Consequences of Viscoelastic Behavior in the Human Temporomandibular Joint Disc

• Published in: Journal of dental research Vol. 86; no. 12; pp. 1198 - 1202
• Main Authors: Koolstra, J.H., van Eijden, T.M.G.J.
• Format: Journal Article
• Language: English
• Published: United States SAGE Publications 01.12.2007; SAGE PUBLICATIONS, INC
• Subjects: Cartilage, Articular - physiology; Computer Simulation; Dental Models; Dental Stress Analysis; Dentistry; Elasticity; Finite Element Analysis; Humans; Mastication - physiology; Models, Anatomic; Range of Motion, Articular - physiology; Temporomandibular Joint Disc - physiology; Viscosity; articular disc; temporomandibular joint; Finite Element modeling; viscoelasticity
• ISSN: 0022-0345; 1544-0591
• DOI: 10.1177/154405910708601211

The consequences of the viscoelastic behavior of the temporomandibular joint disc were analyzed in simulated jaw open-close cycles. It was hypothesized that viscoelasticity helps protect the underlying bone, while augmenting the smoothness of articular movements. Simulations were performed with a dynamic model of the masticatory system, incorporating the joints’ cartilaginous structures as Finite Element Models. A non-linear viscoelastic material model was applied for the disc. The apparent stiffness of the disc to principal stress was largest when the jaw was closed, whereas, with the Von Mises’ stress, it appeared largest when the jaw was open. The apparent stiffnesses appeared to be dependent on both the speed of the movements and the presence of a resistance between the teeth. It was concluded that the disc becomes stiffer when load concentrations can be expected. During continued cyclic motion, it softens, which favors smoothness of joint movement at the cost of damage prevention.