Made available in DSpace on 2014-06-11T19:31:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-05-06Bitstream added on 2014-06-13T19:20:06Z : No. of bitstreams: 1 ribeirojunior_pd_dr_araca.pdf: 475855 bytes, checksum: 25027ddf9644c9757d0a760d4ed4ca58 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Este estudo avaliou in vitro a influência do tipo de miniplaca (convencional ou locking) e do número de parafusos instalados no segmento ósseo distal e proximal para a promoção da estabilidade óssea e resistência da osteossínteses pelo método Champy, utilizada para o tratamento de fraturas de ângulo mandibular. Sessenta hemi-mandíbulas de poliuretano, com consistência similar ao osso mandibular, foram divididas em 4 grupos (n=15) e seccionadas na região de ângulo mandibular simulando uma fratura. Os segmentos ósseos foram fixados por diferentes tipos de miniplacas usando sistema 2.0- mm e parafusos monocorticais de 2.0 x 6.0mm. Nos grupos 1 e 2, dois parafusos convencionais (G1) ou locking (G2) foram instalados em cada segmento ósseo usando respectivamente miniplacas retas convencionais e locking; Nos grupos 3 e 4, três parafusos convencionais (G3) ou locking (G4) foram instados no segmento ósseo proximal e quatro parafusos convencionais (G3) ou locking (G4) foram instalados no segmento distal, usando uma miniplaca convencional (G3) e locking (G4) de sete furos, reta. As hemi-mandíbulas foram submetidas a um teste de compressão utilizando uma máquina universal de ensaio INSTRON até que houvesse um distanciamento entre os segmentos ósseos de 4 mm, seja no sentido horizontal ou vertical. Os dados registrados foram submetidos à avaliação estatística pelo método ANOVA e teste de Tukey utilizando um nível de significância de 1%. As miniplacas locking ofereceram maior resistência ao teste de compressão do que as miniplacas convencionais (p<0.01). Porém, não existiu diferença entre o uso de miniplacas de 7 ou 4 furos (p>0.01). Apesar de não estatisticamente significante os resultados numéricos sugeriram que as miniplacas locking longas oferecem maior resistência ao teste de compressão que as miniplacas locking curtas. / This study evaluated in vitro the influence of the type of miniplate (conventional or locking) and the number of screws installed in the proximal and distal segments on the stability and resistance of Champy’s osteosynthesis in mandibular angle fractures. Sixty polyurethane hemimandibles with bone-like consistency were randomly assigned to 4 groups (n=15) and sectioned in the mandibular angle region to simulate fracture. The bone segments were fixed by different osteosynthesis methods using 2.0-mm miniplates and 2.0 x 6 mm monocortical screws: Groups 1 and 2- Two conventional (G1) or locking (G2) screws were installed in each bone segment using either a conventional (G1) or a locking (G2) straight miniplate; Groups 3 and 4- Three conventional (G3) or locking (G4) screws were installed in the proximal segment and four conventional (G3) or locking (G4) screws were installed in the distal segment using a either a conventional (G3) or a locking (G4) 7-hole straight miniplate. The hemimandibles were loaded in compressive strength in an Instron machine until a 4-mm displacement occurred between the segments either vertically or horizontally. Data were analyzed statistically by ANOVA and Tukey’s test at 1% significance level. The locking plate/screw systems provided significantly greater resistance to displacement under compressive load than the conventional plate/screw systems (p<0.01). However, no statistically significant difference was found between 7-hole and 4-hole miniplates (p>0.01). In conclusion, the locking miniplates offered more resistance than conventional miniplates and long locking miniplates provided greater (number results) bone stability compared to short ones.

