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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Avaliações tegumentares, esqueléticas e dentárias do perfil facial. / Tegumentary, skeletal and dental evaluations of the facial profile.

Klaus Barretto Lopes 04 February 2005 (has links)
O propósito do presente estudo foi avaliar, radiograficamente, a relação entre lábios, pogônio mole, maxila, mandíbula e incisivos em indivíduos com perfil facial equilibrado. Foram avaliados 30 brasileiros do gênero feminino, entre 19 e 31 anos de idade, dos quais foram obtidas telerradiografias em norma lateral, na posição natural da cabeça orientada. A análise cefalométrica foi realizada avaliando-se o nariz, os lábios e o pogônio mole em relação à linha vertical verdadeira que passa pelo ponto subnasal (SnV), a maxila e a mandíbula em relação à base do crânio e os incisivos em relação às suas bases ósseas. Os resultados demonstraram que o lábio superior se apresentou ligeiramente à frente da linha SnV, o lábio inferior se posicionou sobre a linha e o pogônio mole atrás da mesma. Já a maxila se apresentou ligeiramente protruída enquanto que a mandíbula encontrou-se bem posicionada em relação à base do crânio, deste modo, a relação maxílo-mandibular se mostrou um pouco aumentada. Embora os incisivos superiores tenham apresentado inclinações normais, os inferiores se encontraram ligeiramente vestibularizados. Foram, também, observadas correlações positivas estatisticamente significativas entre: o comprimento mandibular e a projeção do lábio inferior; a projeção do pogônio duro e a projeção do pogônio mole; a relação maxilo-mandibular e a relação labial no sentido antero-posterior; a projeção dos lábios e a projeção do pogônio mole. Foi observada, ainda, correlação negativa estatisticamente significativa entre: a inclinação do incisivo inferior e a projeção do lábio inferior; a inclinação do incisivo inferior e a projeção pogônio mole. / The purpose of this study was to radiographically evaluate the relations hip between lips, soft pogonion, maxilla, mandible and incisors in individuals with a balanced facial profile. Thirty Brazilian women aged 19 to 31 years were evaluated, from whom teleradiographs (lateral view) were taken in the natural position of the oriented head. The cephalometric analysis was performed evaluating the nose, the lips and the soft pogonion in relation to the vertical line which passes by the subnasal point (SnV), the maxilla and the mandible in relation to the base of the skull and the incisors in relation to their bone bases. The results demonstrated that the upper lip was slightly forward to SnV line, the lower lip was positioned on the line and the soft pogonion was behind the line. The maxilla was slightly protruded, whereas the mandible waswell positioned in relation to the base of the skull, therefore the maxillomandibular relationship was somewhat augmented. Although the upper incisors had normal inclinations, the lower incisors were slightly protruded. Statistically significant positive correlations were also observed between the mandibular length and the projection of the lower lip; the projection of the hard pogonion and the projection of the soft pogonion; the maxillomandibular relationship and the lip relationship in the anteroposterior direction and between the projection of the lips and the projection of the soft pogonion. A statistically significant negative correlation was also found between the inclination of the lower incisor and the projection of the lower lip and between the inclination of the lower incisor and the projection of the soft pogonion.
12

Hybrid 3D Mass Spring System for Soft Tissue Simulation / Système Masse-Ressort 3D hybride amélioré pour la simulation de tissus mous

