994 resultados para maloclusão de Angle classe I


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O método de migração do tipo Kirchhoff se apresenta na literatura como uma das ferramentas mais importantes de todo o processamento sísmico, servindo de base para a resolução de outros problemas de imageamento, devido ao um menor custo computacional em relação aos métodos que tem por base a solução numérica da equação da onda. No caso da aplicação em três dimensões (3D), mesmo a migração do tipo Kirchhoff torna-se dispendiosa, no que se refere aos requisitos computacionais e até mesmo numéricos para sua efetiva aplicação. Desta maneira, no presente trabalho, objetivando produzir resultados com uma razão sinal/ruído maior e um menor esforço computacional, foi utilizado uma simplificação do meio denominado 2.5D, baseado nos fundamentos teóricos da propagação de feixes gaussianos. Assim, tendo como base o operador integral com feixes gaussianos desenvolvido por Ferreira e Cruz (2009), foi derivado um novo operador integral de superposição de campos paraxiais (feixes gaussianos), o mesmo foi inserido no núcleo do operador integral de migração Kirchhoff convencional em verdadeira amplitude, para a situação 2,5D, definindo desta maneira um novo operador de migração do tipo Kirchhoff para a classe pré-empilhamento em verdadeira amplitude 2.5D (KGB,do inglês Kirchhoff-Gausian-Beam). Posteriormente, tal operador foi particularizado para as configurações de medida afastamento comum (CO, do inglês common offset) e ângulo de reflexão comum (CA, do inglês common angle), ressaltando ainda, que na presente Tese foi também idealizada uma espécie de flexibilização do operador integral de superposição de feixes gaussianos, no que concerne a sua aplicação em mais de um domínio, quais sejam, afastamento comum e fonte comum. Nesta Tese são feitas aplicações de dados sintéticos originados a partir de um modelo anticlinal.

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Pós-graduação em Odontologia Restauradora - ICT

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This study compared the effect of the treatment protocol for correcting Class Il malocclusion using the Herbst appliance followed by full fixed Straigh-wire mechanics, in two populations, one Brazilian and one of North American origin As a untreated control sample the data from the University of Michigan Elementary and Secondary School Growth Study (UMGS) was used. Our sample was composed of 12 males and 12 females, with initial mean age of 12 years 7 months and final mean ages of 15 years and 3 months. The Michigan patients comprised 21 females and 7 males, with an initial mean age of 11 years and 9 months and final mean age of 14 years and 4 months. The control sample was paired in number, sex and age to the treated Michigan sample. ln both treated groups, lateral cephalometric radiographs were obtained before the Herbst appliance was cemented and at the end of the fixed appliance phase, The first comparison involved the Brazil group and the untreated controls, which demonstrated that the association of the Herbst appliance followed by fixed Straight-wire appliances provoked positive effects on the dentofacial complex, improving pre-existing maxillo-mandibular relationships, besides increasing dentoalveolar compensations which contributed to correct the malocclusion. The second comparison, involved the Brazl1ian and North-American patients treated with the same protocol. Although the pre-treatment comparison showed that the two groups were not similar in all aspects, they presented almost identical therapeutic modifications, which indicate that the effect of' treatment was very similar. These results point out that, in Class ll treatment, the combination of Herbst/Straight-wire mechanics produce consistent and systematic effects, correcting or minimizing possible skeletal imbalances

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Aim: to evaluate the association of the long face pattern and the mouth breathing, correlating them with the intraoral characteristics. Methods: the sample was composed of 60 Caucasian Brazilian descendents patients, divided in two groups according to the subjective of their facial pattern. The patients were clinically evaluated to determine their respiratory pattern and the diagnosed of malocclusion. The lateral teleradiographies were drawn in standard to verification facial cephalometric pattern. Chi-Square analysis evaluated the association between subjective facial pattern and type of breathing; facial pattern subjective and cephalometric facial pattern. It was also the chi-square with yates correction to evaluate the associations between subjective facial pattern, type of breathing and posterior cross bite; facial subjective standard, type of breathing and anterior open bite; facial pattern between subjective, type breathing and type of Angle´s malocclusion. Results: it showed that long face pattern (group 1) was associated with mouth breathing habit and facial cephalometric standard. Moreover, the long-face pattern (group 1) presented that mouth breathing was associated with a posterior crossbite and Angle Class II malocclusion. Conclusion: the long face pattern - evaluated with subjective facial analyses - was associated with mouth breathing. The long face pattern and patients with mouth breathing was associated with a posterior crossbite and Class II Angle's malocclusion.

