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ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

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FORCE RATIO IN CHEWING MUSCLES AFTER IMPLANTATION A<br />

TOTAL REPLACEMENT OF TMJ<br />

1. ABSTRACT<br />

M. Vilimek 1 and T. Goldmann 2<br />

In this project we study the changes in force ratio after implantation the<br />

temporomandibular joint (TMJ) replacement. During implantation of the artificial<br />

temporomandibular joint must be often removed the temporalis and/or masseter muscle.<br />

In order to perform true loading of temporo-mandibular joint, the loading during<br />

mastication was investigated. Input kinematic variables and mastication force were<br />

experimentally examined. The inverse dynamics approach and static optimization<br />

technique were used for solution of the redundant mechanism. Muscle forces, and<br />

reactions in TMJ were calculated. We modified the model with several different tasks.<br />

The temporalis muscle, masseter muscle or both together were removed and the forces<br />

in chewing muscles and TM joint were newly calculated.<br />

2. INTRODUCTION<br />

The knowledge of temporo-mandibular joint (TMP) reactions and musculotendon<br />

masticatory forces as well as development of realistic musculoskeletal mathematical<br />

model of the system lower jaw-skull is a matter of considerable interest since the<br />

eighties [1]. Those data are important in many medical and scientific fields such as<br />

dentistry, implantology, and biomechanics, because they are necessary for<br />

understanding of bone and joint loading.<br />

During the artificial TMJ implantation, often the surrounding muscles have to be<br />

removed. The most often it is masseter muscle or temporalis muscle or both muscles<br />

together. This removing is cause of the TMJ implantation technology. This study<br />

analysis what will happen with muscular forces and loading distribution in TMJ after<br />

removing of these muscles. In case of increasing loading we must respect these forces<br />

during dimensioning of artificial TMJ. The main goal of this study is to investigate the<br />

sensitivity of load distribution after removing some muscles.<br />

3. METHODS<br />

The mathematical 3D model of mandible and skull including 16 actuators for two<br />

temporo-mandibular (TM) joints was created as first. These actuators included two parts<br />

of masseter (deep and surface), two parts of temporalis (anterior and posterior), two<br />

parts of pterygoideus medialis (anterior and posterior) and two parts of pterygoideus<br />

1 Research Assistant, Czech Technical <strong>University</strong> in Prague, Faculty of Mechanical Engineering,<br />

Department of mMechanics, Biomechjanics and Mechatronics, Technicka 4, 16607, Prague, CZ<br />

2 Research Assistant, Czech Technical <strong>University</strong> in Prague, Faculty of Mechanical Engineering,<br />

Department of mMechanics, Biomechjanics and Mechatronics, Technicka 4, 16607, Prague, CZ

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