Дисертації з теми "Orthodontic applications"
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1
Moylan, Heather. "Accuracy of a smartphone-based orthodontic treatment monitoring application." VCU Scholars Compass, 2018. https://scholarscompass.vcu.edu/etd/5393.
Анотація:
Objectives: Dental Monitoring® (“DM,” Dental Monitoring, Paris, France), is a cloud-based software that allows orthodontists to track patients’ treatment remotely. The purpose of this study was to investigate the accuracy of the software in making linear measurements.
Methods: Patients took intraoral photographs using the DM application, immediately followed by impressions for plaster models. Intercanine and intermolar width and arch depth measurements were made by DM and compared to measurements made on the plaster models. Data was analyzed using two one-sided t-tests for equivalence with equivalence bounds of
+/-0.5mm. Significance level was set at 0.05.
Results: Thirty sets of measurements were compared. The intercanine and intermolar measurement differences were on average 0.17mm and -0.02mm, respectively, and were deemed equivalent. The arch depth measurements had an average difference of -0.54mm and were deemed not equivalent.
Conclusion: The monitoring software seems to provide an accurate assessment of linear tooth movements.
2
Doan, Tien Tai. "Réalisation d’une aide au diagnostic en orthodontie par apprentissage profond." Electronic Thesis or Diss., université Paris-Saclay, 2021. http://www.theses.fr/2021UPASG033.
Анотація:
L'analyse et le diagnostic précis à partir d'images dentaires sont un facteur essentiel de la réussite des traitements orthodontiques. De nombreux procédés de traitement d'image ont été proposés pour résoudre ce problème. Cependant, ces études fonctionnent principalement sur de petits ensembles de données de radiographies dans des conditions de laboratoire et ne sont pas vraiment applicables en tant que produits ou services complets. Dans cette thèse, nous construisons des modèles d'apprentissage profond pour diagnostiquer des problèmes dentaires tels que la gingivite et les dents chevauchées à l'aide de photos prises par de téléphones portables. Nous étudions les couches cachées de ces modèles pour trouver les forces et les limites de chaque méthode. Nous proposons un pipeline complet intégrant le prétraitement des images, l'apprentissage du modèle et le post-traitement des résultats pour créer un processus d'analyse complet prêt à être mis en production en situation réel. Afin d'améliorer la fiabilité des modèles, nous avons étudié différentes méthodes d'augmentation des données, en particulier les méthodes d'adaptation de domaine en utilisant des approche de transfert d'images, à la fois supervisée et non supervisée, et obtenons des résultats prometteurs. Les approches de transformation d'images sont également utilisés pour simplifier le choix des appareils orthodontiques par les patients en leur montrant à quoi pourraient ressembler leurs dents pendant le traitement. Nos méthodes permettent de générées des images réalistes et en haute définition. Nous proposons également un nouveau modèle de transformation d'image non supervisé qui peut manipuler les caractéristiques de l'image sans nécessiter d'annotation supplémentaire. Notre modèle surpasse les techniques de pointe sur plusieurs applications de transformation d'images et est également étendu pour les problèmes de « few-shot learning »Accurate processing and diagnosis of dental images is an essential factor determining the success of orthodontic treatment. Many image processing methods have been proposed to address this problem. Those studies mainly work on small datasets of radiographs under laboratory conditions and are not highly applicable as complete products or services. In this thesis, we train deep learning models to diagnose dental problems such as gingivitis and crowded teeth using mobile phones' images. We study feature layers of these models to find the strengths and limitations of each method. Besides training deep learning models, we also embed each of them in a pipeline, including preprocessing and post-processing steps, to create a complete product. For the lack of training data problem, we studied a variety of methods for data augmentation, especially domain adaptation methods using image-to-image translation models, both supervised and unsupervised, and obtain promising results. Image translation networks are also used to simplifying patients' choice of orthodontic appliances by showing them how their teeth could look like during treatment. Generated images have are realistic and in high resolution. Researching further into unsupervised image translation neural networks, we propose an unsupervised imageto- image translation model which can manipulate features of objects in the image without requiring additional annotation. Our model outperforms state-of-the-art techniques on multiple image translation applications and is also extended for few-shot learning problems
3
Ali, Khaled Abedela Mahdi. "Application of zirconium-coated titanium wires as restorative orthodontic materials." Thesis, Cape Peninsula University of Technology, 2013. http://hdl.handle.net/20.500.11838/1532.
Анотація:
Thesis submitted in fulfillment of the requirements for the degree
Magister of Technology: Dental Technology
In the Faculty of Health & Wellness Sciences
At the Cape Peninsula University of Technology
2013Orthodontic archwires are made from different alloys. It is now possible to match phases of treatment with orthodontic archwires according to its mechanical properties. On this basis, the titanium molybdenum alloys (TMA) in its beta phase have an excellent combination of strength and flexibility when used as archwires to apply biomechanical forces that affect tooth movement. It has recently gained increased popularity in orthodontic treatment. There are, however, disadvantages associated with the use of orthodontic archwires, such as high surface roughness, which increases friction at the archwire-brackets interface during the sliding process. The surface roughness of dental materials is of utmost importance. Properties such as desirable tensile strengths, load deflection, hardness and low modulus of elasticity and resistance against corrosion & wear determine the area of the contact surface, thereby influencing the friction. The main object of this study was to improve the strength and surface roughness of the beta-titanium orthodontic archwires (β-Ti III) and timolium archwires (TIM), taking into account of retention of the archwires strength. The following tasks were performed. Layers of Zr were deposited on the β-Ti archwires and compared with the archwire strength before and after Zr deposition. The structure of selected archwires and its composition and surface roughness was investigated before and after Zr deposition, using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The force of selected archwires before and after deposition with layers of Zr by Hounsfield deflection testing was studied. Two commercially available orthodontic archwires were used in this study, namely, β-Ti III and TIM orthodontic archwires. The archwires were cut into 25 mm long specimens. In this study, the electron beam-physical vapour deposition (EB-PVD) technique was applied to deposit pure Zr (thicknesses of 5, 10, 25 and 50 nm) on selected archwires and the effects thereof were investigated using AFM, SEM and the Hounsfield deflection test. Results of SEM and AFM analysis and deflection tests showed significant differences between Zr-coated archwires compared with uncoated archwires. Zr-coated archwires (5, 10, 25 and 50 nm depositions) had reduced surface roughness compared with uncoated archwires. A high load deflection rate was exhibited by the coated β-Ti III archwires and a low load deflection rate was exhibited by the coated TIM archwires. There was a difference in load deflection rate between the coated and uncoated archwires. Deposition of 5, 10, 25 and 50 nm Zr on both types of β-Ti orthodontic archwires is recommended for even sliding mechanics due to resulting reduced surface roughness with a good load deflection rate compared with uncoated β-Ti orthodontic archwires. KEYWORDS Surface roughness Zirconium Titanium Deflection test Beta titanium orthodontic archwires Orthodontic archwires alloys Coated materials Electron beam-physical vapour deposition Scanning electron microscopy Atomic force microscopy
4
Ulff, Nicolas. "Analyse et prise en compte des effets de l’hydrogène sur le comportement thermomécanique des AMF à base NiTi." Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0308.