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Pós-graduação em Educação Escolar - FCLAR

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Malocclusion class II-1, is represented by a high prevalence in Brazil, being something common in orthodontic practice. One of the main characteristics of this malocclusion is jaw retrusion, by what many devices of jaw advance are presented in the literature. Being one of them Herbst's device, which is a functional and fixed device created by Emil Herbst (1905) and updated by Hans Pancherz in the decade of 80s.This device is characterized by keeping the jaw advance in a continuous way, while presenting a less active treatment, leading to an immediate aesthetic impact, and the patient cooperation is not required. To improve the anchoring and prevent the collapse of the apparatus was set up last amended version of it by Dr Raveli quoted as Herbst splint. Recent research indicates the use of this device after the peak pubertal growth, creating an appropriate response condylar. The aim of this work is to show the orthodontist a choice of how to use the splint Herbst in Class malocclusions II-1.

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Objectives: natural dentofacial changes and that induced by the Thurow modified extra oral appliance (TMEOA) were evaluated in this prospective study. Methodology: the data consisted of fifteen Class II division 1 children 7 to 10 years old, with anterior open bite and hiperdivergent facial pattern treated with the Thurow appliance and of fifteen Class II division 1 children followed longitudinally from 6 to 12 years of age without treatment (Burlington Growth Centre, Toronto University, Canada). The analyses were based in traditional measurements obtained in lateral cephalometric radiographs scanned with the aid of the software Radiocef Studio®. Radiographs were taken in the beginning and after 1 year of treatment for the treated group and at the 6, 9 and 12 years of age for the control group. Results: the data analysis showed that the TMEOA significantly reduced the SNA, ANB, AOBO, SNPOc SNPM, SGO/NMe, OJ e OB. On the other hand the appliance did not interfere with the SNB e SNPP. The natural growth promoted significant change in the ANB, AOBO, SNPOc, OJ e OB from 6 to 9 years and in the SNB, SNPOc e SGo/NMe from 9 to 12 years. The restriction of the maxillary growth (SNA), reduction of the skeletal discrepancy (ANB) and the reduction of the overjet (OJ) were significant with the treatment considering the natural growth as verified in the control group. Conclusion: the TMEOA corrected the skeletal Class II malocclusion by maxillary restriction, reducing the overjet, closing the anterior open bite and decreasing both the hyper divergent facial pattern and mandible plane inclination.

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The aim of this retrospective study was to evaluate mandibular and maxillary changes induced by the use of Herbst applianceand by natural growth through oblique cephalometric radiographs in children with Class II division 1 malocclusion with mandibular retrusion. A sample of 49 individuals with age ranging from 8 to 10 years old (before growth peak) with Class II division 1, were into two groups: Herbst treated group (n=24) and control group (n=25). Both groups were paired for gender and chronological age. Statistical analysis was performed through Student’s t test. The Herbst appliance promoted the Class II correction in a 7 months period by mesialization of lower permanent first molars and distalization of upper permanent first molars. The Herbst appliance had no influence over the mandibular structure or the mandibular length. It was concluded that early treatment with Herbst appliance corrected the Class II malocclusion by means of dentoalveolar changes.

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This work had aim to present two clinical cases with open bite Class II malocclusion that treated in the phase of the mixed dentition with the modified Thurow appliance and in the permanent dentition with fixed appliance. The dentoskeletal effects of these appliances were carefully analyzed with the aid of metallic implants inserted in both maxilla and mandible. The correction of the malocclusion and the improvement of the skeletal, dental and facial relationship were observed in both cases. The modified Thurow appliance followed by fixed-appliance as a two-phase treatment protocol revealed to be an effective treatment approach for the two young people that initially presented a Class II division 1 malocclusion associated to anterior open bite presented.

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Extraoral appliances represent an alternative for correction of Class II malocclusions. The application of external force leads to tooth movement and influence the growth of the maxillomandibular complex. This article aims to present the removable headgear as an adjuvant in the treatment of Class II division 1 in the mixed dentition.

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The purpose of this study was to evaluate skeletal and dental stability in patients who had temporomandibular joint (TMJ) reconstruction and mandibular counterclockwise advancement using TMJ Concepts total join, prostheses (TMJ Concepts Inc. Ventura, CA) with maxillary osteotomies being performed at the same operation. All patients were operated at Baylor University Medical Center, Dallas TX, USA, by one surgeon (Wolford). Forty-seven females were studied; the average post-surgical follow-up was 40.6 months. Lateral cephalograms were analyzed to estimate surgical and post-surgical changes. During surgery, the occlusal plane angle decreased 14.9 +/- 8.0 degrees. The maxilla moved forward and upward. The posterior nasal spine moved downward and forward. The mandible advanced 7.9 +/- 3.5 mm at the lower incisor tips, 12.4 +/- 5.4 mm at Point B, 17.3 +/- 7.0 mm at menton, 18.4 +/- 8.5 mm at pogonion, and 11.0 +/- 5.3 mm at gonion. Vertically, the lower incisors moved upward -2.9 +/- 4.0 mm. At the longest follow-up post surgery, the maxilla showed minor horizontal changes while all mandibular measurements remained stable. TMJ reconstruction and mandibular advancement with TMJ Concepts total joint prosthesis in conjunction with maxillary osteotomies for counter-clockwise rotation of the rnaxillo-mandibular complex was a stable procedure for these patients at the longest follow-up.