Orientador: Marisa Aparecida Cabrini Gabrielli / Banca: Luis Geraldo Vaz / Banca: Eduardo Hochuli Vieira / Banca: Alexandre Elias Trivelato / Banca: Luciana Asprino / Resumo: Este estudo avaliou a resistência ao deslocamento vertical de seis métodos de fixação interna estáveis utilizados na osteotomia sagital do ramo mandibular (OSRM) no movimento de avanço mandibular com rotação anti-horária. Foram utilizadas sessenta hemimandíbulas sintéticas, divididas em seis grupos de 10 hemimandíbulas, todas fixadas com sistema de fixação 2,0 mm da seguinte forma: Grupo I - 1 miniplaca reta de quatro furos e quatro parafusos monocorticais de 6,0 mm; Grupo II - 1 miniplaca reta de seis furos e seis parafusos monocorticais de 6,0 mm; Grupo III - 2 miniplacas retas de quatro furos e oito parafusos monocorticais de 6,0 mm; Grupo IV - 1 placa grade de oito furos e oito parafusos monocorticais de 6,0 mm; Grupo V - 1 miniplaca reta de quatro furos com quatro parafusos monocorticais de 6,0 mm e um parafuso bicortical 2,0 x 12 mm; Grupo VI - 1 miniplaca reta de quatro furos, locking e quatro parafusos monocorticais de 6,0 mm locking. O teste mecânico foi realizado por meio da aplicação de uma força linear na região entre o primeiro pré-molar e canino, em uma máquina de ensaios mecânicos (EMIC- DL2000) com célula de carga de 10 kilogramas Newton (kN). As cargas para o deslocamento de 1, 3 e 5 mm foram registados em Newton (N) e os dados foram transmitidos para um computador. Os resultados foram avaliados utilizando a análise de variância ANOVA (p <0,001) e teste de Tukey para comparação entre os grupos. O sistema de fixação testado nas três condições de deslocamento m... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This study evaluated the resistance to vertical displacement of six stable fixation methods for the sagittal split ramus osteotomy (SSRO) in the mandibular advancement with counterclockwise rotation. Sixty synthetic hemimandibles were used. They were divided into six groups of 10 hemimandibles, all hemimandibles were fixed with 2.0 mm system as follows: Group I - fixation with a straight four-hole miniplate and four monocortical screws 6.0 mm; Group II - a straight six-hole miniplate and six monocortical screws 6.0 mm; Group III - two straight four-hole miniplates and eight monocortical screws 6.0 mm; Group IV - an eight-hole (grid plate) and eight monocortical screws 6.0 mm; Group V - a four-hole straight miniplate with four monocortical screws 6.0 mm and 2.0 x 12 mm bicortical screw; Group VI - a straight four-hole locking miniplate and four monocortical screws locking 6.0 mm. Biomechanical evaluation was performed by applying a linear force in the region between the canine and first premolar, using a mechanical testing machine (EMIC- DL2000) with loading cell of 10 kN. The loads at 1, 3 and 5 mm of displacement were recorded in N and the data were transmitted from the load cell to a computer. Results were analyzed using the variance analysis ANOVA (p < 0.001) and Tukey post-test for comparison between the groups. For the three displacement conditions fixation with two straight 2.0 mm plates and with the grid plate presented higher load values. / Doutor

Orientador: João Roberto Gonçalves / Resumo: Objetivos: O presente trabalho apresentou como objetivo geral estudar a osteoartrite da articulação têmporo-mandibular (ATM) em pacientes submetidos à cirurgia ortognática de avanço e rotação anti-horária maxilomandibular através de novas técnicas computacionais desenvolvidas para otimização do uso de imagens tridimensionais. Como objetivos específicos, buscou-se: avaliar quantitativamente o grau de deslocamento e remodelação condilar após cirurgia, considerando diferenças entre três grupos (Grupo 1, côndilos de pacientes que sofreram cirurgia de reposicionamento de disco articular simultaneamente à cirurgia ortognática; Grupo 2, côndilos de pacientes que apresentavam deslocamento de disco articular mas não foram submetidos à cirurgia de reposicionamento de disco; Grupo 3, côndilos de pacientes com ATM saudável); investigar a estabilidade do procedimento cirúrgico em longo prazo; identificar possíveis diferenças entre os gêneros quanto à remodelação condilar no período de acompanhamento pós-cirúrgico; estudar potencial associação entre fatores clínicos e cirúrgicos com alterações remodelativas no côndilo mandibular de pacientes que sofreram cirurgia ortognática associada à cirurgia de reposicionamento do disco articular. Materiais e Métodos: Três artigos científicos foram elaborados e utilizados para a avaliação dos propósitos apresentados. Resultados: Em média, após cirurgia ortognática observou-se deslocamento condilar para posterior e medial, além de rotações nos três p... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Objectives: The general purpose of this study was to investigate temporomandibular joint (TMJ) osteoarthritis in patients that underwent counterclockwise maxillomandibular advancement surgery, by using new computational techniques developed for optimizing the use of threedimentional images. The specific goals consisted on: quantitatively assessing post-surgical condylar displacemet and remodeling changes, considering differences among three groups (Group 1, condyles from patients submmitted to disc replacement surgery simultaneoustly with the orthognathic surgery; Group 2, condyles from patients that presented with disc displacement but did not undergo disc replacement surgery; Group 3, condyles from patients with healthy TMJ); investigate long-term stability of the surgical procedure; identify possible gender differences considering condylar remodeling in the follow-up period; identify association between clinical and surgical factors with remodeling changes in the mandibular 21 condyles of patients that underwernt disc replacement surgery simultaneously with the orthognathic surgery. Materials and Methods: Three scientific papers were elaborated and used for assessing the purposes presented. Results: On average, after orthognathic surgery it was observed posterior and medial condylar displacement, besides rotations in the three planes of the space. Downward condylar displacement was noticed in Group 1, whereas it moved upward in the other groups (p ≤ 0.001). The overall sur... (Complete abstract click electronic access below) / Doutor

As fraturas do ângulo mandibular são muito frequentes dentre as fraturas mandibulares e um das formas de tratamento é a utilização de fixação interna com placas e parafusos. Neste estudo o objetivo foi avaliar comparativamente a resistência de três tipos de fixação em réplicas de mandíbula de poliuretano. Foram utilizadas 63 mandíbulas dentadas, submetidas a seccionamento simulando uma fratura linear e desfavorável de ângulo mandibular esquerdo. As fixações foram realizadas com placas do sistema 2,0 mm, dispostas da seguinte forma: uma placa reta de quatro furos, uma placa reta de quatro furos com extensão (ponte) e uma placa 3D 4 furos. Cada grupo (n = 21) foi submetido ao teste de resistência linear com aplicação de carga no sentido súpero-inferior em três pontos distintos da mandíbula, de modo não simultâneo (região do primeiro molar ipsilateral à secção, primeiro molar contralateral e incisivos centrais) em máquina de ensaio universal EMIC DL 2000. Foram mensurados valores de carga no deslocamento de 1 mm, 2 mm e 5mm. Os resultados obtidos foram submetidos à análise estatística, utilizando a análise de variância (ANOVA), nível de significância de 5%. Os valores obtidos, não apresentaram diferença estatisticamente significante entre as placas. Os resultados mostraram que as placas 3D produzem escores similares às placas usadas convencionalmente. Com base nos resultados obtidos, pode-se concluir que os três tipos de fixação se comportam de forma similar. / Mandibular angle fractures are very frequent among the mandibular fractures and a form of treatment is the use of internal fixation with plates and screws. In this study, the objective was to evaluate the resistance of three types of fixation in mandibular replicas of polyurethane. Sixty three toothed mandibles were used, subject to sectioning simulating a linear and unfavorable fracture of left mandibular angle. The fixations were performed with straight plates system 2.0 mm, prepared as follows: one plate with 4-holes, one 4-holes and extension (bridge) and one plate 3D 4-holes .Each set was submitted for loading test with load application towards in three distinct points of the mandible, so do not simultaneously (molar region on the side ipsilateral of section, the central incisors and contralateral molar) in universal testing machine EMIC DL 2000. Load values were measured at offset 1 mm, 2 mm and 5mm and was noted the final dislocation. The results were submitted to statistical analysis, using analysis of variance (ANOVA), a significance level of 5%. the values obtained showed no statistically significant difference between the plates. The results show that the 3D plate can reproduce similar mechanical scores to the plates used conventionally. It can be concluded that the three types of fasteners behaved similarly.