Анотація:
Les progrès des nombreux champs qui composent la médecine possèdent de nombreuses origines, l'une d'entre elles étant l'évolution des matériaux utilisés. En particulier, l'essor des matériaux dit intelligents permet d'envisager de nouvelles solutions techniques, ou bien d'améliorer significativement les dispositifs existants ou leur tenue en service. Les alliages à mémoire de forme font partie de cette famille des matériaux intelligents, en raison de leur comportement dépendant de la température. Leur comportement mécanique est par conséquent plus complexe par rapport à des matériaux plus connus comme les aciers. Cela permet par exemple d'atteindre un niveau de déformation réversible de l'ordre de plusieurs pourcents. L'une des premières applications de ces matériaux concerne le domaine de l'orthodontie, avec le développement de fil orthodontique en alliage à mémoire de forme NiTi. Son intérêt est de profiter de l'application d'une force quasi-constante au cours du traitement. Une problématique à laquelle sont confrontés les chirurgiens-dentistes est celle due à la présence d'hydrogène qui conduit à une rupture prématurée et d’une dégradation des propriétés mécaniques de fils en NiTi lors des traitements orthodontiques. Le caractère fragile de la rupture est un indice sur l'origine multi-physique de ce problème. Ce sujet de thèse propose d'analyser ces effets de l'hydrogène sur le comportement pour ensuite prendre en compte les phénomènes prépondérants dans un modèle élément fini. Pour cela, on s'appuiera sur des résultats expérimentaux pour développer un modèle de comportement couplé chimio-thermo-mécanique adapté. Deux éléments finis (2D et 3D) à degrés de liberté chimio-thermo-mécanique seront formulés en considérant la loi de comportement développée. Ils seront ensuite implémentés dans Abaqus via une UEL pour étudier les effets de la diffusion de l'hydrogène et son absorption sur le comportement ainsi que ses répercussions, par exemple sur le piégeage de martensite. Les prédictions par éléments finis des effets de l'hydrogène sur les performances des arches dentaires en AMF NiTi seront confrontées aux observations expérimentalesAdvances in the many fields that form medicine have many origins, one of them being the evolution of the materials used. In particular, the rise of the intelligent materials enables to consider new technical solutions, or to significantly improve existing devices. Shape memory alloys belong to this family of intelligent materials, due to their temperature dependent behavior. Their mechanical behavior is therefore more complex compared to more well-known materials such as steels. This allows, for example, to achieve a level of reversible deformation of the order of several percent. One of the first applications of these materials concerns the field of orthodontics, with the development of orthodontic wire in NiTi shape memory alloy. Its interest is to take advantage of the application of an almost constant force during the treatment. One problem with which dentists are confronted is due to the presence of hydrogen which leads to premature rupture and degradation of NiTi wires mechanical properties during orthodontic treatments. The brittle nature of the rupture is an indication of the multi-physical origin of this issue. This PhD proposal will focus on the analysis of these hydrogen effects on the thermomechanical behavior of Shape Memory Alloys (SMAs) in order to develop a finite element model. For that end, experimental characterizations will be carried out and analysis of obtained results will allow to formulate an adapted coupled chemo-thermo-mechanical constitutive model. This behavior model will be integrated in two special finite elements (2D and 3D) with coupled degrees of freedom (thermal, mechanical and chemical degrees of freedom). These elements will be implemented in the Abaqus code via the subroutine UEL. The obtained numerical tool will allow to analyze the effect of hydrogen diffusion on the performance of SMA-based orthodontic arches. These finite element predictions will be confronted with experimental observations
5
Willson, Timarah Grace. "The angiogenic response of human dental pulp to orthodontic force application." Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/the-angiogenic-response-of-human-dental-pulp-to-orthodontic-force-application(518decf5-ed49-4c36-b2a0-99a56f089802).html.
Анотація:
In order to characterise the angiogenic response of human dental pulps to orthodontic force application, transcriptomic and proteomic changes were investigated relative to three early time-points of routine clinical treatment in contralateral pairs of treated and control teeth. It was hypothesised that varied intensities of hypoxic exposure (intermittent, repeated intermittent and chronic) would result in distinct angiogenic responses within untreated pulp tissues. It was further hypothesised that angiogenic responses of pulps exposed to early time-points of orthodontic treatment would correlate with those of tissues exposed to varied hypoxic intensities; and changes would be associated with known stages of clinical treatment, namely: initial, lag, acceleration and linear phases of orthodontic tooth movement. Prior to performing all experimentation, methodologies for handling of rare clinical samples were established. Protocols for sample storage, homogenisation, RNAtotal isolation, quantification, purification and amplification were optimised; a normalising factor created from the mean expression of reference genes RPL13A and UBC was found to be most appropriate for RT-qPCR analysis of human dental pulps under these experimental conditions. Orthodontic force application resulted in a potential angiogenic or putative inflammatory response at all treatment time-points; and altered gene expression associated with hypoxia is evident in pulps following 2 weeks of force application. The response to each defined hypoxic intensity was unique; and the associated angiogenic response correlated with the duration of hypoxic exposure. Reoxygenation following hypoxia was linked to the putative inflammatory response of pulps during orthodontic treatment. Results showed that the experimental potential of a single clinical sample can be amplified significantly, dependent upon the selection of specific experimental protocols; thus eliminating the need for pooling samples or using cell lines which are far removed from true physiological conditions. Both angiogenesis and hypoxia appear to have a significant role in response of human dental pulps to routine orthodontic treatment.
6
Maumela, Patricia Mutsinda. "Application of the dental aesthetic index in the prioritization of orthodontic service needs." Thesis, University of Limpopo (Medunsa Campus), 2010. http://hdl.handle.net/10386/444.
Анотація:
Thesis (M.Med. (Orthodontics))--University of Limpopo, 2010Introduction: Orthodontic services in South Africa are mainly offered by the private sector and to a lesser extent by the four government funded training institutions which are plagued by limited resources. The majority of patients cannot afford private fees and seek treatment at these training institutions. The growing number of patients on waiting lists is a problem. Prioritization of orthodontic services would assist to ensure that these services are preferentially provided to those patients most likely to derive the greatest benefit. The Dental Aesthetic Index (DAI) is used to estimate orthodontic treatment need and can also be used as a screening tool to determine treatment priority (Cons, Jenny & Kohout, 1986). The DAI focuses on aesthetics and therefore omits other malocclusion traits thereby limiting its comprehensiveness as an assessment tool. To date no published study has been found that identified other malocclusion traits not included in the DAI and examined the influence that these malocclusion traits have in the prioritization of orthodontic service needs whilst using the DAI. Thus the aim of this research was to assess the application of the DAI to prioritize orthodontic services needs within a government funded institution. The objectives were: 1) To identify other malocclusion traits not included in the DAI. 2) To evaluate how much influence other malocclusion traits not included in DAI have in the prioritization of orthodontic service needs. 3) To compare the mean DAI scores according to age and gender. Materials and methods: One hundred and twenty (120) pre-treatment study models of patients in the permanent dentition stage were collected from the records archive of the Department of Orthodontics, University of Limpopo (Medunsa campus) using a systematic sampling method. The study models were assessed using the DAI by two calibrated examiners. Other malocclusion traits were identified and recorded according to the basic method for recording occlusal traits (Bezroukov et al., 1979). Specific codes were assigned to each identified malocclusion trait from code 01 to 09. The traits were recorded once, by marking the respective code/malocclusion trait with an x when present on each study model. Descriptive statistics, Pearson correlation coefficient, Chi-square values and t-tests were employed to analyze the data and p values of less than or equal to 0.05 (p < 0.05) were considered statistical significant. Results: The sample consisted of 58 females and 62 males, aged 10-45 years with a mean age of 17.9 years and a SD of 6.2 years. The DAI scores showed that 19.1% had normal or minor malocclusion, 17.5% had definitive malocclusion, 21.7% had severe malocclusion and 41.7% had handicapping malocclusion. The mean DAI score was 35.2 with a SD of 10.3. A statistical significant difference was found between mean DAI score of adults and adolescence (p < 0.05), while no statistical significant difference was found between males and females (p > 0.05). The study identified the following other malocclusion traits: crowded and rotated posterior teeth (27.5%), posterior crossbite (22.8%), retained primary teeth (13.4%), missing molars (10.7%), partially erupted teeth (9.4%), deep overbite (8.1%), transposition (3.4%), peg lateral (3.4%) and supernumerary teeth (1.3%). These malocclusion traits accounted for 21.1% of the total malocclusion traits of the sample whilst the DAI accounted for 78.9%. About 47.6% of these other malocclusion traits were found in handicapping category of the DAI, 19.5% in the severe category, 18.1% in the definitive category and 14.8% in the normal or minor category. The distribution of subjects over the four DAI categories and the distribution of subjects with other malocclusion traits over the same DAI categories did not differ significantly (Chi-square test, p = 0.917). The intra and inter examiner reliability was tested using the Pearson correlation coefficient and found to be highly correlated (r = 0.9). Conclusions: The study showed that the DAI is a valid and reliable index that can be applied to prioritize orthodontic service needs in a financially constrained situations without any modification as two thirds of other malocclusion traits were found in categories which the DAI had already prioritized for treatment.
