The biomechanics of the human tongue

Abstract

AcknowledgementsI would like express my gratitude to the following people for their assistance, leading to the successful completion of this work:The invaluable guidance provided by Prof. B. D. Reddy was integral to completing this project.It was an honour and a privilege to have worked with someone with such vast experience, knowledge and wisdom. Throughout my time at Cerecam, he has shown great patience and understanding.Dr. Andrew T. McBride assisted in times of difficulty, even during the most demanding times of his own PhD studies. His generosity, kindness, and outstanding work ethics have been an inspiration.Jean-Paul Pelteret is the person I worked with the most during this project. Without his invaluable assistance, this project could be likened to a Sisyphean task.It was an honour to have worked amongst such an esteemed group of academics at Cerecam. Many lunch hours and tea-breaks discussing everyday issues in a friendly atmosphere has proven fruitful. The geometry of the tongue, and each muscle group of the tongue, are visually identified, and its geometry captured using Mimics [100]. Various image processing tools available in Mimics, such as image segmentation, region-growing and volume generation were used to form the three-dimensional model of the tongue geometry. Muscle fibre orientations were extracted from the same dataset, also using Mimics.The muscle model presented here is based on Hill's three-element model for representation of the constituent parts of muscle fibres. This Hill-type muscle model also draws from recent work in muscle modelling, by Martins [88]. The model is implemented in an Abaqus user element (UEL) subroutine [24]. The transversely isotropic behaviour of the muscle tissue is accounted for, as well as the influence of muscle activation.The mechanics of the model is limited to static, small-strain, anisotropic, linear-elastic behaviour, and the governing equations are suitably linearized. The body position of the patient during an apneic episode is accounted for in the simulations, as well as the effect of gravity. The focus of this study is on tongue muscle behaviour under gravitational loading, simulating a simplified OSA event.Future models will incorporate airway pressure as well. The behaviour of the model is illustrated in a number of benchmark tests, and computational examples.iii

Desempenho funcional da língua na deformidade dentofacial

“…A língua atua diretamente nas funções de sucção, mastigação, deglutição e fala (FELÍCIO, 2004;KAJEE;PELTERET;REDDY, 2013;SOLOMON et al, 2008). Na mastigação, tem o papel de auxiliar a coletar e posicionar o alimento nas faces oclusais (FELÍCIO, 2004).…”

“…A língua é composta por músculos intrínsecos e extrínsecos, apesar da separação entre eles ser difícil para analisar (CAMPOS et al, 2014;KAJEE;PELTERET;REDDY, 2013). Os músculos intrínsecos não se ligam as estruturas vizinhas, e servem para modificar a forma da língua.…”

A physically motivated constitutive model for 3D numerical simulation of skeletal muscles

“…The geometric representation presented here is based on the segmentation proposed in [61]. Other examples aiming at the reconstruction of such tissue structures are presented in literature 557 [20,25,42,64,65]. The masticatory system is reduced to the masseter muscle only because during mastication, the masseter muscle is dominantly responsible for the generation of bite force to be simulated in this example.…”

A visco-hyperelastic constitutive model and its application in bovine tongue tissue

“…The developed FE models intend to improve the understanding of the role of the tongue in linguistics. Kajee et al (2013) developed a linear elastic FE model of the tongue tissue to better understand its actions in the obstructive sleep apnea syndrome. Using an indentation test, Gerard et al (2003) proposed an isotropic hyperelastic model of the tongue to investigate its role in speech production.…”