No contexto da herbivoria, a interação inseto-planta é um sistema dinâmico. As plantas apresentam características que influenciam a preferência e o desempenho dos herbívoros, como por exemplo, a variação da dureza e espessura do limbo foliar, de forma dependente à espécie e à idade da estrutura considerada. Por sua vez, os insetos podem responder às barreiras das plantas por mecanismos fisiológicos e comportamentais. Há registro de nove espécies de passifloráceas utilizadas por Heliconius erato phyllis (Fabricius, 1775) para o Rio Grande do Sul. As larvas deste herbívoro, entretanto, alimentam-se preferencialmente de Passiflora misera Humbold, Bonplant & Kunth, que confere maior performance, apesar de apresentar menor quantidade de nutrientes que outras hospedeiras utilizadas (ex. Passiflora suberosa Linnaeus). Desta forma, o desempenho associado ao consumo de uma passiflorácea possivelmente relaciona-se, não só ao conteúdo nutricional desta, mas também aos mecanismos morfológicos e comportamentais envolvidos na alimentação. Neste trabalho, verificamos se a dificuldade em acessar o alimento, imposta pela dureza e espessura das folhas das hospedeiras e pelas limitações estruturais das mandíbulas de H. erato phyllis, reflete ou não alterações na utilização da planta, analisando os danos causados a estas e o comportamento das larvas deste herbívoro. Para tanto P. misera, P. suberosa, Passiflora caerulea Linnaeus, Passiflora edulis Sims e Passiflora alata Dryander foram cultivadas, sendo folhas jovens e velhas dessas passifloráceas caracterizadas quanto à dureza e espessura, tanto do limbo como da nervura central. A freqüência dos danos causados à P. misera, P. suberosa, P. caerulea e P. edulis foi avaliada, em relação à idade da folha e ao longo da ontogênese larval. Quantificou-se, também, o índice de microdureza de Vickers das mandíbulas para larvas criadas em P. misera e P. suberosa. Adicionalmente, o tempo relativo aos comportamentos (repousando, alimentando, deslocando, provando e cortando nervura) foi quantificado nas cinco passifloráceas, tanto em folhas jovens quanto nas velhas. Os dados obtidos evidenciaram a existência de variação expressiva em relação à idade da folha, quanto à dureza e espessura para as espécies de passifloráceas utilizadas pelas larvas de H. erato phyllis. O tipo e a freqüência do dano (corte do limbo, raspagem e corte da nervura central) foram influenciados pela variação desses parâmetros físicos, sendo que a raspagem do limbo ocorreu quando larvas de primeiro ínstar foram criadas em folhas velhas. Houve influência ontogenética no incremento de dureza das mandíbulas, porém não foram detectados indícios de que a planta hospedeira influencie no aumento deste parâmetro nessas estruturas. As larvas empregaram grande parte do tempo em repouso, independente da espécie de hospedeira e, na maioria dos casos, dedicaram mais tempo à alimentação em P. misera. Larvas observadas em P. alata dedicaram mais tempo ao repouso e menos tempo à alimentação realizando de uma a duas refeições com pequena duração, a cada seis horas. Esta discrepância no tempo destinado a todos os comportamentos das larvas em P. alata se deve, provavelmente, a fatores químicos inerentes a esta passiflorácea. Lagartas de primeiro ínstar em folhas velhas de P. suberosa e P. caerulea despenderam maior tempo no deslocamento, demonstrando que a procura por um sítio de alimentação favorável é de fundamental importância para esta fase do desenvolvimento, evidenciando assim que a dureza foliar constitui fator limitante para ínstares iniciais, neste heliconíneo. / The plant-insect interaction is a dynamic system. Variation in plant morphological traits such as hardness and thickness of the leaves can influence preference and performance of herbivores, depending upon the species and age of the plant structure taking into. On the other hand, insects can respond to these barriers through physiological and behavioral mechanisms. Nine species of passion vine are used by Heliconius erato phyllis (Fabricius, 1775) in Rio Grande do Sul State. However, their