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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.
1

An assessment of arch dimensional change with self-ligating brackets : systematic review and a randomised controlled trial

Fleming, Padhraig Seamus January 2013 (has links)
The purposes of this study were to systematically review the evidence on the clinical use of self-ligating brackets (SLBs) and the validity of digital models, and to compare maxillary arch dimensional change during alignment with conventional brackets (CBs) and active or passive self-ligation in a clinical study. In the systematic reviews, multiple databases were searched, study selection, quality assessment and data extraction were performed, and meta-analyses conducted, where appropriate. In a laboratory study a technique to measure molar inclination change incorporating digital models was developed and validated. A multicentre, 3- arm parallel-group trial was conducted with 96 patients aged 16 and above randomly allocated into 3 equal groups (OvationTM, InOvationCTM or Damon QTM) and undergoing alignment with a DamonTM wire sequence for at least 34 weeks. Meta-analyses demonstrated no difference in arch dimensional changes between SLBs and CBs; however, a greater treatment time was found with self-ligation (2.2 months, 95% CI: 0.4, 3.98). The validity of direct measurement on digital models was confirmed in the other review, although meta-analysis was not possible. Complete data were obtained from 87 subjects in the trial. Bracket type had no significant effect on transverse dimensional changes with no difference in inter-molar width between passive self-ligation and CBs (0.32mm, 95% CI: -0.41, 1.05, p= 0.38) or active selfligation (0.4mm, 95% CI: -0.31, 1.11, p= 0.27). Incisor inclination changes with Damon QTM could not be differentiated from the conventional system (0.44 degrees, 95% CI: - 1.93, 2.8, p=0.71) or InOvationCTM (-0.22 degrees, 95% CI: -2.58, 2.14, p=0.85). Based on the systematic reviews, measurement of digital models is a valid alternative to plaster models, while little evidence to support the use of self-ligation was found. In the clinical trial no differences in arch dimensional changes during alignment between CBs and either active or passive self-ligation was found.
2

The effect of wire alloy on torque expression in metallic self-ligating orthodontic brackets

Archambault, Amy Unknown Date
No description available.
3

The effect of wire alloy on torque expression in metallic self-ligating orthodontic brackets

Archambault, Amy 11 1900 (has links)
The objective of this thesis was to identify differences in torque expression between three brands of metallic self-ligating brackets with stainless steel, TMA® and CuNiTi® wire and to compare active and passive designs. 150 of each Damon-3MX (Ormco Inc, Orange, CA, USA), SPEED (Strite Industries, Cambridge, Ontario, Canada) and In-Ovation-R (GAC, Bohemia, NY, USA) brackets were measured for torque expression (Nmm) in an Air-shields Isolette® infant incubator. Torque expression in SPEED and In-Ovation-R brackets began at approximately 7.5° vs. 12° with Damon-3MX. Clinically applicable torque expression (5-20Nmm) was observed from approximately 15-30° in SPEED & In-Ovation-R brackets with stainless steel wire. In Damon-3MX, comparable torsional moments were expressed from 18-30°. With TMA wire, SPEED exerted clinically applicable torsional moments from 18-39°, In-Ovation-R from 21-39° and Damon-3MX from 21-42°. For CuNiTi wire, SPEED expressed torsional moments of 5-20Nmm from 21-72°, In-Ovation-R from 24-63° and Damon-3MX from 27-78°. / Medical Science-Orthodontics
4

Two and three dimensional cephalometric assessment of dental and skeletal changes following orthodontic treatment with Damon passive self-ligating system

Ehsani, Sayeh 06 1900 (has links)
Objectives: The aim of this study was to evaluate dental and/or skeletal changes following orthodontic treatment with Damon self-ligating (SL) brackets in non-extraction patients. Methods: Frontal and lateral cephalomteric radiographs of 20 patients before and after non-extraction treatment with Damon SL brackets were analyzed in a three-dimensional analysis computer program (3DCeph, UIC, IL., USA). Changes of intermolar and intercanine distances, incisor positions and maxillary basal bone width of Damon treated subjects were compared to corresponding untreated controls (Bolton templates). Comparisons between the two groups were made with Nonparametric (Mann-Whitney U) test. Results and Conclusions: Transverse changes in distances between crowns of upper and lower first molars and canines in Damon group were similar to untreated individuals (P >0.01). However, in Damon group distances between roots of upper molars and lower canines increased 4.59 and 3.49 mm respectively, compared with 0.8 and -0.01 mm in the Control group (P <0.001, P= 0.001). Lingual root torque of upper incisors and proclination of lower incisors were larger in the Damon group (P<0.05). Damon treatment did not result in buccal tipping of molar crowns or maxillary base width increase (P>0.05). Overall, teeth alignment with Damon system was accomplished with a combination of arch width changes and incisor proclination and/or lingual root torque.
5

