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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.
31

Effects of vibration forces on maxillary expansion and orthodontic tooth movement

Aldosari, Mohammad Abdullah M. January 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Vibration forces (VF) have been shown to alter the formative and resorptive activities of bone. Studies have investigated the use of VF in applications such as the treatment of osteoporosis, bone fracture healing and implant osteointegration with favorable results. In dentistry, orthodontic tooth movement and maxillary suture expansion are common procedures typically requiring prolonged treatment durations with high relapse rates. We hypothesized that local, intermittent VF applications can enhance bone formation during rapid maxillary expansion and accelerate orthodontic tooth movement. Moreover, we also investigated expression of periostin/OSF-2, an adhesion molecule implicated in the formation of bone during maxillary suture expansion. Our results showed that intermittent VF significantly increased bone volume density of the expended palatal bone but limited the amount of palatal expansion and mineral apposition rate at the suture margins. Also, intermittent VF forces did not show statistically significant acceleration of orthodontic tooth movement but significantly enhanced bone volume density of the interradicular bone after tooth movement. Maxillary expansion was also shown to induce the expression of periostin which was proportional to the magnitude of the expansion force with increased bone mineral deposition.
32

The Quantification of Force Distribution of a Vibrational Device for Accelerating Tooth Movement

Akbari, Amin 08 1900 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / One of the most common concern among patients who need orthodontic treatment is treatment duration. The ability to accelerate orthodontic tooth movements would be bene cial to reduce the undesired side-effects of prolonged treatment. Methods have been used in conjugate with common orthodontic appliances to shorten the treatment. One of them is to use vibrational force (VF), which is non-invasive. The VF stimulates bone modeling and remodeling, which is essential to tooth movement. However, commercial devices used in the clinic failed to deliver consistent outcomes. The effects of the VF highly depend on its intensity the tooth receives. There must be a range of stimulation that optimizes the ffeects. The stimulation outside the range either have no effects or creates damages, which adversely affects the orthodontic treatment. Since these devices have generic mouthpiece and teeth are in di erent heights, hence some teeth cannot get force stimulation and others may be overloaded. The current designs also do not have ability to adjust the level of VF intensity that individual tooth needs, as in some cases orthodontists are required to move a tooth faster than others or even slower, which needs the device to be personalized. There- fore, the primary cause of inconsistent clinical outcomes is the inadequate design of the mouthpiece of the current device. The goal of this study is to design a better vibratory device that not only guarantees VF delivery but also enables orthodontists to control the level of VF on the individual tooth, which meets the patient's treat- ment needs. This is a preliminary study to understand the effects of different design parameters affecting the VF distribution on teeth. A nite element model, which consists of human upper and lower jaws in their occlusal positions and a mouthpiece, was created. The VF was from a vibratory source with a peak load of 0.3N and speci ed frequencies (30 and 120 Hz). The element size was determined through a convergence test and the model was validated experimentally. Results showed that the VF distribution among the teeth relies on the material property of the mouthpiece. The distribution is uneven, meaning some teeth bearing much more load than others. This means, with the current device design, teeth would be a ected with di erent level of force stimulation, which results in di erent clinical outcomes consequently. Dynamic load (VF) changes the force distribution on the teeth comparing to the dis- tribution from a static load. Frequency does not affect the peak load. Finally, the study demonstrated that the level of VF stimulation can be adjusted by introducing clearance or interference between the teeth and mouthpiece. It is feasible to control the level of the VF intensity for individual tooth based on treatment requirement.
33

Avaliação microscópica da movimentação dentária induzida em dentes traumatizados : um estudo experimental em ratos /