Golec, Karolina 19 January 2018 (has links)
La nécessité de simulations de tissus mous, tels que les organes internes, se pose avec le progrès des domaines scientifiques et médicaux. Le but de ma thèse est de développer un nouveau modèle générique, topologique et physique, pour simuler les organes humains. Un tel modèle doit être facile à utiliser, doit pouvoir effectuer des simulations en temps réel avec un niveau de précision permettant l'utilisation à des fins médicales. Cette thèse explore de nouvelles méthodes de simulation et propose des améliorations pour la modélisation de corps déformables. Les méthodes proposées visent à pouvoir effectuer des simulations rapides, robustes et fournissant des résultats physiquement précis. L'intérêt principal de nos solutions réside dans la simulation de tissus mous élastiques a petites et grandes déformations à des fins médicales. Nous montrons que pour les méthodes existantes, la précision pour simuler librement des corps déformables ne va pas de pair avec la performance en temps de calcul. De plus, pour atteindre l'objectif de simulation rapide, de nombreuses approches déplacent certains calculs dans une étape de pré-traitement, ce qui entraîne l'impossibilité d'effectuer des opérations de modification topologiques au cours de la simulation comme la découpe ou le raffinement. Dans cette thèse, le cadre utilisé pour les simulations s'appelle TopoSim. Il est conçu pour simuler des matériaux à l'aide de systèmes masses-ressorts (MSS) avec des paramètres d'entrée spécifiques. En utilisant un MSS, qui est connu pour sa simplicité et sa capacité à effectuer des simulations temps réel, nous présentons plusieurs améliorations basé physiques pour contrôler les fonctionnalités globales du MSS qui jouent un rôle clé dans la simulation de tissus réels. La première partie de ce travail de thèse vise à reproduire une expérience réelle de simulation physique qui a étudié le comportement du tissu porcin à l'aide d'un rhéomètre rotatif. Son objectif était de modéliser un corps viscoélastique non linéaire. A partir de l'ensemble des données acquises, les auteurs de l'expérience ont dérivé une loi de comportement visco-élastique qui a ensuite été utilisée afin de la comparer avec nos résultats de simulation. Nous définissons une formulation des forces viscoélastiques non linéaires inspirée de la loi de comportement physique. La force elle-même introduit une non linéarité dans le système car elle dépend fortement de l'amplitude de l'allongement du ressort et de trois paramètres spécifiques à chaque type de tissu. La seconde partie de la thèse présente notre travail sur les forces de correction de volume permettant de modéliser correctement les changements volumétriques dans un MSS. Ces forces assurent un comportement isotrope des solides élastiques et un comportement correct du volume quel que soit la valeur du coefficient de Poisson utilisé. La méthode nécessite de résoudre deux problèmes: l'instabilité provoquant des plis et les contraintes de Cauchy. Nos solutions à ces limitations impliquent deux étapes. La première consiste à utiliser trois types de ressorts dans un maillage entièrement hexaédrique: les arêtes, les faces diagonales et les diagonales internes. Les raideurs des ressorts dans le système ont été formulées pour obéir aux lois mécaniques de base. La deuxième étape consiste à ajouter des forces de correction linéaires calculées en fonction du changement de volume et des paramètres mécaniques du tissu simulé, à savoir le coefficient de Poisson et le module de Young [etc…] / The need for simulations of soft tissues, like internal organs, arises with the progress of the scientific and medical environments. The goal of my PhD is to develop a novel generic topological and physical model to simulate human organs. Such a model shall be easy to use, perform the simulations in the real time and which accuracy will allow usage for the medical purposes.This thesis explores novel simulation methods and improvement approaches for modeling deformable bodies. The methods aim at fast and robust simulations with physically accurate results. The main interest lies in simulating elastic soft tissues at small and large strains for medical purposes. We show however, that in the existing methods the accuracyto freely simulate deformable bodies and the real-time performance do not go hand in hand. Additionally, to reach the goal of simulating fast, many of the approaches move the necessary calculations to pre-computational part of the simulation, which results in inability to perform topological operations like cutting or refining.The framework used for simulations in this thesis is designed to simulate materials using Mass Spring Systems (MSS) with particular input parameters. Using Mass-Spring System, which is known for its simplicity and ability to perform fast simulations, we present several physically-based improvements to control global features of MSS which play the key role in simulation of real bodies
13

Vliv rehabilitační intervence u poruch měkkých tkání ramenního kloubu u házenkářů / Effect of rehabilitation intervention on soft tissue of shoulder joint at handball players

Honzárková, Aneta January 2020 (has links)
Title: Effect of rehabilitation intervention on soft tissue of shoulder joint in handball players Objectives: The aim of the thesis is to explore the benefits of 10-session conservative therapy in handball players diagnosed with throwing shoulder. The chosen therapy should eliminate the players' difficulties as much as possible and allow them to once again fully engage in the activity. Methods: Experiment-based qualitative research with randomized control study was conducted. The objective was to assess the findings of four probands - players of a major-league team - diagnosed with shoulder joint soft tissue injury caused by playing handball. Two women and two men between the ages of 19 and 30 took part in the research. The subjects were divided into two groups. The first group, a man and a woman, took part in 10 therapeutic sessions, whereas the other did not receive any kind of treatment and served as a reference group. Both initial and final kinesiologic examinations were carried out at the beginning and the end of the therapy, consisting of anamnesis, physical inspection, palpation, anthropometric and goniometric measuring, examination of muscle, muscle shortening, joint movement and movement stereotype. Measured data was analysed and evaluated. Results: After ten successive therapeutic...
14

