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Byte your tongue : a computational model of human mandibular-lingual biomechanics for biomedical applications Stavness, Ian Kent

Abstract

Biomechanical models provide a means to analyze movement and forces in highly complex anatomical systems. Models can be used to explain cause and effect in normal body function as well as in abnormal cases where underlying causes of dysfunction can be clarified. In addition, computer models can be used to simulate surgical changes to bone and muscle structure allowing for prediction of functional and aesthetic outcomes. This dissertation proposes a state-of-the-art model of coupled jaw-tongue-hyoid biomechanics for simulating combined jaw and tongue motor tasks, such as chewing, swallowing, and speaking. Simulation results demonstrate that mechanical coupling of tongue muscles acting on the jaw and jaw muscles acting on the tongue are significant and should be considered in orofacial modeling studies. Towards validation of the model, simulated tongue velocity and tongue-palate pressure are consistent with published measurements. Inverse simulation methods are also discussed along with the implementation of a technique to automatically compute muscle activations for tracking a target kinematic trajectory for coupled skeletal and soft-tissue models. Additional target parameters, such as dynamic constraint forces and stiffness, are included in the inverse formulation to control muscle activation predictions in redundant models. Simulation results for moving and deforming muscular-hydrostat models are consistent with published theoretical proposals. Also, muscle activations predicted for lateral jaw movement are consistent with published literature on jaw physiology. As an illustrative case study, models of segmental jaw surgery with and without reconstruction are developed. The models are used to simulate clinically observed functional deficits in movement and bite force production. The inverse simulation tools are used to predict muscle forces that could theoretically be used by a patient to compensate for functional deficits following jaw surgery. The modeling tools developed and demonstrated in this dissertation provide a foundation for future studies of orofacial function and biomedical applications in oral and maxillofacial surgery and treatment.

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Attribution-NonCommercial-NoDerivatives 4.0 International