Effect of Occlusal Splints on the Stress Distribution on the Temporomandibular Joint Disc

Abstract

Conservative approach, including occlusal splint therapy, is the first option to treat temporomandibular disorders (TMD), because of its reversibility. The present study analyzed the effect of the articular disc position and occlusal splints use on the stress distribution on this disc. A two-dimensional (2D) finite element (FE) model of the temporomandibular joint with the articular disc at its physiologic position was constructed based on cone-beam computed tomography. Three other FE models were created changing the disc position, according to occlusal splint use and anterior disc displacement condition. Structural stress distribution analysis was performed using Marc-Mentat package. The equivalent von Mises stress was used to compare the study factor. Higher stress concentration was observed on the intermediate to anterior zone of the disc, with maximum values over 2MPa. No relevant difference was verified on the stress distribution and magnitude comparing disc positions and occlusal splint use. However, there was stress reduction arising from the use of the occlusal splints in cases of anterior disc displacement. In conclusion, based on the generated FE models and established boundary conditions, the stress increased at the intermediate zone of the TMJ disc during physiological mandible closure. The stress magnitude was similar in all tested situations

Finite element analysis of occlusal splint therapy in patients with bruxism

“…The 3D models of the samples were standardized in terms of defining the x, y, and z axis with respect to the same reference in order to ensure the correct loading distribution for comparing the biomechanical parameters of the models with each other. Table 1 shows the material properties considered for jaw bones, teeth, and splints [20,42]. One of the most important points in FE analysis is how different parts of the model interact with each other.…”

“…In this study, these interactions and constraints were defined based on the actual anatomical function of these components in human body. The constraint considered for the contact between the inserted teeth on the upper and lower jaws with splint was a surface-to-surface constraint with a friction coefficient of 0.5 [20]. The degree of freedom of the upper surface of maxilla was considered to be zero at all three directions of x, y and z, i. e., the surface was considered to be fixed.…”

“…According to a previous study, a first order Ogden hyperelastic model was used for defining the periodontal ligament with a Poisson's ratio of 0.45 and the material parameter μ = 0.0025 MPa [43]. The average force exerted by the medial pterigoid muscle and masseter muscle for both of the left and right muscles was assumed to be 50 N [20,42]. It should be noted that, according to previous studies, the force of these muscles should be applied under a particular angle to the model, as shown in Fig.…”

“…The second group of studies has focused on the assessment of treatments of TMJ disorders. Ferreira et al showed how the occlusal splint distributes stress in TMJ disc [20]. Salmi et al found a new digital process to produce occlusal splints in a study using a laser scanner and evaluated the effectiveness of this new production method [21].…”

An Innovative Protocol Of Physiokinetotherapy For The Treatment Of Temporomandibular Disorder

“…This fact has a very big significance in order to preserve the health of the stomatognathic system and also to avoid the alterations of the articular disc that may lead to the appearance of temporomandibular disorders (TMDs). (Ferreira, Simamoto-Júnior, Soares, Ramos, & Fernandes-Neto, 2017) The TMDs are as well called craniomandibular disorders and comprise a class of pathologies that alter the masticatory muscles, the temporomandibular joint and also the structures related to it. This type of disorders affects a percentage of more than 25% of the general population (McNeely, Armijo Olivo, & Magee, 2006;McNeill, 1993;Di Fabio, 1998;Gremillion, 2000).…”