Možnosti využití indentečních zátěžových zkoušek při studiu mechanických vlastností měkkých tkání pohybového aparátu člověka in vivo, in situ / Possibilities of the use of indentation tests while studying the mechanical properties of soft tissues of the human locomotor system in vivo, in situ

Bittner, Václav January 2020 (has links)
POSSIBILITIES OF THE USE OF INDENTATION TESTS WHILE STUDYING THE MECHANICAL PROPERTIES OF SOFT TISSUES OF THE HUMAN LOCOMOTOR SYSTEM IN VIVO, IN SITU ABSTRACT: The aim of this work was to analyze possibilities of the use of indentation tests, while studying mechanical properties of human locomotor system soft tissues in vivo, in situ. The synthesis of published findings and the results of our own surveys were used. A mathematical model of the indentation test was created as a part of theory. The geometry of the task was formulated as a solid cylinder penetrating into an infinite half-space made of viscoelastic material. The solution is based on the traditional analytical approach concerning stationary loading of flexible material. This procedure is generalized for Neo-Hooke's hyperelastic material and large deformations. The quantification of dissipative processes is based on the assumption that the stress tensor of a viscoelastic material can be decomposed into a purely elastic constituent and a purely dissipative constituent. The model enables to determine both elastic and viscous properties of the material. Experimental part of the work includes validation experiments. Based on the findings, it can be stated that myotonometry is a valid diagnostic method that allows an objective assessment of muscle tone...
15

Korelace imunohistochemických a molekulárně biologických metod v diagnostice nádorů / Correlation of Immunohistochemistry and Molecular Biologic Methods in The Diagnosis of Tumors

Michal, Michael January 2018 (has links)
This thesis is a collection of commentaries on altogether 13 first-authored and 20 co- authored publications where morphology, immunohistochemistry (IHC) and molecular genetic methods were used to provide novel clues for arriving at an accurate diagnosis of tumors, as well as to propose novel approaches and refinement of classification of certain tumors. The presented manuscripts are the result of the postgraduate studies of MUDr. Michael Michal at the Charles University in Prague, Faculty of Medicine in Pilsen in the period between 2015-2018. The author focused the main part of his research, particularly his first-authored manuscripts, on soft tissue tumors but also largely participated in research activities focusing on other body systems. Over the course of his studies, four main areas of interests within the topic of soft tissue pathology emerged. The first is oriented on soft tissue tumors of presumed (but unconfirmed) fibroblastic lineage. First two publications regard two related low-grade sarcomas called Myxoinflammatory fibroblastic sarcoma (MIFS) and Pleomorphic hyalinizing angiectatic tumor (PHAT). In the first manuscript, a high-grade variant of the former is described. The latter publication is focused on the morphological and IHC similarities between both MIFS and PHAT. The third and...
16

A Finite Element Model for Mixed Porohyperelasticity with Transport, Swelling, and Growth

Armstrong, Michelle Hine, Buganza Tepole, Adrián, Kuhl, Ellen, Simon, Bruce R., Vande Geest, Jonathan P. 14 April 2016 (has links)
The purpose of this manuscript is to establish a unified theory of porohyperelasticity with transport and growth and to demonstrate the capability of this theory using a finite element model developed in MATLAB. We combine the theories of volumetric growth and mixed porohyperelasticity with transport and swelling (MPHETS) to derive a new method that models growth of biological soft tissues. The conservation equations and constitutive equations are developed for both solid-only growth and solid/fluid growth. An axisymmetric finite element framework is introduced for the new theory of growing MPHETS (GMPHETS). To illustrate the capabilities of this model, several example finite element test problems are considered using model geometry and material parameters based on experimental data from a porcine coronary artery. Multiple growth laws are considered, including time-driven, concentrationdriven, and stress-driven growth. Time-driven growth is compared against an exact analytical solution to validate the model. For concentration-dependent growth, changing the diffusivity (representing a change in drug) fundamentally changes growth behavior. We further demonstrate that for stress-dependent, solid-only growth of an artery, growth of an MPHETS model results in a more uniform hoop stress than growth in a hyperelastic model for the same amount of growth time using the same growth law. This may have implications in the context of developing residual stresses in soft tissues under intraluminal pressure. To our knowledge, this manuscript provides the first full description of an MPHETS model with growth. The developed computational framework can be used in concert with novel in-vitro and in-vivo experimental approaches to identify the governing growth laws for various soft tissues.
17

Etude biomécanique de l’action des Bas Médicaux de Compression sur les parois veineuses du membre inférieur / Biomechanical response of lower leg veins to Medical Elastic Compression