7
Bednar, Eric David Proffit William R. "Application of distance learning to interactive seminar instruction in orthodontic residency programs." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2007. http://dc.lib.unc.edu/u?/etd,941.
Анотація:
Thesis (M.S.)--University of North Carolina at Chapel Hill, 2007.Title from electronic title page (viewed Dec. 18, 2007). "... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Orthodontics of the School of Dentistry." Discipline: Orthodontics; Department/School: Dentistry.
8
Srivicharnkul, Pennapa. "Changes In Physical Properties Of Human Premolar Cementum After The Application Of Controlled Orthodontic Forces." Thesis, Faculty of Dentistry, 2009. http://hdl.handle.net/2123/4406.
9
AUDIN-OLIVAUX, AUDIN PASCALE. "Contribution a la modelisation des contours deformables : application a l'analyse de cephalogrammes en orthodontie." Besançon, 1995. http://www.theses.fr/1995BESA2007.
Анотація:
Les travaux presentes dans ce memoire de these concernent la definition d'un ensemble de modeles coherents, pour l'identification semi-automatique des points cephalometriques figurant sur des radiographies du profil de la face, en orthodontie. Le systeme de reconnaissance de formes que nous proposons est base sur l'utilisation d'un modele de contours deformables associes aux contours recherches. L'elaboration de ce systeme nous conduit tout d'abord a definir un modele de prelocalisation des contours deformables et d'estimation de la position des points a identifier, en fonction de l'enrichissement du modele au fur et a mesure de la detection des points. Cette recherche est basee sur un maillage aux elements finis, constitue d'elements barre. Lors de la phase de pretraitement d'une radiographie, la forme du maillage est adaptee au profil cranien etudie, a partir des conditions limites portant sur trois points, et d'un modele d'adaptation de formes. Les modeles de contours deformables, judicieusement lies au maillage, sont prepositionnes sur l'image en mode solide puis se deforment sous l'action d'efforts exerces par les gradients des niveaux de gris de l'image. Les deformations du contour sont operees en exploitant la theorie des poutres en resistance des materiaux, a partir de l'equation differentielle de la deformation de la ligne moyenne d'une poutre soumise a un torseur d'efforts
10
Aljehani, Abdulaziz Saad. "Application of two fluorescence methods for detection and quantification of smooth surface carious lesions /." Stockholm, 2006. http://diss.kib.ki.se/2006/91-7140-793-6/.
11
Chutimanutskul, Wanjira. "Changes In Physical Properties Of Human Premolar Cementum After Application Of Four Weeks Of Controlled Orthodontic Forces." Thesis, Faculty of Dentistry, 2004. http://hdl.handle.net/2123/4405.
12
Sampeur, Maud. "Validation de la tomodensitométrie dans l'exploration quantitative des muscles masticateurs : mise en application en orthodontie." Toulouse 3, 2008. http://thesesups.ups-tlse.fr/1212/.
Анотація:
La tomodensitométrie a fait son apparition en Orthodontie dans les années 2000 couplé avec des analyses en trois dimensions céphalométriques. La recherche a mis en évidence l'impact des muscles masticateurs sur le développement et le fonctionnement des structures osseux. Or avant l'apparition du scanner, les seuls moyens d'exploration reposaient sur l'electromyographie et l'ultrasonographie. Ayant pour finalité la mise au point d'une analyse musculaire couplée à la céphalométrie sur les examens scanners, nous avons pour objectif de prouver la fiabilité de la tomodensitométrie dans l'analyse quantitative des muscles masticateurs (masséters, ptérygoïdien médial et latéral). Nous avons tester la fiabilité des mesures a travers une étude inter et intraobservateurs sur des scanners qui permet de conclure à la reproductibilité des mesures avec une variation selon les muscles étudiés (la mesure du masséter est la plus reproductible). Pour valider l'exactitude des mesures sur le scanner, à l'aide de pièce anatomique nous avons comparé l'examen scanner à l'Imagerie par Rayonnement Médicale et aux coupes anatomiques correspondantes. Dans un deuxième temps, une étude typologique permet de comparer les caractéristiques musculaires suivant la divergence squelettique de nos patients. Nous trouvons des résultats comparables à ceux de la littérature, mettant en évidence des masses musculaires plus importantes et donc plus puissantes chez les sujets hypodivergents. Les perspectives a donné à cette étude sont nombreuses, notamment envisagé de mieux connaitre les chaînes musculaires et leurs fonctionnement biodynamiquesMasticatory muscles have a considerable impact on craniofacial development and function. Since the 2000s, CT scanning associated to 3D cephalometry are used for measurement of these muscles purpose in orthodontics. In order to develop an analysis method based on measurement of masticatory muscles (masseter and pterygoid muscles) on CT scans, we have evaluated the reliability of the measurements made by two orthodontists on 3D CT scans using a cephalometric software. The comparison of intra- and interobserver estimates for repeated measurements has shown the reproducibility of all three muscles measurements, with a greater reproducibility for the masseter muscle. The accuracy of the measurements was confirmed by comparing the CT scan to MRI and corresponding anatomical sections. Finally, the masticatory muscles dimensions were related to the vertical skeletal pattern of the subjects. According to the literature, our results show larger and stronger muscles in hypodivergent subjects. CT scanning associated to 3D cephalometry could lead to a better knowledge of masticatory muscles and their biomechanical function
13
El-Nabbout, Fidele Baron Pascal Faure Jacques. "L'apport du scanner 3D en anatomie dentaire résultats et applications aux calculs d'ancrage et à la mécanique orthodontique /." Toulouse (Université Paul Sabatier, Toulouse 3), 2008. http://thesesups.ups-tlse.fr/225.
14
Spingarn, Camille. "Contribution à la biomécanique de la régénération osseuse : modélisation, simulation et applications." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAD010/document.
Анотація:
Cette thèse traite de la modélisation du remodelage osseux. Nous présentons tout d'abord un modèle général continu tenant compte de la réponse cellulaire à un stimulus mécanique. Ce modèle est appliqué à des géométries 2D et 3D macroscopiques afin de se rapprocher des problématiques réelles, ainsi que sur des géométries mésoscopiques d'os trabécullaires en 2D. Cependant la complexité du remodelage osseux ne permet pas d'avoir une approche unique de modélisation. Ainsi, dans un second temps, le cas particulier du remodelage osseux orthodontique est étudié. Un nouveau modèle spécifique est développé tenant compte de l'influence du ligament parodontal sur le remodelage osseux, et intégrant l'influence du taux d'oxygène qui contrôle les évolutions de densités cellulaires. Des données expérimentales in vitro sont extraites de la littérature et servent de données d'entrées du modèle développé afin d'obtenir l'évolution de la densité osseuse alentours d'une racine dentaire cylindrique en 3DThis work deals with modelization of bane remodeling. We present first a madel thal accounts for the cellular res panse to a mechanical stimulus in a general case at a continuous scale. This madel is applied to 2D and 3D geometries at macroscopic scale to mimic real cases, as weil as 2D trabecular-type geometries at mesoscopic scale. However, the complexity of bane remodeling does not allow a unique approach. Th us, the thesis work is focused on the particular case of orthodontie bane re mode ling. A new specifie madel is developed accounting for the influence of the periodontal ligament on orthodontie bane remodeling by integrating the oxygen concentration effect controling the evolutions of cellular densities. The cellular experimental data in vitro are extracted from the literature, and serve as input data of the developed madel in arder to ablain the evolution of bane density around the root of a 3D cylindrical tooth
15
Rothstein, Ira. "Effects of synthetic cortical bone thickness and force vector application on temporary anchorage device pull-out strength as related to clinical perspectives of practicing orthodontists." Thesis, NSUWorks, 2011. https://nsuworks.nova.edu/hpd_cdm_stuetd/56.