Pereira, Alex Luiz Pozzobon. January 2008 (has links)
Orientador: Marcos Rogério de Mendonça / Banca: Osmar Aparecido Cuoghi / Banca: Celso Koogi Sonoda / Banca: Marcio Rodrigues de Almeida / Banca: Acácio Fuziy / Resumo: O objetivo deste estudo foi avaliar microscopicamente os eventos biológicos da movimentação dentária induzida, 15 e 30 dias, após a aplicação de um trauma dentoalveolar experimental em molares de ratos. Foram utilizados trinta ratos, divididos em 6 grupos, com 5 animais por grupo: Grupo 1 - Grupo Controle; Grupo 2 - Grupo Movimentação Controle; Grupo 3 - Grupo Traumatismo Controle 1; Grupo 4 - Grupo Traumatismo e Movimentação 1; Grupo 5 - Grupo Traumatismo Controle 2; e Grupo 6 - Grupo Traumatismo e Movimentação 2. Os animais do Grupo Controle foram acompanhados durante todo o experimento. Nos animais do Grupo Movimentação Controle foi instalado um aparelho ortodôntico e após 7 dias submetidos a eutanásia. Os animais do Grupo Traumatismo Controle 1 e 2 receberam um trauma dentoalveolar experimental de 900cN sobre a superfície oclusal do primeiro molar superior direito e após, respectivamente, 22 e 37 dias submetidos a eutanásia. Nos animais do Grupo Traumatismo Movimentação 1 e 2, 15 e 30 dias, respectivamente após a aplicação do trauma dentoalveolar experimental, foi instalado um aparelho ortodôntico e após 7 dias submetidos a eutanásia. Nos Grupos Experimentais, as maiores concentrações das alterações microscópicas estavam presentes na crista óssea alveolar, com alguns pontos de reabsorção óssea, e no terço apical da superfície distal da raiz mesial do primeiro molar superior direito, com a formação de pequenas áreas de reabsorção de superfície (cemento). O trauma dentoalveolar experimental aplicado neste estudo não promoveu alterações microscópicas significantes no periodonto de proteção e sustentação, a ponto de contra-indicar a movimentação dentária induzida desses dentes. / Abstract: The aim of this study was to evaluate microscopically the biological events of induced tooth movement occurring 15 and 30 days after application of an experimental dentoalveolar trauma on rat molars. For such purpose, 30 rats were allocated to 6 groups of 5 animals each: Group 1 - Control group; Group 2 - Movement Control group; Group 3 - 1 Trauma Control group; Group 4 - 1 Trauma/Movement group; Group 5 - 2 Trauma Control group; and Group 6 - 2 Trauma/Movement group. The animals in the Control group were followed up along the whole experiment. The animals in the Movement Control group received an orthodontic appliance and were sacrificed after 7 days. The animals in the 1 and 2 Trauma Control groups were subjected to an experimental dentoalveolar trauma of 900 cN on the occlusal surface of the maxillary right first molar and were sacrificed after 22 and 37 days, respectively. Fifteen and thirty days, respectively, after being subjected to the experimental dentoalveolar trauma, the animals in the 1 and 2 Trauma/Movement groups received an orthodontic appliance and were sacrificed 7 days later. In the experimental groups, the greatest concentration of microscopic alterations occurred on the alveolar bone crest, with some areas of bone resorption and the formation of small areas of surface resorption (cementum) on the apical third of the distal root of the maxillary right first molar. The experimental dentoalveolar trauma applied in this study did not produce significant microscopic alterations on the gingival and periodontal tissues to contraindicate the induced tooth movement of these teeth. / Doutor
34

実験的歯の移動時における圧迫側歯槽骨に生じる背部骨吸収と血管分布 / Rear resorption at the pressure side incident in orthodontic tooth movement

日下部, 豊寿 25 March 1998 (has links)
歯科基礎医学会, 日下部 豊寿 = Toyohisa Kusakabe, 実験的歯の移動時における圧迫側歯槽骨に生じる背部骨吸収と血管分布 = Rear resorption at the pressure side incident in orthodontic tooth movement, 歯科基礎医学会雑誌, 39(6), DEC 1997, pp.623-640 / Hokkaido University (北海道大学) / 博士 / 歯学
35

Experimental studies on effects of orthodontic forces in generation of immune responses : possible roles for immunoregulating molecules in the control of alveolar bone remodeling /

AL-Hashimi, Najat AL-Sayed, January 2004 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.
36

Tooth movement caused by a loop lingual arch wire as measured on two test models of the mandibular dental arch a thesis submitted in partial fulfillment ... in pedodontics ... /

Carlson, George Thomas. January 1973 (has links)
Thesis (M.S.)--University of Michigan, 1973.
37

Response of the periodontal ligament to systemic estradiol elevation or depletion during orthodontic tooth movement a thesis submitted in partial fulfillment ... orthodontics ... /

George, Donald I. January 1987 (has links)
Thesis (M.S.)--University of Michigan, 1987.
38

Tooth movement caused by a loop lingual arch wire as measured on two test models of the mandibular dental arch a thesis submitted in partial fulfillment ... in pedodontics ... /