larvae feed preferentially on Passiflora misera Humbold, Bonplant & Kunth, which provide greater performance, despite having a lower amount of nutrients when compared to other host plants (e.g. Passiflora suberosa Linnaeus). Thus, the performance related to consumption of a particular passion vine possibly relates not only to their nutritional value, but also to morphological and behavioral mechanisms involved on feeding by these butterfly larvae. In this study, we investigate whether the difficulty in accessing food, imposed by the hardness and thickness of host leaves when in association to structural limitations on the mandibles of H. erato phyllis larvae, lead in turn to changes in host plant use. We examined the plant hosts damages and also larval behavior of this herbivore on five cultivated passion vine: P. misera, P. suberosa, Passiflora caerulea Linnaeus, Passiflora edulis Sims and Passiflora alata Dryander. Young and old leaves of these passion vine species were characterized in terms of hardness and thickness for the blade and the midrib. The frequency of differences on damage caused to P. misera, P. suberosa, P. caerulea and P. edulis was evaluated in relation to leaf age throughout larval ontogeny. Vickers hardness index was quantified for mandibles dissected from larvae reared on P. misera and P. suberosa. Additionally, the time spent in different behaviors (resting, feeding, walking, tasting and vein cutting) was quantified for the five passion vine, while feeding on both young and old leaves. The data showed the existence of expressive variation in hardness and thickness according to leaf age for the passion vine species used by H. erato phyllis larvae. The type (cutting blade, scraping and vein cutting) and frequency of damages were influenced by the variation of such leaf parameters. Scraping occurred when first instar were reared on old leaves. There was an ontogenetic influence on mandibular hardness, which increases with larval age. However, there was no evidence that the host plant influences the hardness in these structures throughout ontogeny. Independently of the host tanken into account, larvae employed most of the time resting. In several cases, they devoted more time feeding in P. misera. In P. alata, they spent more time resting and less time feeding, having up to only two meals of short duration each, at every six hours. This discrepancy in time is probably due to the presence of deterrent chemicals present in this passion vine. In old leaves of P. suberosa and P. caerulea, first instar larvae spent more time moving, thus showing that the search for an suitable food site is extremely important for this stage of development. Thus, we demonstrate that leaf hardness is a limiting factor for the early larval instars in this heliconian butterfly.

No description available.

Previous studies have shown growth hormone and therapeutic low intensity pulsed ultrasound can enhance mandibular growth separately. The aim of this study is to evaluate the concomitant effect of both of these applications on mandibular growth in rat. Methods: 24 male Sprague Dawley rats were divided into four groups, 6 in each. Groups 1, 2, 3, and 4 were designated as untreated control, recombinant rat growth hormone, Low Intensity Pulsed Ultrasound, and combination of both groups respectively. After 21 days of daily treatment on mandibular condylar, mandibles from euthanized rats are dissected, and scanned by MicroComputed Tomography to measure the mandibular bone volume, bone surface area, and condylar bone mineral density. Also Real-time Polymerase Chain Reaction was performed on the extracted livers’ C-fos, C-jun, and IGF-1 genes expressions. Results: Groups 2, 3 and 4 showed significant (p<0.05) growth stimulation when compared to the untreated control group. However, there was no statistical significant difference between groups 2, 3 and 4 with regard to bone volume or surface area. Conversely, condylar bone mineral density for group 4 was significantly reduced than groups 1, 2, and 3. Rats’ weights were not significantly different among the treatment groups after the treatment was performed. Additionally, gene expression study showed that the expression of C-jun, in harvested livers for Group 4 was less than that of Group 2 showing fewer side effects. Conclusion: When growth hormone was applied to rats’ mandible together with therapeutic ultrasound, preferential increase in bone volume, and surface area occurred with the expense of condylar bone mineral density and with less potential side effects. / Pharmaceutical Science

