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Modélisation des tissus mous de la face pour la chirurgie orthognatique assistée par ordinateur

Matthieu Chabanas 1
1 TIMC-GMCAO - Gestes Medico-chirurgicaux Assistés par Ordinateur
TIMC - Techniques de l'Ingénierie Médicale et de la Complexité - Informatique, Mathématiques et Applications, Grenoble - UMR 5525
Abstract : This thesis presents computer-aided methods for planning in orthognatic surgery. This component of he cranio-maxillofacial surgery adresses facial dysmorphosis, corrected by surgical repositioning of the upper and lower jaw. In a first part, a complete computer-assisted protocol for orthognatic surgery is introduced. Special emphasis is given to the definition of a new 3D cephalometry, to study the deformities of the facial skeleton. The main part of this work then addresses the prediction of the changes of morphology resulting from the bone structures repositioning. This is achieved using a biomechanical model of the patient face soft tissues, based on the finite element method. A model specific to each patient must first be created. Due to the constraints in clinical routine, especially time constraints, usual technics for model generation cannot be used. A new method is therefore presented, which consists in conforming a generic model of the face to the morphology of each patient, using CT scans and elastic registration. Results are qualitatively and quantitatively evaluated on seven patients. Once the model is fitted to the patient, aesthetic and functional outcomes of surgical procedures can be simulated. Simple mechanical hypothesis are considered, e.g. linear elasticity and small deformations. A validation protocol is presented to assess the accuracy of the finite element simulations. By comparing pre- and post-operative CT scans, the bone repositioning actually realized during the surgery are measured. These measured displacements are then applied to the patient model to predict the morphological changes. The accuracy of the simulations can therefore be evaluated by comparison with the actual post-operative data. Results are presented for two patients.
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https://tel.archives-ouvertes.fr/tel-00005802
Contributor : Matthieu Chabanas <>
Submitted on : Thursday, April 8, 2004 - 10:13:51 AM
Last modification on : Tuesday, November 24, 2020 - 4:18:04 PM
Long-term archiving on: : Monday, September 20, 2010 - 11:47:57 AM

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  • HAL Id : tel-00005802, version 2

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Matthieu Chabanas. Modélisation des tissus mous de la face pour la chirurgie orthognatique assistée par ordinateur. Sciences du Vivant [q-bio]. Université Joseph-Fourier - Grenoble I, 2002. Français. ⟨tel-00005802v2⟩

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