La qualité d’une prise de vue est un point incontournable dans la résolution des problèmes d’imagerie. Un capteur non adapté, un éclairage non contrôlé, ou des conditions variables de la scène observée peuvent être à l’origine de problèmes très difficiles à surmonter. Nous présentons différentes méthodes de traitement d’image permettant de prendre en compte au mieux ces conditions de prise de vue instables. Les approches que nous proposons sont définies dans le cadre du modèle LIP (Logarithmic Image Processing). Dans une première partie, nous nous intéressons à des notions de contraste : le contraste LIP additif et un nouveau contraste LIP multiplicatif, ainsi qu’à leurs métriques associées. De nouveaux outils de traitement basés sur ces notions sont ensuite définis : seuillage, détecteur de contours, reconnaissance de modèle. L’utilisation de ces notions de contraste confère à ces algorithmes la capacité des contrastes LIP à s’adapter à différents types d’images mal conditionnées. Nous proposons ensuite de nouvelles techniques de correction de dynamique d’images en exploitant les opérations LIP. Différentes corrections globales et locales sont présentées ainsi que leurs applications directes : correction de dérive d’éclairement pour du contrôle industriel ou amélioration d’image pour de la visualisation. Nous obtenons notamment une méthode de correction locale dont les résultats se rapprochent de ceux de certaines techniques de tone mapping. En comparaison, notre technique s’avère simple, rapide (temps réel à 30 images par seconde) et réaliste car basée sur une interprétation physique de la problématique / The quality of image acquisitions is crucial in the resolution of imaging problems. Troubles during acquisiton can lead to unstability for image processing algorithms. We propose different methods (thresholding techniques, contour detection, pattern matching) based on new metrics and contrasts in the LIP context. The LIP (Logarithmic Image Processing) model is recognized as an efficient framework to process images acquired in transmitted light and to take into account the human visual system. LIP operations are also useful to simulate varitations of image parameters in situation of reflected light. Finally, we propose new methods of global and local dynamic enhancement in the LIP framework like a real time and realistic local dynamic correction that brings results close to those obtained by certain tone mapping methods

En fait, le concept de texture n’est pas facile à définir, mais il est clair qu’il est fortement lié au Système Visuel Humain. Sachant que le Modèle LIP est compatible avec la vision humaine, il nous a semblé intéressant de créer des outils logarithmiques dédiés à l’évaluation de la texture. Nous nous sommes concentrés sur la notion de covariogramme, qui peut être pilotée par diverses métriques logarithmiques. Ces métriques jouent le rôle d’outils de “corrélation”, avec l’avantage de prendre en compte la vision humaine. De plus, les outils LIP sont peu dépendants des conditions d’éclairement et fournissent donc des résultats robustes si celles-ci varient. Les deux derniers Chapitres proposent une nouvelle approche consistant à considérer les niveaux de gris d’une image comme les phases d’un milieu. Chaque phase permet de simuler la percolation d’un liquide dans le milieu, définissant ainsi des trajectoires de percolation. Chaque propagation d’un pixel à un autre est considérée comme facile ou non, en fonction des niveaux de gris traversés. Une « fonction de coût » est créée, qui modifie le « temps » de propagation d’un point à l’autre. De plus, la fonction de coût peut être calculée dans le contexte LIP, pour prendre en compte la vision humaine / This thesis looks at the evaluation of textures in two different perspectives using logarithmic image processing (LIP) framework. The first case after introducing the concept of textures and giving some classical approaches of textures evaluation, it gives an original approach of textures evaluation called covariogram which is derived from similarity metrics like distances or correlations etc. The classical covariogram which is derived from the classical similarity metrics and LIP covariogram are then applied over several images and the efficiency of the LIP one is clearly shown for darkened images. The last two chapters offer a new approach by considering the gray levels of an image as the phases of a medium. Each phase simulates like a percolation of a liquid in a medium defining the percolation trajectories. The propagation from one pixel to another is taken as easy or difficult determined by the difference of the gray level intensities. Finally different parameters like fractality from fractal dimensions, mean histogram etc associated to these trajectories are derived, based on which the primary experiment for the classification of random texture is carried out determining the relevance of this idea. Obviously, our study is only first approach and requires additional workout to obtain a reliable method of classification