Rohan, Christian Pierre-Yves 03 December 2013 (has links)
La compression élastique est la thérapeutique conservatrice la plus efficace pour la prise en charge de l'insuffisance veineuse et pour le traitement de la maladie veineuse chronique et de ses complications. Malheureusement, en pratique, les objectifs thérapeutiques ne sont pas toujours atteints ce qui souligne le manque de connaissance actuel concernant les mécanismes qui permettent aux Bas Médicaux de Compression (BMC) d'apporter les bienfaits thérapeutiques. Pour apporter des éléments de réponse, une étude numérique de l’action des BMC sur les veines a été réalisée. Dans un premier temps, une nouvelle méthodologie a été développée pour prévoir les pressions transmises aux parois des veines superficielles et pour quantifier la diminution de la pression transmurale et du calibre que la compression engendre. Une étude de sensibilité réalisée à partir du modèle Eléments Finis développé a permis de mettre en évidence les principaux paramètres qui conditionnent l’action des BMC. Il a ensuite été utilisé pour simuler différents scénarios d’application en lien avec la compression en post-sclérothérapie pour répondre à des problématiques industrielles. Dans une deuxième phase de l’étude, une méthode de modélisation numérique de la réponse des veines profondes à la contraction musculaire lors du port d’un BMC a été développée. Une étude de sensibilité a permis d’apporter des éléments de réponse quant à l’influence relative des aponévroses musculaires, de la contraction musculaire et du port d’un BMC. Ces travaux ouvrent des perspectives d’études nouvelles sur le développement d’outils pour permettre aux fabricants de BMC d’adapter le niveau de compression à chaque patient. / Compression therapy is a highly effective modality for treating venous disorders of the lower leg and is considered as the “gold standard” for non-operative therapy. However the mechanisms by which Medical Compression Stockings (MCS) benefit the control and treatment of venous insufficiency are neither clearly understood nor have they been conclusively demonstrated. In the present study, the biomechanical response of the lower leg veins to elastic compression is modelled in order to address some of the issues relating to the mechanisms by which it achieves its medical function. First, a new methodology has been developed in order to predict the pressure transmitted to the superficial vein wall during external compression and to quantify the resulting variations of transmural pressure and of the vein cross sectional area. A parametric study was performed to study the influence of the model parameters on the response of the vein. The developed model was also used to simulate different scenarii related to the use of elastic compression after sclerotherapy. In a second step, a numerical approach was developed to model the biomechanical response of deep veins to elastic compression. A parametric study was performed to evaluate the relative influence of the muscular aponeurosis, muscular contraction and external compression applied by MCS. The obtained results bring a new insight on MCS mechanical action and its possible benefits. They also open up new perspectives, especially, regarding the development of new tools to assist MCS manufacturers in adapting the level of compression to the location of the deep vein, the morphology of the patient and the severity of the disease.
18

Optimisation d’une manchette élastomère silicone pour sphincter artificiel urinaire mécatronique. / Optimization of an elastomeric silicone cuff for an artificial mecatronic urinary sphincter