Ziel dieser Studie war es, die Unterschiede der Reliabilität der Bewegungskapazität des Unterkiefers bei verschiedenen Untersucher- und Probandengruppen über einen Zeitraum von 3 Monaten mit dem Lineal darzustellen. Die Vermessung wurde bei 85 konsekutiv rekrutierten Probanden (Durchschnittalter: 39,8 ± 17,8 Jahre, 60 % weiblich, 56 mit kraniomandibulärer Dysfunktion) durchgeführt. Die Untersuchergruppe setzte sich aus einer Gruppe unerfahrener Studierender der Zahnmedizin, einer Gruppe von 6 erfahrenen, kalibrierten Zahnärzten und einem weiteren erfahrenen, kalibrierten Zahnarzt zusammen. Die Schneidekantendistanzen bei Mundöffnung, die Frontzahnstufen und die Laterotrusionsbewegungen der Probanden wurden in zwei separaten Sitzungen vermessen. In der ersten Sitzung nahmen alle drei Untersuchergruppen die Vermessungen vor, zum zweiten Zeitpunkt nur ein erfahrener Zahnarzt. Die Reliabilität wurde durch die Intra-Klassen-Korrelation berechnet. Die aktive und passive Schneidekantendistanz, sowie der Overjet und der Overbite wurden mit exzellenter Reliabilität vermessen. Die Laterotrusionsbewegungen zeigten sowohl rechts- als auch linksseitig gute bis exzellente Übereinstimmungen. Bei keiner Untersuchergruppe konnten statistisch signifikante Unterschiede zwischen der gesunden Probandengruppe und der Gruppe mit kraniomandibulären Dysfunktionen festgestellt werden. Die Ergebnisse dieser Arbeit zeigen, dass die Vermessung der Bewegungskapazität des Unterkiefers mit dem Lineal, sowohl untersucher- als auch probandenunabhängig über einen mittellangen Zeitintervall von 3 Monaten, eine reliable Prozedur ist und demzufolge als Grundlage für die Diagnosebildung zuverlässig genutzt werden kann.

Objective: We aim to improve our understanding of sleep physiology by describing the changes in mandibular position during sleep in normal subjects. Methods: We developed a novel method for mapping mandibular position simultaneously in three dimensions (anteroposterior, vertical and lateral) using magneto-resistive sensors strategically placed around 3 different moving joints on an external apparatus attached to the head and mandible. Spherical coordinates derived from these sensors provided information of jaw position in each of the three measurement planes. We assessed changes in jaw position in twelve healthy subjects (6 male, 6 female) aged (mean ± SD) 23 ± 7 years, Body Mass Index 22.5 ± 3.4 kg/m2, and with nasal resistance 3.24 ± 0.67 cmH2O/L/s by recording mandibular position simultaneously with overnight sleep polysomnography. Results: Jaw position was significantly influenced by sleep stage (p<0.001). The transition from wake to light sleep (stage one) was accompanied by significant jaw closure and jaw protrusion (p<0.05). As non-rapid-eye-movement (NREM) sleep deepened from stages 1 through slow wave sleep (SWS), vertical jaw opening (p<0.05) and posterior jaw movement progressively increased (p<0.05). REM sleep was associated with the greatest degree of jaw opening of all sleep stages (p<0.05). Lateral jaw position was not significantly different between sleep stages. Conclusion: This study describes, for the first time, an accurate method of measuring changes in mandibular position during sleep in all three dimensions. The observed changes during sleep in healthy subjects suggest a simultaneous modulation of upper airway muscular tone, which may be important in the understanding of upper airway occlusion in Obstructive Sleep Apnea. / Thesis (Master, Physiology) -- Queen's University, 2008-08-29 14:27:57.726

No description available.