Carlson, George Thomas. January 1973 (has links)
Thesis (M.S.)--University of Michigan, 1973.
39

A study of the effects of microwave diathermy upon the rate of orthodontic tooth movement in dogs this thesis is submitted as a partial fulfillment ... in orthodontics ... /

Anderson, George S. January 1955 (has links)
Thesis (M.S.)--University of Michigan, 1955.
40

Avaliação histomorfométrica dos efeitos da movimentação dentária induzida sobre molares de ratos submetidos à luxação extrusiva

Verri, Ana Caroline Gonçales [UNESP] 26 August 2015 (has links) (PDF)
Made available in DSpace on 2016-02-05T18:28:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-08-26. Added 1 bitstream(s) on 2016-02-05T18:33:12Z : No. of bitstreams: 1 000857906.pdf: 2103236 bytes, checksum: 2582a030a1fc23bc86e2ad571753944a (MD5) / Introdução: A Ortodontia apresenta grande preocupação com os traumatismos aos tecidos periodontais, pois o sucesso do tratamento ortodôntico depende da integridade destas estruturas. Objetivo: Avaliar os efeitos da movimentação dentária induzida em dentes jovens que sofreram luxação extrusiva em relação aos eventos histopatológicos, entre eles: infiltrado inflamatório, células gigantes multinucleadas e reabsorção radicular. Materiais e Métodos: Sessenta ratos machos Wistar foram divididos em 6 grupos (n=10): Grupo 1 (Controle); Grupo 2 (Traumatismo Controle 5 dias); Grupo 3 (Traumatismo Controle 7 dias); Grupo 4 (Movimentação Controle 7 dias); Grupo 5 (Traumatismo 5 dias e Movimentação 7 dias); Grupo 6 (Traumatismo 7 dias e Movimentação 7 dias). O primeiro molar superior direito foi examinado microscopicamente para determinar os eventos histopatológicos e realizou-se análise histomorfométrica da profundidade da reabsorção radicular. Resultados: Para os grupos tratamentos (G5 e G6) a reabsorção radicular foi evidente nos terços cervical e médio do periodonto mesial da raiz disto-vestibular; infiltrado inflamatório agudo mais intenso; células gigantes multinucleadas próximas às áreas de reabsorção radicular, indicando uma reabsorção radicular inflamatória ativa; septo interradicular menores e não encontrou-se necrose pulpar. Na análise da profundidade das reabsorções radiculares encontrou-se uma baixa ocorrência, não ultrapassando os 50%, sendo que no grupo 6 as reabsorções foram mais profundas em relação aos demais e apresentaram diferença estatisticamente significante em relação aos seus controles (p<0.05). Conclusão: A associação entre movimentação dentária induzida e luxação extrusiva aumenta a ocorrência dos eventos histopatológicos e produz áreas significativamente mais profundas de reabsorções radiculares após 7 dias do trauma (G6) / Introduction: Traumatism in the supporting periodontium is dangerous in the Orthodontic area since orthodontic treatment depends on its integrity. Objective: The aim of this study was to evaluate effects of induced dental movement in teeth that were submitted to extrusive luxation evaluating: inflammatory infiltrated, giant cells and root resorption. Materials and Methods: Sixty Wistar male rats were divided in 6 groups (n=10): Group 1 (Control); Group 2 (Traumatized Control of 5 days); Group 3 (Traumatized Control of 7 days); Group 4 (Movement Control of 7 days); Group 5 (Traumatized of 5 days and Movement of 7 days); Group 6 (Traumatized of 7 days and Movement of 7 days). The upper right first molar was microscopically examined to determine the histopathological events of induced dental movement and histomorphometrical analysis of depth of root resorption. Results: In the experimental groups (5 and 6) the most expressive microscopic alterations were dental root resorption of cervical and medium third of mesial periodontium of distal-buccal root; intense acute inflammatory infiltrated; giant cells near from root resorption areas, showing active root resorption; lower volume of inter root septum and no pulpal necrosis. Analysis of depth of root resorption showed low occurrence that did not exceed 50%. In the group 6 the resorption was deeper compared with other groups and presented statistically significant difference in relation to its controls (P<0.05). Conclusion: Association between induced dental movement and extrusive luxation generates higher levels of histopathological events and resorption areas in the dental root significantly higher 7 days after induced trauma (G6)

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