Анотація:
December 2011.
A thesis submitted to the College of Dental Medicine of Nova Southeastern University of the degree of Master of Science in Dentistry.
Background: Temporary anchorage devices (TADs) provide a versatile means by which orthodontic anchorage can be established without the need for patient compliance and complex force systems. Their use is predicated on their ability to remain stable throughout the course of treatment in which they are needed. This has been shown to be the result of "primary stability" which is achieved through mechanical interlocking of the screw threads with the surrounding bone immediately upon placement. Therefore, evaluating the factors that can either enhance or detract from the primary stability of TADs can serve to improve the predictability of their success. Objectives: The objectives of this study were to describe how variations in synthetic cortical bone thickness and the angle of force applied in relation to the long axis of TADs affects their stability in terms of pull-out strength, and to ascertain the perspectives of practicing orthodontists in the state of Florida on their experiences with temporary anchorage devices with regards to success and failure. Methods: For the bench top study, 90 1.5x8mm long neck Orthotechnology Spider Screws were randomly allocated to 9 groups of 10 TADs each. The 9 groups were established based on both the thickness of synthetic cortical bone (1.0, 1.5, and 2.0mm) and the angle of force vector applied relative to the long axis of the TADs (45, 90, and 1800). Pull-out testing was carried out by applying a force to the TADs via a universal testing machine (Instron, Canton, MA) at a rate of 2.0mm/minute. Real-time graphical and digital readings were recorded, with the forces being recorded in Newtons (N). Each miniscrew was subjected to the pull force until peak force values were obtained. For the 450 and 1800 tests, the force registered at the time-point of pull-out, or screw head movement of 1.5mm within the synthetic bone blocks. The determination of 1.5mm of movement was made due the dramatically erratic deflection observed by the digital and graphical readouts at precisely this point. For the survey portion of this study, A customized survey was developed for this study. The survey was composed of 12 questions, some of which were obtained from a questionnaire that was created by Buschang et al.54 The additional questions were devised by the members of this research project, with the aim of answering questions regarding the clinical experiences that practicing orthodontists experienced with TADs. Results: For the bench top study: Implants placed in 2.0mm of synthetic cortical bone and pulled at an angle of 1800 had the highest pull-out strength among all groups (258.38N), while those placed in 1.0mm of synthetic cortical bone and pulled at an angle of 900 exhibited the lowest (67.11N). When evaluated separately, a cortical bone thickness of 2.0 mm displayed the highest pull-out forces for the three angles of force application, and 1800 angle of force displayed the highest-pull-out forces for the three cortical bone thicknesses. Conversely, 1.0mm of cortical bone thickness displayed the lowest pull-out forces for the three angles of force application, and 900 angle of force displayed the highest-pull-out forces for the three cortical bone thicknesses. For the survey: The most important factor associated with TAD failure was cited as placement location by 45.7% (n=16) of respondents, while root proximity was cited as the least important factor by 35.3% (n=12) of respondents. For the site from which practitioners indicated that they experience the greatest success, 81.8% cited the palate, while 51.9% responded that they experience the highest failure rates for the posterior maxilla (distal to the cuspids). Conclusions: A synthetic cortical bone thickness of 2mm and pull forces applied parallel to the long axis of TADs resulted in the greatest resistance to pull-out.
16
Paetyangkul, Anchalee. "The extent of root resorption after the application of continuous and controlled orthodontic forces for 12 weeks: a micro-ct scan study." Thesis, Faculty of Dentistry, 2007. http://hdl.handle.net/2123/4287.
17
Rex, Teriko. "A Comparative Quantitative Analysis Of The Mineral Composition Of Human Premolar Cementum After The Application Of Orthodontic Forces m- An Epma Study." Thesis, Faculty of Dentistry, 2002. http://hdl.handle.net/2123/4151.
18
McKernan, Susan Christine. "Dental service areas: methodologies and applications for evaluation of access to care." Diss., University of Iowa, 2012. https://ir.uiowa.edu/etd/1362.
Анотація:
Significant efforts have been undertaken in medicine to identify hospital and primary care service areas (eg, the Dartmouth Atlas of Health Care) using patient origin information. Similar research in dentistry is nonexistent. The goal of this dissertation was to develop and refine methods of defining dentist service areas (DSAs) using dental insurance claims. These service areas were then used as spatial units of analysis in studies that examined relationships between utilization of oral health services, dentist workforce supply, and service area characteristics.
Enrollment and claims data were obtained from the Iowa Medicaid program for children and adolescents ages 3-18 years during calendar years 2008 through 2010. The first study described rates of treatment by orthodontists in children ages 6-18 years. Orthodontic DSAs were identified by small area analysis in order to examine regional variability in utilization. The overall rate of utilization was approximately 3%; 19 DSAs were delineated. Interestingly, children living in small towns and rural areas were significantly more likely to have received orthodontic services than those living in metropolitan and micropolitan areas.
The second study identified 113 DSAs using claims submitted by primary care dentists (ie, general and pediatric dentists). Characteristics of these primary care DSAs were then compared with counties. Localization of care was used as a measure of how well each region approximated a dental market area. Approximately 59% of care received by Medicaid-enrolled children took place within their assigned service area versus 52% of care within their county of residence.
Hierarchical logistic regression was used in the final study to examine the influence of spatial accessibility and the importance of place on the receipt of preventive dental visits among Medicaid-enrolled children. Children living in urban areas were more likely to have received a visit than those living in more rural areas. Spatial accessibility assessed using measures of dentist workforce supply and travel cost did not appear to be a major barrier to care in this population.
More studies are needed to explore the importance of spatial accessibility and other geographic barriers on access to oral health services. The methods used in this dissertation to identify service areas can be applied to other populations and offer an appropriate method for examining revealed patient preferences for oral health care.
19
Wu, Andy Tzong Jong. "The extent of root resorption following the application of light (25g) and heavy (225g) controlled rotational orthodontic forces for 4 weeks: a micro-CT study." Thesis, The University of Sydney, 2009. https://hdl.handle.net/2123/28194.
Анотація:
In 1932 Beck and Marshall defined root resorption as the destruction of formed tooth
structure. Root resorption results in the loss of substance from dentine or cementum
and can present as either a physiological or pathological process. Physiological root
resorption can occur in both deciduous and permanent dentition. Root resorption of
the deciduous dentition is a normal and essential physiological process that facilitates
natural exfoliation. Pathological resorption is an inflammatory process that is
triggered by numerous factors.
Root resorption following orthodontic treatment is intimately associated with the
biological processes that occur during tooth movement. To date, the mechanism of
orthodontically induced inflammatory root resorption (henceforth referred to as
OIIRR) has not been fully understood. The pathological process is related to local
injury of the periodontal ligament associated with the removal of hyalinised tissue.
This process has been found to take place when local areas of the periodontal
ligament are overcompressed. The phenomenon is widely known as OIIRR and is
often unpredictable; it is an inevitable pathological consequence of orthodontic tooth
movement that compromises the success of orthodontic treatment.
The incidence of OIIRR ranges from 73% to 100% in recent studies} and its
prevalence has been shown to increase with orthodontic treatment. Experimental
research concludes that all human teeth develop resorption lacunae on the pressure
side of the root surface shortly after application of orthodontic forces.
20
Shi, Jianwei [Verfasser], and Andrea [Akademischer Betreuer] Wichelhaus. "Establishment and application of an in vitro method to investigate the intercellular communication between cells involved in orthodontic tooth movement / Jianwei Shi ; Betreuer: Andrea Wichelhaus." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1187135445/34.
21
Alcheikh, Anas. "Réponse des ostéoblastes sur des surfaces en titane modifiées par greffage des groupements ioniques pour des applications cliniques en odontologie (chirurgie, orthodontie et implantologie)." Paris 13, 2010. http://www.theses.fr/2010PA132019.
