VA 23665. performed under NASA contract NASI-17090.
Dynamic Properties of the Human Temporomandibular Joint Disc
Journal of Dental Research, 2001
The cartilaginous intra-articular disc of the human temporomandibular joint shows clear anteroposterior variations in its morphology. However, anteroposterior variations in its tissue behavior have not been investigated thoroughly. To test the hypothesis that the mechanical properties of fresh human temporomandibular joint discs vary in anteroposterior direction, we performed dynamic indentation tests at three anteroposteriorly different locations. The disc showed strong viscoelastic behavior dependent on the amplitude and frequency of the indentation, the location, and time. The resistance against deformations and the shock absorbing capabilities were larger in the intermediate zone than in regions located more anteriorly and posteriorly. Because several studies have predicted that the intermediate zone is the predominantly loaded region of the disc, it can be concluded that the topological variations in its tissue behavior enable the disc to combine the functions of load distribution and shock absorption effectively.
International Journal for Numerical Methods in Biomedical Engineering, 2020
Temporomandibular joints (TMJs) constitute a pair of joints that connect the jawbone to the skull. TMJs are bilateral joints which work as one unit in conducting daily functions such as speaking, mastication, and other activities associated with the movement of the jaw. Issues associated with the TMJs may arise due to various factors-one such factor being the internal load on the TMJ. These issues may contribute to temporomandibular disorders (TMD). This study aims to evaluate the mandibular trajectories and the associated stress changes during the process of opening the mouth on the TMJs of an asymptomatic subject. The mouth opening motion was recorded by a motion capturing system using models of the mandible and maxilla constructed based on the computed tomography (CT). Two discs constructed based on magnetic resonance imaging (MRI). Finite element analysis was performed on the relative motion of the mandible to the maxilla and validated. The process modelled by these displacements provided less than 10% error in terms of deformation. The simulation results indicate that the lateral intermediate zone-the head and neck of the mandible-and the articular eminence sustained the most significant stresses during the mouth opening motion. The results also suggested that the stresses This article is protected by copyright. All rights reserved. increase as the range of opening increases with the greatest von Mises stress, tensile, and compressive stress found at the position of maximal opening.