Development of a biomechanical model for dynamic occlusal stress analysis

Abstract

The use of traditional finite element method (FEM) in occlusal stress analysis is limited due to the complexity of musculature simulation. The present purpose was to develop a displacement boundary condition (DBC)-FEM, which evaded the muscle factor, to predict the dynamic occlusal stress. The geometry of the DBC-FEM was developed based on the scanned plastic casts obtained from a volunteer. The electrognathographic and video recorded jaw positional messages were adopted to analyze the dynamic occlusal stress. The volunteer exhibited asymmetrical lateral movements, so that the occlusal stress was further analyzed by using the parameters obtained from the right-side eccentric movement, which was 6.9 mm long, in the stress task of the left-side eccentric movement, which was 4.1 mm long. Further, virtual occlusion modification was performed by using the carving tool software aiming to improve the occlusal morphology at the loading sites. T-Scan Occlusal System was used as a control of the in vivo detection for the location and strength of the occlusal contacts. Data obtained from the calculation using the present developed DBC-FEM indicated that the stress distribution on the dental surface changed dynamically with the occlusal contacts. Consistent with the T-Scan recordings, the right-side molars always showed contacts and higher levels of stress. Replacing the left-side eccentric movement trace by the right-side one enhanced the simulated stress on the right-side molars while modification of the right-side molars reduced the simulated stress. The present DBC-FEM offers a creative approach for pragmatic occlusion stress prediction.

Effect of changing the direction of the force vector of the mandible in relation to the skull base: study in rabbits

“…Thus, the layers of articular cartilage and the fibrocartilaginous disk can undergo deformations, which are accompanied by internal tissue changes. Therefore, evidence confirms that the mandibular condyle and glenoid fossa have ample capacity for functional adaptation [6,8,9]. Remodeling of the glenoid fossa and compensatory growth of the mandibular condyle adjust with the anatomical position of the condyle in the fossa.…”

“…The temporomandibular joint (TMJ) is a complex synovial articulation. It is growth and development process of the TMJ and its adaptive response to mandibular advancement are known to be notably greater, particularly during the period of accelerated growth, when compared to the glenoid fossa [6,8,10]. However, although the patterns of adaptive responses are different in both structures, they act together in a harmonic manner [11].…”

“…Mandibular movements can be continuous or intermittent, can act alone or in combination, and result from the static and dynamic loading of the TMJ [5,6]. Mechanical loading of the TMJ is necessary for the growth, development, and maintenance of joint tissue.…”

“…The subarticular proliferative zone can support anabolic and catabolic bone remodeling to change the shape and position of the temporal fossa in response to environmental changes [6,8,9]. The role of the condyle in the growth and development process of the TMJ and its adaptive response to mandibular advancement are known to be notably greater, particularly during the period of accelerated growth, when compared to the glenoid fossa [6,8,10]. However, although the patterns of adaptive responses are different in both structures, they act together in a harmonic manner [11].…”

“…Upon completion of growth, the influence of dynamic forces applied to the tissues is maintained by continuous stimulation of apposition and resorption. Mandibular movements can be continuous or intermittent, can act alone or in combination, and result from the static and dynamic loading of the TMJ [5,6].…”