The present study is concerned with development of maxilla, or moreprecisely palate,in course of first year of life in patients with unilateral cleft lip and palate (UCLP), before and after cheiloplasty. The metodology has it's center in processing of dental plaster casts of UCLP patients via classical and geometric morphometry. All the patients have been operated following same protocol in the neonatal period. The operation was conducted by the same surgeon Jiří Borský, M.D. in the teaching hospital Motol in Prague. In the trackedThe results suggest that the variability of shape was larger in cUCLP patients than in UCLP+M patients. Statistically significant differences in the palate shape were observed in both age categories within both defect categories. The variability of form (size and shape) was followed within each defect category and statistically significant differences between both age category was proven. In the light of average changes intha palate morphology, we tracked both anterior and posterior growth of both segments with increasing age in both defect categories. More distinctive aproximation of both segments, due to the pressure after the cheiloplasty and growth of both segments, was observed in cUCLP patients. Essencial influence of increasing gravity of the defect on changes...

Doctor Educationis / This study was a cephalometric and dental investigation of the treatment outcomes of UCLP children treated at the Red Cross Children's Hospital (RCCH) with respect to craniofacial morphology and dental arch relationship. The quality of the outcome for the RCCH group was compared with the outcomes reported for the Six-Centre International Study (Melsted et al., 1992; Mars et al., 1992). The sample consisted of 20 (11 females, 9 males) consecutively treated UCLP children who had cephalometric and dental records taken between the ages of8 to 11years (mean 10.13 ± 1.2 years). The cephalometric analysis described by Melsted et al. (1992) was used to evaluate the skeletal and soft tissue morphology. The quality of the dental arch relationship was measured according to the Gosion Yardstick (Mars et al., 1987). The treatment outcome of children treated at the RCCH was evaluated with respect to craniofacial form and dental arch relationship. When comparing the mean cephalometric skeletal parameters of the RCCH to the six centres in the Eurocleft study, a significant difference was found between the RCCH group and centre D for most of the variables. A significant increase in the upper incisor inclination and maxillary inclination was found in the RCCH patients compared to the European centres. The difference in the soft tissue parameters was limited to the relative protrusion of the nose and the sagittal soft tissue variable sss-ns-pgs. The analysis of the Goslon scores showed a significant difference between the RCCH group and centres C, D, and F. According to the Goslon score, 85% of the RCCH patients had good to satisfactory dental arch relationship, which was comparable to that recorded for centres A(92%), B(89%) and C(94). In conclusion, the results of the cephalometric analysis and the Goslon Yardstick showed a significant difference between the RCCH group and centre D. The GosIon score indicated good quality of the dental arch relationship, which faired favourably with the better centres in the Six Centre Study.

No description available.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

published_or_final_version / abstract / Speech and Hearing Sciences / Master / Master of Science in Audiology

A thorough investigation on the existing hydrodynamic lubrication theories and the reverse pumping theories for the conventional lip seal is conducted. On that basis, the algorithms and the methods used in the numerical modeling of the conventional lip seal are modified and applied to the study of the lip seal running against surface textured shafts. For each step of the study, the numerical model is benchmarked against the experimental results. Important physical mechanisms which explain the reverse pumping ability of the triangular surface structures are revealed. Meanwhile, the accuracy of the numerical model is tested. In general, the numerical simulation results match the experimental observation well. However, there are several important discrepancies. For each discrepancy the possible causes are discussed, which benefits the further attempts of the modeling work on the lip seal running against surface textured shafts. The conclusions of this study themselves can be used as a guidance to the design of the surface textured shafts for the lip seal applications. Finally the limitation of the current theories and the modeling methods are discussed and reasonable improvements which can be done are proposed for the future work.