Анотація:
Le titane est un matériau de choix pour des applications orthopédiques et dentaires. Afin de conférer aux surfaces de titane des propriétés antibactériennes et améliorer son potentiel d’ostéointegration l’équipe de LBPS a proposé la fonctionnalisation par greffage de polymères « bioactifs ». Notre travail s’intègre dans cette thématique ; Nous avons étudié à la fois l’adhérence de S. Aureus et la réponse des ostéoblastes sur des surfaces de titane greffées de poly(styrène sulfonate de sodium) polyNaSS. Les surfaces en titane bioactives ont été réalisées par greffage de polyNaSS obtenues par copolymérisation radicalaire Trois types de surface en titane ont été utilisées pour les tests biologiques : titane non modifié, titane oxydé, titane greffé. L’adhérence bactérienne a été étudiée sur les surfaces de titane greffées et non greffées, pré-adsorbées ou non de protéines plasmatiques. Le comptage des bactéries était suivi par marquage des bactéries à la fluorescéine puis quantification par analyse d’images. En effet, nous avons montré que la modification des surfaces de titane par greffage d’un polymère « bioactif » tel que le poly(styrène sulfonate de sodium) permet d’inhiber (> 70 %) l’adhérence de S. Aureus. Cette propriété inhibitrice implique probablement la quantité et/ou la conformation des protéines adsorbées qui sont susceptibles de médier l’adhérence bactérienne. Parallèlement, nous avons exploré la réponse ostéoblastique à l’aide de cellules de calvaria de fœtus de rat en culture. Les résultats ont montré que le greffage de poly(styrène sulfonate de sodium) n’altère pas le nombre de cellules adhérentes sur le titane, ni leur morphologie. Il n’interfère pas non plus avec la prolifération, comme l’atteste la cinétique de la prolifération des cellules similaire sur les trois surfaces testées. En revanche, l’activité spécifique de la phosphatase alcaline sur la surface greffée est significativement supérieure (p<0,01) à celles observées sur les surfaces contrôles, Les nodules de minéralisation ont été visibles sur les trois surfaces de titane testées. Toutefois, la somme des aires de la surface sur le titane greffé était significativement (p<0,05) supérieure a celle observé sur la surface de titane oxydé et non modifié. En conclusion, le greffage de surfaces en titane avec ces polymères bioactifs sulfonates d’une part inhibe l’adhésion de S. Aureus et d’autre part non seulement n’interfère pas avec l’adhésion et la prolifération mais stimule la différentiation des cellules ostéoblastiques. Ces surfaces pourraient donc être intéressantes en application clinique pour les revêtements des implants en particulier dans le domaine de l’orthopédie afin de prévenir les infections peri-implantairesTitanium is a material of choice for orthopedic and dental applications. To confer with titanium surfaces antibacterial properties and improve its potential for osseointegration LBPS team proposed the functionalization of polymers "bioactive". Our work fits into this theme, we have studied both the adherence of S. Aureus and the response of osteoblasts on titanium surfaces grafted with poly (styrene sulfonate) polyNaSS. Bioactive titanium surfaces were performed by grafting polyNaSS obtained by radical copolymerization Three types of titanium surface were used for biological tests: non-modified titanium, oxidized titanium, titanium grafted. The bacterial adhesion was investigated on titanium surfaces grafted and ungrafted, pre-adsorbed plasma proteins or not. Counting of bacteria was followed by labeling bacteria with fluorescein and quantification by image analysis. Indeed, we showed that the modification of titanium surfaces by grafting a polymer "bioactive" such as poly (styrene sulfonate) can inhibit (> 70%) adherence of S. Aureus. This property probably involves inhibiting the amount and / or conformation of adsorbed proteins that may mediate bacterial adhesion. In parallel, we explored the response using osteoblastic cells in fetal rat calvaria in culture. The results showed that the grafting of poly (styrene sulfonate) does not alter the number of adherent cells on titanium, or morphology. It does not interfere either with proliferation, as evidenced by the kinetics of cell proliferation similar on all three surfaces tested. However, the specific activity of alkaline phosphatase on the grafted surface was significantly higher (p <0. 01) than those observed on control surfaces, mineralization nodules were visible on the three titanium surfaces tested. However, the sum of the areas on the titanium surface grafted was significantly (p <0. 05) greater than that observed on the surface of oxidized titanium and unmodified. In conclusion, the grafting of titanium surfaces with these bioactive polymers sulfonates one hand inhibits the adhesion of S. Aureus and the other not only does not interfere with the adhesion and proliferation but stimulates differentiation of osteoblastic cells. These surfaces could be interesting for clinical application in coatings of implants, particularly in the field of orthopedics to prevent peri-implant infections
22
Lavernhe, Patrick. "La photopolymérisation en application orthodontique." Toulouse 3, 2007. http://www.theses.fr/2007TOU30013.
Анотація:
Deux dispositifs de photopolymérisation (halogène/LED), deux types de colle pour le collage orthodontique (un composite : Transbond XT, un CVI hybride : Fuji Ortho LC II) sont évalués. Les colles sont photopolymérisées 20 s et 40 s avec la lampe halogène et 5 s, 10 s, 15 s, 20 s et 40 s avec la lampe LED. L'étude du joint de colle se fait par des essais de dureté, de mesures thermiques et des essais de traction/cisaillement. L'augmentation du temps de photopolymérisation améliore les résultats de dureté et de solidité du collage quelque soit le type de lampe sauf avec le CVI pour lequel au-delà de 15 s, les résultats diminuent. La photopolymérisation augmente de 2°C la température au niveau de la dent et de + 20°C au niveau du bracket avec la lampe halogène. Les lampes LED sont tout à fait performantes. Le CVI a une facilité d'utilisation clinique, il renforce la résistance aux lésions carieuses, ils ne doivent pas être photopolymérisés plus de 15 s, et reste en deçà des performances adhésives des compositesTwo photopolymerization processes (halogen and LED), two cement types for orthodontic bonding – a composite one : Transbond XT and a CVI hybrid one: Fuji ortho LC II – are assessed; cements are photopolymerised between 20 and 40 s with a halogen lamp and for 5 10 15, 20 or 40 s with a LED lamp. Studying the cement joint is by hardness, thermic measures and traction/ Shearing trials. Increasing photopolymerisation time improves hardness results and bonding resistance whatever the type of lamp, except for CVI, for which beyond 15 s, results go decreasing. Photopolymerisation increases tooth temperature by 2°C and with a halogen lamp, bracket temperature is increased by + 20°C. LED lamps are quite satisfactory. CVI has an easy clinical use, it reinforces resistance to carious lesions, mustn't be photopolymerised for more than 15 s and remains short of the adhesive performances of composites
23
El-Nabbout, Fidele. "L'apport du scanner 3D en anatomie dentaire : résultats et applications aux calculs d'ancrage et à la mécanique orthodontique." Toulouse 3, 2007. http://thesesups.ups-tlse.fr/225/.
