Orientadores: Alexandre Elias Trivellato, Marcio de Moraes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-21T07:03:24Z (GMT). No. of bitstreams: 1 Cavalieri-Pereira_Lucas_D.pdf: 1578055 bytes, checksum: 8c7fc995f3dac6a8d0d45c1bc49f3175 (MD5) Previous issue date: 2012 / Resumo: Fraturas do ângulo mandibular são muito freqüentes 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, empregando-se a técnica de Champy. Foram utilizadas 63 mandíbulas dentadas, submetidas aa seccionamento simulando uma fratura linear e favorável de ângulo mandibular esquerdo. As fixações foram realizadas com placas retas do sistema 2,0 mm, dispostas da seguinte forma: uma placa com quatro furos, uma com cinco furos e uma com quatro furos e extensão (ponte). A estabilização e fixação foram realizadas com adaptação da placa e quatro parafusos de 6,0 mm de comprimento, sobre a linha oblíqua da mandíbula. Foram elaborados 9 grupos, com 7 mandíbulas cada um, sendo 3 grupos fixados com placa de 5 furos, 3 com placa reta de 4 furos com extensão e 3 com placa reta de 4 furos. Cada conjunto foi submetido ao teste de carregamento linear com aplicação de carga no sentido súpero-inferior em três pontos distintos da mandíbula, de modo não simultâneo (região de molar ipsilateral à secção, incisivos centrais e molar contralateral) em máquina de ensaio universal EMIC DL 2000. Foram mensurados valores de carga no deslocamento de 1 mm, 2 mm e final e anotado o deslocamento final. Os resultados obtidos foram submetidos à análise estatística, utilizando a análise de variância (ANOVA), seguido do teste de Tukey, nível de significância de 5%. Nos valores de cargas obtidos, tanto quando aplicada no molar ipsilateral ao seccionamento, no molar contralateral ao seccionamento e entre incisivos centrais, foi verificada diferença estatística somente no momento do deslocamento final, na qual a placa com 5 furos e com 4 com extensão foi superior a placa com quatro furos. Não houve diferença entre placa com 5 furos e com 4 com extensão / Abstract: 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, using the technique of Champy. Sixty three toothed mandibles were used, subject to sectioning simulating a linear and favorable 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 with 5-holes and one 4-holes and extension (bridge). Stabilization and adjustment were performed with locking plate and four screws of 6.0 mm in length, about the oblique line of the mandible. Nine groups were elaborated, with 7 each, which 3 groups being fixed with 5-holes plates, 3 groups with 4-holes plates with extension and 3 groups with 4-holes plates. 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 final and was noted the final dislocation. The results were submitted to statistical analysis, using analysis of variance (ANOVA) followed by Tukey test, a significance level of 5%. The values obtained, when loads were applied in the ipsilateral molar, contralateral molar and incisors, was verified statistically only at the final dislocation, in which the 5-holes plates and 4-holes with extension was more resistant than 4-holes plates. There was no difference between plate with 5-holes and 4-holes with extension / Doutorado / Cirurgia e Traumatologia Buco-Maxilo-Faciais / Doutor em Clínica Odontológica

Orientadores: Francisco Humberto Nociti Junior, Enilson Antonio Sallum / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:59:16Z (GMT). No. of bitstreams: 1 Menezes_JulianaBezerraSaldanha_D.pdf: 805559 bytes, checksum: eb703f4648ccb1fb4eeab1900b79a4aa (MD5) Previous issue date: 2005 / Resumo: O objetivo do presente estudo foi avaliar a influência do consumo de cigarros sobre as alterações dimensionais que ocorrem no rebordo alveolar após a extração dentária. Foram selecionados 21 pacientes, com extrações indicadas de elementos anteriores na maxila, por causas periodontais, fraturas ou presença de cáries. Cada participante foi designado para um dos seguintes grupos: grupo 1 (n=11)- não fumantes ou grupo 2 (n=10)-pacientes que fumam um mínimo de 10 cigarros/dia. No período máximo até 7 dias após a extração, os participantes foram submetidos a uma tomografia linear, para determinação da altura e da largura do rebordo alveolar, e a uma radiografia periapical, para cada dente extraído, que foi utilizada para determinação da densidade radiográfica. Os parâmetros foram reavaliados com 6 meses após a extração. A análise intragrupos (teste t-pareado) revelou uma redução estatisticamente significante para o parâmetro altura óssea, no grupo dos não-fumantes (P=0,019) e dos fumantes (P<0,001), entretanto quando as médias de altura dos dois grupos foram comparadas entre si, não houve diferença estatística, em nenhum dos tempos avaliados (teste-t). Para os parâmetros de largura média e coronária, apenas o grupo dos fumantes apresentou uma redução significante do início aos 6 meses do experimento. A densidade radiográfica no centro do alvéolo diferiu estatisticamente, no grupo dos fumantes, na análise intragrupo (P=0,011) e intergrupos (P=0,006), na reavaliação. As análises intergrupos, nos dois períodos de avaliação, apresentaram médias de densidade radiográfica do osso íntegro significativamente inferiores, no grupo dos fumantes. Dentro dos limites do presente estudo, pode-se concluir que o consumo de cigarros influencia negativamente o processo de remodelação do rebordo alveolar pós-extração / Abstract: The aim of the present study was to radiographically evaluate the effect of cigarette smoking on dimensional alveolar bone changes following teeth extraction. Twenty-one subjects were included and designated to one of the groups, regarding their smoking status: group 1(n=11)- non-smoking and group 2 (n=10)- smoking. After tooth extraction, linear tomography images and conventional periapical radiographs were taken to evaluate the following parameters: height, width and density of alveolar ridge. The radiographic examinations were repeated after six months. The intragroup analysis (paired t-test) demonstrated statistically significant difference for the bone height in smokers (P<0,001) and non-smokers (P=0,019), although no differences were noted between smokers and non-smokers (P> 0,05). The smoking group experienced a significant loss in bone width, in the middle (P=0,009) and coronary (P<0,001) region of the alveolar ridge, over six months. The radiographic density of the socket area in smokers was statistically lower than in non-smokers, after six months (P=0,006). In addition, smokers experienced a radiographic density loss over six months (P=0,011). The radiographic density in a well-defined area apical to the socket was also statistically significant different between smokers and non-smokers at baseline (P=0,036) and after 6 months (P=0,023). Within the limits of the present study, it was concluded that cigarette smoking may negatively influence the alveolar ridge remodeling after tooth extraction / Doutorado / Periodontia / Doutor em Clínica Odontológica