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Be stars possess gaseous circumstellar disks that modify in many ways the spectrum of the central B star. Furthermore, they exhibit variability at several timescales and for a large number of observables. Putting the pieces together of this dynamical behavior is not an easy task and requires a detailed understanding of the physical processes that control the temporal evolution of the observables. There is an increasing body of evidence that suggests that Be disks are well described by standard alpha-disk theory. This paper is the first of a series that aims at studying the possibility of inferring several disk and stellar parameters through the follow-up of various observables. Here we study the temporal evolution of the disk density for different dynamical scenarios, including the disk buildup as a result of a long and steady mass injection from the star, the disk dissipation that occurs after mass injection is turned off, as well as scenarios in which active periods are followed by periods of quiescence. For those scenarios, we investigate the temporal evolution of continuum photometric observables using a three-dimensional non-LTE radiative transfer code. We show that light curves for different wavelengths are specific of a mass loss history, inclination angle, and alpha viscosity parameter. The diagnostic potential of those light curves is also discussed.

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Context. Spectrally resolved long-baseline optical/IR interferometry of rotating stars opens perspectives to investigate their fundamental parameters and the physical mechanisms that govern their interior, photosphere, and circumstellar envelope structures. Aims. Based on the signatures of stellar rotation on observed interferometric wavelength-differential phases, we aim to measure angular diameters, rotation velocities, and orientation of stellar rotation axes. Methods. We used the AMBER focal instrument at ESO-VLTI in its high-spectral resolution mode to record interferometric data on the fast rotator Achernar. Differential phases centered on the hydrogen Br gamma line (K band) were obtained during four almost consecutive nights with a continuous Earth-rotation synthesis during similar to 5h/night, corresponding to similar to 60 degrees position angle coverage per baseline. These observations were interpreted with our numerical code dedicated to long-baseline interferometry of rotating stars. Results. By fitting our model to Achernar's differential phases from AMBER, we could measure its equatorial radius R-eq = 11.6 +/- 0.3 R-circle dot, equatorial rotation velocity V-eq = 298 +/- 9 km s(-1), rotation axis inclination angle i = 101.5 +/- 5.2 degrees, and rotation axis position angle (from North to East) PA(rot) = 34.9 +/- 1.6 degrees. From these parameters and the stellar distance, the equatorial angular diameter circle divide(eq) of Achernar is found to be 2.45 +/- 0.09 mas, which is compatible with previous values derived from the commonly used visibility amplitude. In particular, circle divide(eq) and PA(rot) measured in this work with VLTI/AMBER are compatible with the values previously obtained with VLTI/VINCI. Conclusions. The present paper, based on real data, demonstrates the super-resolution potential of differential interferometry for measuring sizes, rotation velocities, and orientation of rotating stars in cases where visibility amplitudes are unavailable and/or when the star is partially or poorly resolved. In particular, we showed that differential phases allow the measurement of sizes up to similar to 4 times smaller than the diffraction-limited angular resolution of the interferometer.

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Composites formed of a polymer-embedded layer of sub-10 nm gold nanoclusters were fabricated by very low energy (49 eV) gold ion implantation into polymethylmethacrylate. We used small angle x-ray scattering to investigate the structural properties of these metal-polymer composite layers that were fabricated at three different ion doses, both in their original form (as-implanted) and after annealing for 6 h well above the polymer glass transition temperature (150 degrees C). We show that annealing provides a simple means for modification of the structure of the composite by coarsening mechanisms, and thereby changes its properties. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4720464]

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The aim of this study was to investigate the influence of image resolution manipulation on the photogrammetric measurement of the rearfoot static angle. The study design was that of a reliability study. We evaluated 19 healthy young adults (11 females and 8 males). The photographs were taken at 1536 pixels in the greatest dimension, resized into four different resolutions (1200, 768, 600, 384 pixels) and analyzed by three equally trained examiners on a 96-pixels per inch (ppi) screen. An experienced physiotherapist marked the anatomic landmarks of rearfoot static angles on two occasions within a 1-week interval. Three different examiners had marked angles on digital pictures. The systematic error and the smallest detectable difference were calculated from the angle values between the image resolutions and times of evaluation. Different resolutions were compared by analysis of variance. Inter- and intra-examiner reliability was calculated by intra-class correlation coefficients (ICC). The rearfoot static angles obtained by the examiners in each resolution were not different (P > 0.05); however, the higher the image resolution the better the inter-examiner reliability. The intra-examiner reliability (within a 1-week interval) was considered to be unacceptable for all image resolutions (ICC range: 0.08-0.52). The whole body image of an adult with a minimum size of 768 pixels analyzed on a 96-ppi screen can provide very good inter-examiner reliability for photogrammetric measurements of rearfoot static angles (ICC range: 0.85-0.92), although the intra-examiner reliability within each resolution was not acceptable. Therefore, this method is not a proper tool for follow-up evaluations of patients within a therapeutic protocol.