Анотація:
Cette étude est une mise au point sur les valeurs d'ancrage en orthodontie et leurs influences sur les choix thérapeutiques. Un échantillon de 120 sujets a été analysé. L'utilisation du scanner 3D et des logiciels C2000-Cépha et Cépha3DT, nous permet de faire la sélection des dents ensuite, calculer certains paramètres d'anatomie dentaire tels que les volumes radiculaires, ces derniers peuvent servir comme éléments essentiels pour définir l'ancrage en orthodontie. A partir de cette sélection, le logiciel C2000 réalise une reconstruction ; ceci permet la détermination de paramètres indispensables dans l'étude des dents et de leur rôle dans le choix des attitudes thérapeutiques en orthodontie : - les valeurs d'ancrage des dents et des groupes de dents, - la localisation tridimensionnelle des centres de résistance de groupe. Les données anatomiques individuelles et par groupe de dents éclairent d'un jour nouveau certaines options thérapeutiques. Les valeurs guides sont calculées et comparées à celles proposées dans la littérature. Les nouveaux coefficients d'ancrage proposés remettent en cause certaines attitudes thérapeutiques en orthodontie, et cela nous induit à une attitude thérapeutique plus prudente quelquefois. L'utilisation pratique de ces centres de gravité de groupe, trouve une application clinique immédiate dans les calculs de mécanique conventionnelle et dans les calculs des mécaniques s'appuyant sur des ancrages absolus, c. à. D. Sur les micros-visThe present study is an update on anchorage values in orthodontics and their impact on treatment options. The chosen sample included 120 subjects. 3D tomodensitometry using C2000-Cepha and Cepha 3DT software, calculated tooth anatomy parameters such as root volume which can serve as a basis for defining anchorage in orthodontics. According to this selection, the software C2000 achieves a reconstruction; it permits the determination of essential parameters in the survey of teeth and their role in the therapeutic attitude choice in orthodontics: - Anchorage values of a tooth and groups of teeth, - 3D localization of resistance centers groups. The individual anatomical data for each dental and groups of teeth enlighten certain therapeutic options. The reference values were calculated and compared with those available in the literature. They challenge a number of current approaches in orthodontic treatment, and it sometimes misleads us to a more prudent therapeutic attitude. The use of these group gravity centers in practice, find an immediate clinical application in counts of conventional mechanics and in counts of mechanics relying on the absolute anchorages, means the mini-screws
24
Hasanat, Watraat Unmona. "Utilization of a new web-based application for case difficulty assessment as a predictor for procedural errors in nonsurgical root canal treatment." Scholarly Commons, 2021. https://scholarlycommons.pacific.edu/dugoni_etd/15.
Анотація:
Introduction: There are currently no established guidelines to determine which cases general practitioners should refer to an endodontist for root canal treatment. The American Association of Endodontists (AAE) has developed the EndoCase mobile application (ECA), which utilizes either a full or abridged rubric to assign case difficulty level and provide referral guidelines to general practitioners and dental students. Objective: The objective of this study was to determine whether the abridged criteria of the EndoCase application can help predict the incidence of procedural errors in nonsurgical root canal treatment of mandibular molars in an undergraduate dental clinic based on the difficulty level. Methods: A list of patients who received primary root canal treatment on mandibular first molars in the undergraduate dental clinic from 2015-2020 was obtained. Ninety patients qualified for inclusion. Case difficulty level was assessed using the ECA by three providers with differing levels of experience. Incidence of procedural errors was determined from post-operative radiographs by two calibrated independent observers. Results: The most common endodontic mishaps were errors during access cavity preparation followed by the presence of voids in the root filling, with an incidence of 54.4% and 45.6%, respectively. There were no significant differences regarding case difficulty level and the incidence of total procedural errors nor number of treatment visits. Of the individual error types, the presence of obturation >2mm short of the radiographic apex was weakly correlated with case difficulty level (r = 0.226, pConclusion: There is minimal correlation between the difficulty level of mandibular molars determined by the ECA and the number of treatment visits or overall incidence of procedural errors.
25
Liu, Yanzhi. "Effects of modeling methods on the finite element analysis results of orthodontic applications." Thesis, 2017. https://doi.org/10.7912/C23W9R.
26
Hung, Chih-Ying, and 洪志穎. "Application of layered double hydroxides in dental orthodontic resin." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/g6a948.
27
Ford, Heather Nicole. "Nitric Oxide Changes in Gingival Crevicular Fluid Following Orthodontic Force Application." Thesis, 2013. http://hdl.handle.net/1807/42838.
Анотація:
Nitric oxide (NO) plays a role in regulating the rate of orthodontic tooth movement (OTM) in rat models; however, in humans this role remains less clear. In this study, samples of gingival crevicular fluid (GCF) were collected from each maxillary central incisor and first and second molar immediately before (T0), 1 hour after (T1), and 3-4 days after (T2) application of light orthodontic forces in thirteen male participants (ages 11-18 years) undergoing orthodontic therapy. NO levels were measured in each GCF sample, and significantly higher NO levels (p<0.05) were found at T1 at the buccal surfaces of the central incisors when compared to the posterior teeth. The results indicate a possible role for NO in OTM at the pressure sites of incisors at early time points. Further studies are required to determine whether NO levels in the PDL of human teeth are affected by the magnitude of an applied force.
28
lu-jen-ki and 盧仁凱. "Application of Computer Aided Design in Orthodontic System - Model Segmentation." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/39684293900365253209.
Анотація:
碩士國立臺灣科技大學
機械工程系
90
This thesis aims to propose and implement the method of using a number of polygons to extract a specific region from massive scanned data points. The 3D scanned data is firstly projected onto the 2D view plane. The method of dividing a polygon into compound triangles is then applied to partition the data points into individual regions. In this thesis, the method is discussed and the implementation results are applied to assist the extraction of teeth of interest in corrective treatment of teeth. Its steps include the input of scanned data of teeth and the drawing of polygons in different 3D views to extract the data points of to-be-corrected teeth. As for system development, Microsoft Visual C++, MFC and OpenGL are used as the tools to evolve a Windows-based prototype system, verifying the feasibility of model segmentation with the assistance of computers.
29
Pei-yi, Yeh, and 葉佩怡. "Application of Computer Aided Design in Orthodontic Treatment - Preliminary Study." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/29434624389933785827.
Анотація:
碩士國立臺灣科技大學
機械工程系
90
This thesis aims to apply the techniques of computer-aided design to simulate the procedure of corrective treatment of teeth, which is the first step of manufacturing of tooth aligner. The workflow includes the following steps: 1.Read in the scanned data points of the teeth. 2.Use 4 points or 6 points to index the to-be-corrected tooth and its adjacent teeth. Original segment and target segment are formed from the indexing. Based on the relative location of the two segments, the amount of translating the to-be-corrected tooth can be found automatically and point data of the tooth are moved accordingly. 3.The to-be-corrected tooth rotates a certain angle input by the user using the original segment as the axis of rotation. 4.The transformation between the original and final locations of the tooth is analyzed and recorded for use of subsequent procedures. With the results, dentists should have more accurate data for better treatment. As for system development, Microsoft Visual C++, MFC and OpenGL are used as the tools to evolve a Windows-based prototype system, verifying the feasibility of orthodontic treatment using computers.
30
Li, Chih-Wei, and 李志偉. "The combination application with perio-prosthesis,dental implant and orthodontic treatment." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/34989623893115781261.
Анотація:
碩士高雄醫學大學
牙醫學研究所碩士在職專班
95
Periodontal prosthesis, as the definition from Dr. Amsterdam, emphasizes the necessity of restorative prosthesis for the dentition with advanced periodontal disease. With the help by the new development of new techniques like guided tissue regeneration, guided bone regeneration, enamel matrix derivatives and PRP (platelet rich plasma) we can keep more teeth and achieve better results than before. In the treatment of severe chronic periodontitis (SCP), we should apply the same operative dentistry and prosthetics principles like we do with general dentition with some modification because the differences between SCP involved dentition and normal dentition. We should have multidirectional consideration about the involvement of patients’ will ,time, economic situation, medical and dental situation.. This paper includes 11 clinical cases, aged from 30 to 50. The clinical diagnosis includes generalized or localized chronic periodontitis and localized gingival enlargement. To accomplish the demands of health and function, for these cases we had done orthodontic treatment, endodontic treatment, periodontal surgery, oral surgery and even implants. The prosthesis including tooth-supported fixed denture, adhesive bridge, implant-supported fixed denture, conventional removable partial denture and telescopic crown retained overdenture. Until the end of active treatment, we and the patients have achieved significant improvements in the periodontal indices (plaque index, gingival index), probing pocket depth, and tooth mobility and in some cases we can see bone regeneration. The patients are satisfied the results with their prosthesis. Among these cases, all have been finished and followed for more than one year, for some even up to 3.5 years; their treatment goals have been followed and found fulfilled. But to achieve a further good long-term prognosis we have to do frequent hygiene recalls and prosthetic maintenance.