Introducción: La anatomía de la fisura labial bilateral es diferente para cada paciente y varios autores han descrito modificaciones de técnicas tradicionales en la búsqueda de obtener un diseño más individual con mejores resultados. Las técnicas de Millard y Mulliken son probablemente las técnicas quirúrgicas más usadas por los cirujanos alrededor del mundo en el manejo de la fisura labial bilateral, sin embargo existen algunas limitaciones en esta técnica en casos bilaterales con asimetría. En ese sentido, se ha diseñado la presente técnica que busca corregir la asimetría en la fisura bilateral. Esta técnica se basa en un doble avance y rotación lateral localizando las cicatrices sobre las líneas naturales del labio entre las unidades estéticas del mismo. Material y Métodos: Este es un estudio retrospectivo del tipo de serie de casos. Este artículo presenta una nueva técnica para el tratamiento quirúrgico de la fisura labial bilateral usada por el autor en 125 pacientes a manera de estudio retrospectivo descriptivo. Esta técnica está basada en el concepto de doble avance y rotación lateral permitiendo el alargamiento del segmento labial lateral más corto. Estas incisiones son ubicadas sobre las líneas naturales del labio, entre las subunidades estéticas del labio superior, en su mayoría. Se evaluaron los resultados obtenidos con esta técnica considerando el número de malos resultados observados a través del seguimiento de los pacientes en un plazo mayor a un año a través del examen físico directo y el análisis de las fotos postoperatorias estandarizadas. Resultados: Desde 2009 al 2011 esta técnica ha sido usada en 125 fisuras labiales bilaterales. Se obtuvo un buen resultado estético y funcional del labio superior y la nariz con esta técnica. Se observaron 15 / 125 (12 %) de malos resultados. Estas son cirugías que necesitaron revisión secundaria mayor. Conclusiones: Una nueva técnica para el tratamiento de formas asimétricas de fisura labial bilateral se describe aquí. Esta es una técnica que permite alargar el segmento labial lateral más corto de la fisura con buenos resultados estéticos en la reconstrucción del labio superior y nariz de la fisura labial bilateral. / Introduction: The anatomy of bilateral cleft lip is different for each patient, and many authors have described modifications of the traditional repairing techniques in order to achieve more individualized designs and better results. The techniques described by Millard and Mulliken are probably the most commonly used all over the world for repairing bilateral cleft lip; however, there are some short-comings when trying to repair asymmetric forms of bilateral cleft lip. So, we designed this technique aiming to correct asymmetry in bilateral cleft lip. This technique is based on a double advancement and lateral rotation concept placing the scars over the natural lines between the esthetic subunits of the upper lip. Matherial and Methods: This is a retrospective and descriptive study based on a case series. We present a new technique used for surgical repair of bilateral cleft lip in 125 patients. The technique is based in the double advancement and lateral rotation concept which allows lengthening of the shortest lateral lip segment. Most of the incisions are performed on the natural lip landmarks, between the aesthetic subunits of the upper lip. Results were assessed considering the number of failures observed after following up patients for more than one year, performing physical examination and analyzing standardized postoperative pictures. Results: This technique has been used in 125 procedures for repairing cleft lip. We obtained good functional and esthetic outcomes for both nose and lips using this technique. The rate of poor results was 15/125 (12%). These latter procedures had to undergo major secondary surgical revisions. Conclusions: We describe a new technique for surgical repair of asymmetric bilateral cleft lip. This technique led to the elongation of the shortest lateral labial segment, allowing us to achieve good esthetic and functional results on upper lip and nose reconstruction in cases of bilateral asymmetric cleft lip.

Achievement of optimum smile esthetics during orthodontic treatment has recently been the focus of several published articles in the orthodontic literature. Authors speculate that overbite correction, specifically maxillary incisor intrusion, will lead to flattening of the smile arc and consequently reduce smile attractiveness. The purpose of this prospective clinical study was to investigate differences in outcomes from two common treatment modalities used to reduce deep overbite: maxillary incisor intrusion using an intrusion arch and posterior tooth eruption using an anterior bite plate. Pre-treatment and post-overbite correction records were gathered from 20 patients who presented with deep overbite malocclusions to the Virginia Commonwealth University orthodontic clinic. Both the intrusion arch and bite plate treatment modalities effectively reduced overbite significantly over a relatively short period of treatment. Intrusion arch patients displayed significant reductions in maxillary incisor display (lip to tooth) accompanying documented incisor intrusion. Half of the patients in both groups experienced flattening of the smile arc in agreement with previous studies showing similar changes in orthodontic patients in general. There was no greater tendency for flattening to occur in either group. Changes in the smile arc are likely due to other factors involved in orthodontic tooth alignment and are not necessarily attributable to the overbite correction method employed during treatment.