Two and three dimensional cephalometric assessment of dental and skeletal changes following orthodontic treatment with Damon passive self-ligating system

Ehsani, Sayeh Unknown Date
No description available.
6

Buccal Bone Changes With Self Ligating Brackets Versus Conventional Brackets. A Comparative Study

Kortam, Sahira Ibrahim 23 August 2010 (has links)
No description available.
7

Dimensional Slot Integrity and Precision of Self-Ligating Buccal Tubes

Cohen, Yonatan January 2015 (has links)
Self-ligating brackets, including molar buccal tubes, have gained popularity in recent decades. The primary advantage of using self-ligating systems has been based on the claim that they provide reduced friction and therefore reduced sliding resistance of the arch wire contained within their respective slots.1 This form of reduced friction and sliding resistance has been proposed to require less force and therefore produce more physiologic tooth movements.7-9 Limited scientific evidence is currently available to establish quality control of these products. The purpose of this study is to use Micro Computed Tomography (MicroCT) to analyze self-ligating molar tubes manufactured by different companies. Methods used here provide a novel way for measuring the accuracy and quality of these materials. This study has provided a highly innovative approach that had not been previously accomplished. Forty self-ligating lower left first mandibular molar samples were obtained from four different companies. Five samples from each company were randomly selected and scanned using MicroCT to determine the internal slot lumen of each tube for analysis of precision volumetric measurements. Additionally, qualitative analysis of the lumen of each tube was investigated for the presence of any internal slot defects or imperfections. Results showed that the volumetric slot measurements of all samples were highly statistically significant (P&lt;0.001) and were found to be oversized compared to what is claimed by their respective companies. Qualitative analysis of all samples illustrated varying defects contained within their respective internal slot lumens. Notable defects included notched, beveled and irregular corners, as well as the presence of some bulbous metal projections. Based upon the results obtained in this study, it was determined that the investigated self-ligating buccal tubes, produced by all the companies tested, were oversized and had various internal slot defects. The potential clinical significance of these dimensional inaccuracies may include an increased amount of friction and a lack of torque control during tooth movement. / Oral Biology
8

Análise fotoelástica das tensões produzidas por arcos ortodônticos expandidos associados aos bráquetes autoligáveis e convencionais / Photoelastic analysis of tensions produced by expanded orthodontic arches associated with self-ligating and conventional brackets