31
Ko, Hsiu-Ching, and 柯秀靜. "Surface Treatment of 316L stainless steel in the application of orthodontic miniscrews." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/03570311190151453447.
Анотація:
碩士國立臺灣大學
臨床牙醫學研究所
103
With the advances of dental implants, temporary skeletal anchorage devices have now become established orthodontic anchorage aids and launched a new era for clinical orthodontic therapy. In recent years, numerous publications have investigated multiple factors affecting success rates of orthodontic mini-screws, such as shape design, material science, or surface topography. The success rate of 316L stainless steel orthodontic miniscrews was found to be lower than titanium alloy, and our research goal was to make surface modification by coating a TiO2 thin film on 316L stainless steel, which aimed to improve the biocompatibility and induce osseointegration. The 316L stainless steel plates were used in this study to test mechanical conditions. The experimental variables were included as follow: 1. Coating methods : ion-beam assisted electron beam evaporation and sol-gel method for titanium;2 Coating thickness, ranging from 30 to 500 nm; 3. Surface roughness. The composition and crystalline phase were analyzed by Energy Dispersive Spectrometer (EDS) and X-ray diffraction analyzer (XRD). The surface and cross-section of films were examined by scanning electron microscope. And the color three-dimensional laser scanning analyzer was used to analyze the surface roughness of films. Finally, the film adhesion under various coating parameters was evaluated by a scratch test machine. Besides, all the data would compare with the previous results of magnetron sputtering and produce a comprehensive view of those results. The study results showed that TiO2 thin film with good quality and dense structure can be coated on 316L stainless steel by magnetron sputtering, electron beam evaporation, and sol-gel method. The magnetron sputtering can produce best results regarding to film adhesion and crystallization structure. The sol-gel method also could produce thin film with good adhesion property and crystallization structure after rapid thermal annealing. However, the ion-beam assisted electron beam evaporation can produce thin film with dense structure, but the adhesion property was poorer than magnetron sputtering and sol-gel method. Besides, the film thickness played an important role in the adhesion property, and the surface roughness was not altered by the coating.
32
Chu, Ting-Wei, and 朱庭緯. "Surface treatment of 316L stainless steel in the application of orthodontic miniscrews-Mechanical analysis." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/ed8sz5.
Анотація:
碩士國立臺灣大學
臨床牙醫學研究所
101
In recent years, with the increased application of the orthodontic bony anchorage, it had been proposed to improve the clinical success rate of orthodontic mini-screws by a variety of modification of screw geometry, material or surface morphology. Our intention in this study was to modify the surface of stainless steel by surface coating of biocompatible films and improve the biocompatibility and the capability of bone integration. The 316L stainless steel plates with the same composition of orthodontic stainless steel screws were used in this study to eliminate variables and simplify the mechanical testing conditions. The experimental variables were included as follow: 1. Coating materials. Titanium and titanium dioxide. 2. Coating methods. Magnetron sputtering or sol-gel method for titanium dioxide film. And magnetron sputtering or electron beam evaporation method for titanium film. 3 Coating thickness. With the range of 30 to 500 nm. 4. Surface roughness. The composition and crystalline phase were analyzed by electron probe microanalyzer (EPMA) and X-ray diffraction analyzer (XRD). The surface and cross-section of films were examined by field emission scanning electron microscope. And the color three-dimensional laser scanning analyzer was used to calculate the surface roughness of films. Finally, the film adhesion under various coating parameters was evaluated by a scratch test machine. The study results show that the titanium film could be made by the magnetron sputtering or the electron beam evaporation method. However, poor adhesion between the titanium coating and the substrate was noted by the scratch test. On the other hands, regardless of the coating methods by magnetron sputtering or sol-gel method, the v titanium dioxide film performed good adhesion properties. In addition, the film thickness and surface roughness does affect the property of film adhesion. The ability of spalling resistance was improved by increased coating thickness and by increased surface roughness. But the crack resistance property was weaken with increase of the surface roughness of films.
33
O'Toole, Michael. "Impact of Orthodontic Mini-screw Angulation Relative to Direction of Force Application on Stability, Movement, and the Peri-implant Interface." Thesis, 2011. http://hdl.handle.net/1807/31375.
Анотація:
The purpose of this study was to determine the impact of insertion angle of orthodontic mini screws on the stability and resistance to movement of the mini screw, and on the peri-implant interface. Three orthodontic mini screws were placed in each tibia of six New Zealand white rabbits bilaterally (N=36), with randomized angulation (65° away, 65° toward, or 90° to the direction of applied force). After two weeks, two orthodontic mini screws within each tibia were loaded with a 200g Nitinol closed-coil spring for up to 14 days. No statistically significant differences were found among the variably angulated loaded and unloaded orthodontic mini screws in the amount of movement or change in angulation demonstrated over the experimental period. Micro CT analysis revealed no clinically significant differences in the amount of cortical bone-to-implant contact. Mini screw placement angulation seems to have minimal impact on stability and migration of orthodontic mini screws over time.
34
Bogowicz, Paul Joseph. "Fully sequential monitoring of longitudinal trials using sequential ranks, with applications to an orthodontics study." Master's thesis, 2009. http://hdl.handle.net/10048/531.
Анотація:
Thesis (M. Sc.)--University of Alberta, 2009.Title from pdf file main screen (viewed on Aug. 27, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science in Statistics, Department of Mathematical and Statistical Sciences, University of Alberta." Includes bibliographical references.
35
Bar-Zion, Yossi. "Three-dimensional characterization of maxillary molar displacement subsequent to headgear treatment with respect to time and force of application : development and pilot test of a novel study method /." 2000. http://purl.fcla.edu/fcla/etd/amt2424.
36
Caetano, José Pedro Pinto Martinho Fernandes. "Efeito das forças ortodônticas nas células estaminais da polpa dentária." Master's thesis, 2017. http://hdl.handle.net/10316/82759.
Анотація:
Trabalho de Projeto do Mestrado Integrado em Medicina Dentária apresentado à Faculdade de MedicinaIntrodução e objetivos: A aplicação de forças ortodônticas à polpa tem efeitos ainda pouco conhecidos. Como as células estaminais da polpa dentária (DPSC) são responsáveis pela manutenção da sua homeostase, este estudo tem como objetivo avaliar os efeitos da aplicação destas forças nesta população celular.Materiais e métodos: Pré-molares sujeitos a forças ortodônticas foram divididos em 4 grupos (T0 controlo, 1 semana T1, 2 semanas T2 e 3 semanas T3) para estudo histológico e de imunohistoquímica com anticorpos específicos para células estaminais. Resultados: Em T1 houve um aumento na vascularização e uma maior densidade celular imediatamente subjacente à camada odontoblástica. Houve formação de tecido mineralizado, nomeadamente osteodentina e cemento. Em T2 verifica-se a presença de um certo grau de hiperémia vascular que se considera ser inferior ao analisado em T1 e observaram-se pulpólitos em algumas amostras, já não visíveis em T3. Em T3 o aspeto da polpa era similar à de T0. Apenas em T1 foi observada a expressão de Oct3/4 e Nanog em forma de cluster na região sub-odontoblástica. Discussão: A observação da expressão de Oct3/4 e Nanog à 1ª semana parece indicar que o sistema responde à agressão “força ortodôntica” com a proliferação das DPSC. A não observação de expressão à 2ª semana parece indiciar que, nesta altura, as DPSC se terão diferenciado protetivamente em células capazes de produzir tecidos mineralizados. À 3ª semana tudo indica que o sistema pulpar já se encontra em reparação.Conclusões: Como mecanismo de sobrevivência, o sistema pulpo-dentinário responde à agressão primeiro com proliferação e depois com diferenciação das DPSC em células com capacidade de síntese de tecidos duros, havendo necessidade de mais estudos com reativação da força ortodôntica/polpa. Implicações clínicas: A formação de pulpólitos e osteodentina poderá eventualmente produzir perda de vitalidade pulpar.