Masri, Christopher 16 October 2017 (has links)
La société UroMems propose de résoudre les problèmes d’incontinence urinaire avec un nouveau sphincter urinaire artificiel, dans lequel le mécanisme de pompe manuelle utilisé dans les sphincters actuellement implantés dans de nombreux patients est remplacé par un dispositif mécatronique. Une manchette occlusive, mimant le fonctionnement du sphincter naturel, est reliée et activée par le dispositif afin d’autoriser la miction et l’incontinence du patient.Le travail de thèse s’oriente sur la compréhension et l’amélioration du sphincter artificiel. La première partie de cette étude porte sur la numérisation et la modélisation 3D de cette manchette, la caractérisation mécanique de ses différents composants et la mise en place d’un modèle éléments finis. Un banc de test sur un cas simple avec suivi par stéréo-corrélation d’images est également présenté afin de valider le comportement du modèle numérique pour un chargement simple. La deuxième partie porte sur la simulation du geste chirurgical et du fonctionnement de la manchette ainsi qu’une validation du modèle éléments finis en comparaison avec des mesures effectuées sur paillasse. La troisième partie de ce travail consiste à produire des données expérimentales sur sujet anatomique afin d’observer le fonctionnement de la manchette dans son environnement naturel. Les résultats de cette étude ont motivé l’utilisation d’un matériau fantôme (un hydrogel de Polyvinyl alcohol) dont les propriétés mécaniques sont ajustables. Une caractérisation mécanique de cet hydrogel est présentée ainsi qu’un banc d’essai servant de cas test pour la validation du modèle numérique complet. La quatrième partie propose une analyse histo-morphologique de l’urètre masculin, ainsi qu’une caractérisation mécanique complète. Les données obtenues sont ensuite intégrées au modèle éléments finis afin de simuler le fonctionnement de la manchette occlusive dans son environnement naturel. Dans la dernière partie l’outil numérique mis en place est exploité afin de proposer des pistes d’améliorations du sphincter artificiel actuel. / UroMems aims at developing a novel treatment solution for severe urinary incontinence by replacing the manual pump mechanism, which is currently considered as the gold standard and which is implanted in patients throughout the world, by a mechatronic device. An occlusive cuff that mimics the natural human sphincter is linked to the device in order to ensure continence and allow micturition.This work focuses on understanding and improving the artificial sphincter. The first part of this study aims at modeling of the occlusive cuff, characterizing the mechanical behavior of all of its components and establishing a corresponding finite element model. A bench test using digital image correlation is also presented in order to validate the behavior of the numerical model for a simple test. In the second part the implantation of the occlusive and its inflation are simulated and the model is validated by comparing its results to the data measured experimentally. The third part aims at validating the interaction between the occlusive cuff and an extraneous body in the numerical simulation. To this end the in vivo experimental behavior of the occlusive cuff is observed. The variability measured among the different subjects motivated the use of a phantom material (a Polyvinyl alcohol hydrogel) of controlled mechanical properties. A thorough mechanical characterization of the hydrogel is also presented in this part as well as a test bench used for the validation of the numerical model. The fourth part proposes a histo-morphological analysis of the male urethra and its mechanical characterization. The data obtained were then integrated to the finite element model. The last part of this work is dedicated to exploiting the finite element tool to propose design improvement of the occlusive cuff.
19

Contribution mécanique à la réduction des marges en radiothérapie de la prostate : modélisation et simulation numérique du mouvement et de la déformation des organes pelviens / Mechanical approach for reducing margins during prostate radiotherapy : modeling and finite element simulation of the motion and deformation of pelvic organs

Boubaker, Mohamed Bader 03 December 2009 (has links)
La prostate est un organe pelvien qui joue un rôle important dans son environnement anatomique, notamment en assurant la sécrétion d’un liquide essentiel dans la composition du liquide séminal. Le cancer de la prostate représente la première cause mortalité chez l’homme à un âge avancé. Ce travail concerne le développement par la méthode des éléments finis d'un modèle numérique du mouvement des organes pelviens (prostate, vessie, rectum) et de leurs interactions. L’objectif est la réduction des marges d'irradiation du volume cible au cours d'une séance de radiothérapie, afin de ne pas altérer les organes sains avoisinants. Les marges choisies sont importantes compte tenu du fait que la prostate subi des déplacements importants lors des interactions permanentes avec les organes avoisinants. Un premier modèle est construit à partir de la géométrie des organes pelviens générée à partir d'images scanner acquises sur patients. Des lois hyper-élastiques sont adoptées pour modéliser le comportement mécanique du rectum et de la vessie et un comportement Hookéen est considéré pour la prostate. Les paramètres physiques du modèle sont déterminés à partir de la littérature, des données expérimentales et de nos propres mesures. Les conditions aux limites cinématiques et statiques (pressions de distension intra-vésicale et intra-rectale) sont définies à partir des observations anatomiques et reflètent la présence de l’entourage anatomique et les conditions de chargement. Des comparaisons entre les variations de forme et de position d'organes obtenues par simulation et les mesures obtenues par imagerie scanner (Keros et al. ; 2006) montrent des amplitudes de déplacements proches, avec des écarts variant entre 8% et 11%. Un modèle prenant en compte la variabilité des paramètres physiques inter et intra patients est envisagé en perspectives / The prostate plays an important biological role in the human body, such as secretion of some prostatic liquid essential in the semen composition. Prostate cancer is the first cause of mortality for men at an advanced age. The prostate motion due to the interactions with the surrounding anatomic entities is difficult to predict, hence important margins are usually adopted during X-ray irradiation, in order not to damage the surrounding healthy organs (bladder and rectum). The principal objective of this work is to set up a FE model of the motion and deformation of the human pelvic organs in order to reduce the margins. A first model is constructed from CT-scans of the human pelvic organs, allowing the generation of the organ geometrics. Hyperelastic modeling of the bladder and rectum behaviors were considered whereas a Hookean model was retained for the prostate. The model parameters are fixed by adopting literature data, experimental data (from CHU-Nancy) and experimental measurements achieved on pig. Boundary conditions are defined according either surrounding anatomy kinematic constraints or internal pressures that correspond to the bladder and rectum repletion’s. Simulated displacements show order of magnitudes of the prostate motion very close to measurements carried out by Keros et al. (2006) on a deceased person, with a relative error ranging from 8% to 11%. Those differences are essentially due to the variability in the physical parameters, pointing out the need for a statistical approach in order to take into account the material, geometrical and loading variability related to a panel of patients
20