Silva, Helena Cristina Francisco Pereira da 02 May 2018 (has links)
O objetivo desta pesquisa foi avaliar as áreas de tensões produzidas por arcos ortodônticos expandidos associados a diferentes tipos de bráquetes durante a fase de alinhamento e nivelamento ortodôntico. A partir de modelos de gesso adquiridos durante a fase de nivelamento ortodôntico do arco dentário inferior de um mesmo paciente, obteve-se 3 modelos fotoelásticos que receberam 3 diferentes tipos de bráquetes: convencional (Ovation®, GAC International, New York, EUA), autoligável ativo (In-Ovation®, GAC International, New York, EUA) e autoligável passivo (Damom 3MX®, Ormco, Califórnia, EUA), associados a arcos de liga de níquel-titânio 0.014\" e 0.014\" x 0.025\" e de liga de aço 0.019\" x 0.025\". Os modelos fotoelásticos com os respectivos arcos e bráquetes ortodônticos foram observados em polariscópio circular, e as imagens fotográficas das regiões dos incisivos, pré-molares e molares foram analisadas qualitativa e quantitativamente. A análise qualitativa foi realizada pela identificação da ordem e coloração das franjas nos locais onde ocorreram, e a quantitativa foi realizada utilizando o software Matlab® para a identificação dos padrões de cores RGB nas áreas dos terços médio-apicais dos dentes de cada região. Os dados obtidos das diferentes associações arcos/bráquetes ortodônticos foram comparados estatisticamente pelo teste de Wilcoxon. Pode-se concluir que, na região dos incisivos, as maiores tensões ocorreram quando os arcos ortodônticos foram associados aos bráquetes autoligados passivos. Na região dos pré-molares, as maiores tensões ocorreram quando o arco 0.014\" foi associado ao bráquete convencional, em movimentos de segunda ordem (extrusão) e de angulação, e quando os arcos retangulares foram associados aos bráquetes autoligados passivos. Na região dos molares, as maiores tensões ocorreram quando os arcos retangulares foram associados aos tubos ortodônticos com maior prescrição de inclinação (Ovation® e In-Ovation®). / The aim of this research was to evaluate the areas of tension produced by expanded orthodontic arches associated with different types of brackets during the orthodontic leveling phase. From plaster models of a single patient lower dental arch obtained during the orthodontic alignment and leveling phase, three photoelastic models were developed that received three different types of brackets: convencional (Ovation®, GAC International, New York, EUA); active self ligation bracktes (In-Ovation®, GAC International, New York, EUA) e passive self ligation bracktes (Damom 3MX®, Ormco, Califórnia, EUA), associated with 0.014\" and 0.014\" ? 0.025\" titanium-nickel alloy arches and 0.019\" ? 0.025\" alloy steel arches. These models were analyzed in a circular polariscope; photographic images of the incisor, premolar, and molar regions were qualitatively and quantitatively analyzed. The first analysis was obtained by identifying the photoelastic fringe order at sites where they occurred, and the second one was obtained using Matlab® software to identify RGB color patterns in middle apical tooth areas of each region. Data from the different orthodontic arches and brackets were compared using the Wilcoxon test. Our results showed that in the incisors region the greatest tensions occurred when the orthodontic arches were associated to the self-ligating passive brackets; in the premolars region, by the association of the 0.014\" arch and conventional bracket in second order (extrusion) and angulation movements and when the rectangular arches were associated with the passive self-ligating brackets. The greatest tensions in the molar regions occurred by association of rectangular arches and inclination high prescriptions orthodontics tubes (Ovation® and In-Ovation®).
9

Alterações das dimensões dos arcos dentários e das inclinações dos incisivos produzidas pelo Sistema Damon / Arch width and incisor torque changes produced by the Damon System

Valeria Matos Bezerra 19 December 2012 (has links)
PROPOSIÇÃO: O objetivo deste trabalho foi descrever as alterações das dimensões dos arcos dentários e das inclinações dos incisivos produzidas pelo Sistema Damon, durante a fase de alinhamento e nivelamento. Outro objetivo foi verificar a correlação destas alterações com o padrão de crescimento dos indivíduos. MATERIAL E MÉTODOS: modelos de estudo, telerradiografias convencionais e telerradiografias reconstruídas a partir de tomografias computadorizadas cone-beam de 22 casos tratados com o bráquetes Damon 3MXTM foram avaliados durante a fase de alinhamento e nivelamento. Os modelos de estudo foram obtidos ao início do tratamento (T0), após a primeira troca de fio (T1) e na inserção do fio de aço 0,019 x 0,025 (T2). Foram verificados os comprimentos de arco e as dimensões transversais nas regiões de caninos, primeiros e segundos pré-molares e primeiros molares mensuradas a partir das pontas de cúspides e margens gengivais linguais dos dentes, a cada etapa. Nas telerradiografias foram verificadas as alterações das inclinações dos incisivos inferiores e superiores, bem como o padrão de crescimento dos indivíduos. RESULTADOS: os comprimentos dos arcos e todas as distâncias transversais apresentaram aumentos significantes, com exceção da distância intercervical dos caninos superiores; houve aumento significante das inclinações vestibulares dos incisivos superiores e inferiores; o padrão de crescimento dos pacientes apresentou correlação significante com os aumentos transversais na região de pré-molares inferiores. CONCLUSÕES: o alinhamento e nivelamento de casos tratados sem extrações com o uso do Sistema Damon resultou no aumento significante das dimensões dos arcos dentários e das inclinações dos incisivos para vestibular. / OBJECTIVE: This study aimed to evaluate the dental arch widths and incisor torque changes produced by the Damon System during leveling and alignment. Other objective was to verify the correlation between these changes and the growth pattern. MATHERIAL AND METHODS: study casts and lateral radiographs derived from cone-beam computed tomographies of 22 subjects treated with Damon 3MXTM brackets were evaluated. The study casts were obtained at the start of treatment (T0), the first archwire change (T1), and the placement of the final 0,019 x 0,025-in archwire (T2). Arch depth and widths (intercanine, interpremolar and intermolar) were assessed at each stage. The incisor torques changes and the growth pattern were measured on the cephalometric records at T0 and T2. RESULTS: There was significant increase of the arch depths and lateral expansion of the arches for all measures, except for the intercervical of maxillary canines. The maxillary and mandibular incisors were significantly tipped labially; the growth pattern showed significant correlation with the lateral increases in lower premolars region. CONCLUSIONS: nonextraction cases treated with Damon System show significant increases in arch dimensions and incisors proclination.
10