Introduction and Aim: The effects of application of orthodontic force to the dental pulp are still unclear. Since dental pulp stem cells (DPSC) are responsible for the maintenance of pulp homeostasis, this study aims to evaluate the effects of the application of orthodontic forces in this cell population.Materials and Methods: Pre-molars subjected to orthodontic forces were divided into 4 groups (control T0, 1 week T1, 2 weeks T2 and 3 weeks T3) for histological study and immunohistochemistry with specific stem cells antibodies.Results: At T1 there was an increase in vascularization and a higher cell density immediately under the odontoblastic layer. There was formation of mineralized tissue, namely osteodentin and cementum. In some samples of T2 was verified the presence of a certain degree of vascular hyperemia considered to be lower to the one analyzed in T1 and pulp calcifications were observed being no longer visible at T3. At T3 the overall appearance of the pulp was similar to that of T0. Only at T1 the expression of Oct3/4 and Nanog in the form of cluster in the subodontoblastic region was observed.Discussion: The expression of Oct3/4 and Nanog at T1 seems to indicate that the system responds to the "orthodontic force" aggression with DPSC proliferation. The absence of antibody expression at T2 seems to indicate that DPSC have already differentiated protectively in cells capable of producing mineralized tissues. At T3 the pulp seems to be already under repair. Conclusion: As a survival mechanism, the pulp-dentin system reacts to the orthodontic force first with proliferation and afterwards with differentiation of DPSC in cells capable of producing calcifications. Further studies with orthodontic force/pulp reactivation are necessary.Clinical Implications: Presence of pulp calcifications and osteodentin may lead to loss of vitality.
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Wang, Chih-Hao, and 王志浩. "The application of the 3D laser scanning to the micro distortion survey - example as the face distortion of orthodontics." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/67505695469338545219.
Анотація:
碩士逢甲大學
環境資訊科技研究所
93
Puts the project survey idea on in the person face micro distortion survey, rectifies with the dentist cooperation and using the patient tooth jaw took the actual case, the use laser scanning technology, after discovers the patient to accept the tooth jaw to rectify the face distortion quantity, and using this pattern, forecast the future sickness will accept the tooth jaw to rectify after the distortion quantity, the union image sticks on the technology, after will be able fast to obtain completes the treatment the 3D facial features outward appearance simulation before, will cause doctor and the patient can in rectify the plan to start to know in advance sickness will rectify after the appearance, will take advantage of this enhances between doctor and patient''s communication and the interaction. Scans the person face by the 3D three-dimensional laser scan with on lower jaw linking model, completes to the 3D several images facial features outward appearance simulation, this research around spend for more than 6 months to complete the flow formulation and the analysis modeling. This article proposed this method supplies the reference, future will be allowed to depend on according to this the way work, the soft hardware expert will be supposed to be allowed to a month, after to complete the treatment the facial features outward appearance simulation.
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Silva, Ana Bárbara Nunes de Almeida e. "Aplicações clínicas da tomografia computorizada de feixe cónico em pacientes ortodônticos." Master's thesis, 2018. http://hdl.handle.net/10316/82189.
Анотація:
Trabalho Final do Mestrado Integrado em Medicina Dentária apresentado à Faculdade de MedicinaIntrodução: Na Medicina Dentária e particularmente em Ortodontia, as técnicas radiológicas convencionais, como a radiografia panorâmica, a telerradiografia lateral e frontal da face, as radiografias periapicais e oclusais ainda são as mais frequentemente requisitadas pelo profissional. A necessidade de métodos mais fidedignos e com menores distorções e sobreposições levam o médico-dentista a recorrer a alternativas tecnológicas, pouco invasivas e rápidas, que possam minimizar as sequelas da exposição à radiação. A tomografia computorizada de feixe cónico (TCFC) tem vindo a destacar-se neste âmbito. Este exame complementar permite uma avaliação exaustiva dos detalhes anatómicos das estruturas crânio-faciais, sendo uma mais valia no diagnóstico e monitorização do tratamento ortodôntico.Há que salientar, de entre a vasta área de aplicações clínicas da TCFC em ortodontia, as que mais se destacam: o diagnóstico/localização de dentes inclusos, os estudos cefalométricos, o planeamento na colocação de dispositivos expansores maxilares e micro-implantes, os tratamentos ortodôntico-cirúrgicos combinados e o diagnóstico de malformações crânio-faciais. Transversalmente aos itens supracitados e no contexto médico-legal, assume-se o médico dentista com um papel avaliador e tradutor da informação. Neste âmbito a TCFC é aplicada no mais correto exercício da justiça.Objetivo:Esta revisão da literatura tem por objetivo clarificar a relevância da TCFC no âmbito da ortodontia, face às aplicações clínicas desta técnica em situações de maior complexidade de diagnóstico e tratamento. Além disto, abordar de forma genérica as técnicas radiográficas convencionais utilizadas em Ortodontia, referindo as diferenças entre elas, particularmente no que toca à dose de radiação aplicada.Metodologia de Pesquisa: Foi realizada uma pesquisa eletrónica na base de dados MEDLINE/PubMed, com os termos ‘’orthodontics’’, ‘’cone-beam computed tomography’’ e ‘’orthodontic application’’. Às publicações identificadas, foram aplicados os filtros: resumo disponível online, versão “Full text”, publicações em língua inglesa ou portuguesa dos últimos 10 anos e estudos em humanos. Os títulos e resumos dos artigos foram seleccionados com base nos critérios de inclusão e exclusão. Outra literatura relevante para esta revisão foi adicionada manualmente.Resultados: Foram identificados 1059 artigos. Considerando os critérios de exclusão e a análise da relevância dos trabalhos, consideramos para análise e elaboração desta revisão, 84 referências bibliográficas. Conclusão: Há evidência científica de que esta técnica é uma ferramenta fundamental para um diagnóstico credível, em situações de elevada complexidade, quando nenhuma outra técnica convencional o permite.
Introduction: In dentistry and particularly in orthodontics, conventional radiological techniques such as panoramic radiography, frontal and lateral teleradiography of the face, periapical and occlusal radiographs are still the most frequently requested by the professional. The need for more reliable methods and with less distortions and overlaps lead the dentist to resort to technological alternatives, which are faster and not invasive , that can minimize the sequelae of radiation exposure. Cone-beam computed tomography (CBCT) has become very important in this field. This complementary examination allows an exhaustive evaluation of the anatomical details of the craniofacial structures, becoming an huge value in the diagnosis and monitoring of orthodontic and / or surgical treatment.The wide range of clinical applications of CBCT in orthodontics should be emphasized: from orthognathic surgery, cephalometric studies, diagnosis / location of included teeth, planning of placement of maxillary expanders and micro-implants, diagnosis of cranial malformations facial and tumors of the oral cavity. Transversally to the already mentioned items and in the medico-legal context, the dentist is assumed to have an evaluating role and an information translator. In this context the TCFC is applied in the most correct exercise of justice.Objective: This review aims to clarify the clinical applications of this technique, in orthodontics, in situations of greater complexity of diagnosis and treatment. In addition, to know a little about conventional radiological techniques and the differences between them, particularly with regard to radiation doses.Research Methodology: An electronic search was performed in the MEDLINE / PubMed database, with the terms Mesh '' orthodontics '' AND '' cone-beam computed tomography ''; '' Orthodontic application '' AND '' cone-beam computed tomography '', "Full text" version, in English and Portuguese, were published and published in the last 10 years. Titles and abstracts of articles were crawled based on inclusion and exclusion criteria. Other relevant literature for this review was added manually.Results: There were 1059 articles. Considering the exclusion criteria and the analysis of the relevance of the work, we obtained 84 bibliographic references for the review. Conclusion: There is scientific evidence that this technique is a fundamental tool for a credible diagnosis, in situations of high complexity, when no other conventional technique allows it.
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Tan, Daniel. "The effect of mechanical vibration (Acceledent 30Hz) applied to the hemimaxilla on root resporption and tooth movement after application of orthodontic force. A micro CT study." Thesis, 2011. http://hdl.handle.net/2123/7924.