Influência do afastamento labial na avaliação tomográfica dos tecidos ósseo e gengival da maxila anterior

Silva, Jesca Neftali Nogueira 27 April 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-09T16:37:05Z No. of bitstreams: 1 jescaneftalinogueirasilva.pdf: 1568191 bytes, checksum: f265e2e8c149f785a2db409c3d85c37c (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2015-12-10T13:58:43Z (GMT) No. of bitstreams: 1 jescaneftalinogueirasilva.pdf: 1568191 bytes, checksum: f265e2e8c149f785a2db409c3d85c37c (MD5) / Made available in DSpace on 2015-12-10T13:58:44Z (GMT). No. of bitstreams: 1 jescaneftalinogueirasilva.pdf: 1568191 bytes, checksum: f265e2e8c149f785a2db409c3d85c37c (MD5) Previous issue date: 2015-04-27 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O objetivo no presente estudo foi avaliar a espessura da tábua óssea vestibular e do tecido gengival na região de incisivos superiores, em imagens de tomografia computadorizada de feixe cônico (TCFC), obtidas com e sem afastador labial. Tratase de um estudo clínico-tomográfico em que foram coletados dados da espessura da tábua óssea e gengiva vestibular de 120 incisivos superiores. Em exames de TCFC, obtidos com e sem afastador labial, foram realizadas medidas de espessuras óssea e gengival em diferentes regiões. Para validar a utilização da TCFC na mensuração do tecido gengival, medidas tomográficas foram correlacionadas com as medidas obtidas por sondagem clínica. As imagens com e sem afastador foram ainda comparadas em relação a sua qualidade. A medida de espessura óssea localizada na porção mais cervical (1 mm acima da crista óssea) apresentou uma média superior para os exames realizados com afastador labial (teste t pareado/ p = 0,021). As medidas de espessura da tábua óssea apresentaram correlações significativas com as espessuras do tecido gengival (correlação de Pearson/ p ≤ 0,02). O tecido gengival pode ser mensurado apenas em exames de TCFC obtidos com afastador labial, e as espessuras gengivais obtidas em TCFC apresentaram correlações significativas com aquelas obtidas clinicamente (correlação de Pearson/ p ≤ 0,001). Em relação à preferência dos avaliadores, 76% dos radiologistas e 56% dos implantodontistas preferiram as imagens obtidas com o afastador. Concluiu-se que a utilização de afastadores labiais durante a obtenção de exames de TCFC é uma técnica simples e confiável, que permitiu, além da avaliação do tecido ósseo, a mensuração dos tecidos gengivais. / The aim of this study was to evaluate the thickness of the buccal bone and the gingival tissue in the region of upper incisors by using computed tomography cone beam (CBCT), obtained with or without lip retractor. This is a clinical-tomographic study, in which the thickness of the buccal bone and gingiva were collected from 120 upper incisors. Bone and gingival thickness, with and without lip retractor, were measured in different regions of CBCT images. To validate the use of CBCT for measuring gingival tissue, the tomographic measurements were correlated with data acquired by clinical probing. The images with or without lip retractor were also compared regarding their quality. The bone thickness measurement located at the cervical portion (1 mm above the bone crest), was higher when lip retractor was employed (paired t-test/ p = 0.021). The thicknesses of the bone tissue were significantly correlated with those of the gingival tissue (Pearson correlation/ p ≤ 0.02). The gingival tissue could only be measured in CBCT scans obtained with lip retractor. The gingival thickness from CBCT showed significant correlations with those obtained clinically (Pearson correlation/ p ≤ 0.001). Regarding the preference of the evaluators, 76% of radiologists and 56% of implant specialists preferred the images obtained with the lip retractor. It was concluded that in addition to the classical bone tissue examination, the use CBCT with lip retractor is a simple and reliable technique for measuring the gingival tissues.

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