Avaliação da profundidade da canaleta dos bráquetes autoligados passivos associados à expressão do torque / Evaluation of the slot depth of passive self-ligating brackets associated with torque expression

Saraiva, Patrick Cavallini 24 March 2017 (has links)
Um dos fatores responsáveis para o sucesso do tratamento ortodôntico é o controle do movimento dentário nos três planos do espaço. Nos bráquetes autoligados e pré-ajustados, a inclinação dos dentes no sentido vestíbulo-lingual depende diretamente da interação bráquete/ fio. Sabendo-se da importância do controle do torque, o propósito deste estudo foi definir a folga entre bráquetes/ fio, avaliar o momento de torque, e correlacionar estes valores nos bráquetes autoligados passivos com profundidades de canaletas diferentes (Damon Q e H4). Para esta pesquisa foi confeccionado um dispositivo experimental em conjunto com uma máquina de testes universal (Model 5565, Instron, Canton, Mass) para medir a expressão do torque nos bráquetes ortodônticos. Para verificar se a difereça na profundidade das canaletas dos bráquetes interferiram na expressão do torque, foram realizadas análises de variância (ANOVA), e teste de Tukey (p<0,05) para identificar as diferenças entre os grupos. Os bráquetes H4 apresentaram maior folga entre bráquete/ fio, quando comparados aos bráquetes Damon Q. Ao avaliarmos o momento de força da expressão do torque, os bráquetes H4 e Damon Q apresentaram diferenças estatisticamente significantes apenas com 24º e 36º de torção. Após a análise dos resultados, ao comparar os valores da expressão de torque com 12º, 24º e 36º, observamos maior expressão de torque no bráquete Damon Q quando comparado ao bráquete H4; Observamos também que o Damon Q expressa melhor o torque quando comparado com o H4, com momentos de força de 5 Nmm, 10 Nmm, 15 Nmm e 20 Nmm. / One of the factors responsible for the success of orthodontic treatment is the control of tooth movement in the three planes of space. In self-ligating and pré-adjusted brackets, the labio-lingual inclination of the teeth depends directly the bracket / wire interaction. Knowing the importance of torque control, the purpose of this study was to define the play between the brackets and wires, to evaluate the moment of torque, and to compare these values in passive self-ligating brackets with different slot depths (Damon Q and H4). For this research, an experimental device was designed in conjunction with a universal test machine (Model 5565, Instron, Canton, Mass) to measure the torque expression in orthodontic brackets. To verify if the differences in the depth of the bracket slots interfered in the torque expression, analyzes of variance (ANOVA) and Tukey test (p <0.05) were performed to identify the differences between the groups. The H4 bracket had the highest play when compared to the Damon Q bracket. When evaluating the moment of torque expression, bracket H4 and Damon Q presented statistically significant differences only with 24º and 36º of torsion. After the analysis of the results, when comparing the values of the torque expression with 12º, 24º, and 36º, we observed greater torque expression in the Damon Q bracket when compared to the bracket H4; we also observed that the Damon Q expressed better the torque when compared with H4, with moments of force of 5 Nmm, 10 Nmm, 15 Nmm, and 20Nmm.

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