Abstract Reduction of morbidity in osseous reconstruction of cranio-maxillofacial bony defects could come from development of less invasive bone graft harvesting techniques or by elimination of bone graft donor sites using a bone graft substitute. This work studies outcomes and morbidity associated with these two approaches. A power-driven trephine was used to harvest bone from the anterior iliac crest using a minimally invasive surgical technique. Initially the safety of the technique was evaluated in a cadaver model. Twenty-five freshly preserved adult cadavers had a total of 250 cancellous cores of bone harvested from 50 anterior iliac crest sites. Twenty intentional perforations were made to the maximum depth possible with the instrumentation tested. No encroachment upon the peritoneum was found. A total of 84 patients had 333 cores of cancellous bone harvested using the same approach with a complication rate of 3.6% and a patient satisfaction rate of 98.8%. In a further 76 patients the motorized trephine method was compared to traditional open iliac crest corticocancellous block harvesting. The trephine group ambulated earlier, required fewer days of hospital stay and had significantly lower pain scores than the open iliac crest group. Coral-derived granules were used as a xenograft bone graft substitute to treat bony defects in the cranio-maxillofacial skeletons of 36 patients with 54 sites and followed for 12 to 36 months. The augmentations produced satisfactory results with the following complications noted: overt wound infection 1.8%, wound irritation 3.8% and clinically evident resorption in 9.3% of augmented sites. Coral-derived granules were then used to treat 48 dento-alveolar defects in 21 growing patients with trauma induced tooth-loss in the anterior maxilla and elective ankylosed tooth removal in the posterior maxilla and mandible. Coral granules were significantly more efficacious in reconstructing alveolar defects in the posterior maxilla or mandible (93.5%), than the anterior maxilla (17.6%). The minimally invasive technique using a power driven trephine was successful at reducing morbidity from bone graft harvesting at the anterior iliac crest. Coral-derived granules can be used in selected situations as a bone graft substitute and minimize post surgical morbidity by eliminating the bone graft donor site.

Please read the abstract in die section front of this document. / Dissertation (MChD)--University of Pretoria, 2009. / Oral Pathology and Oral Biology / unrestricted

No description available.

In this thesis a new framework is proposed for obtaining the spongy bone, cortical bone, muscle and adipose tissue from MRI data. The method focuses on the accurate extraction of the edges of the target tissues, which is the main drawback of previous works. In this framework six new methods, as listed in section 1.3, are utilized together for improving the result of the segmentation by detecting the relational position of the tissues, acquiring the best possible contribution from the operator in terms of time and efficiency, forward and backward transfer of the segmented tissues at the seed slice and using the newly proposed Deformable Kernel Fuzzy-C Mean (DKFCM) method for improving the result of segmentation on the edges. This method first limits the searching area for the voxels of the target tissue from the whole data to a small strip around the edges of the target tissue. Then, it applies a very accurate segmentation on the searching area, using a deformable kernel, which is capable of adapting itself with the shape of the edge. Comparing the results of this work with some popular MRI segmentation methods like active contour, watershed, FCM and also some heuristic methods, which are proposed in literature for segmenting the MRI to four tissues, demonstrates the superiority of the proposed method especially on the edges.

Orientador: Sergio de Toledo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T01:47:57Z (GMT). No. of bitstreams: 1 Cruz_GabrielaAlessandrada_M.pdf: 15668447 bytes, checksum: 48a5ee54985687b46e68567ad7b84fbb (MD5) Previous issue date: 2004 / Resumo: Os substitutos ósseos são materiais utilizados em procedimentos periodontais regenerativos como uma alternativa para tratamento de defeitos ósseos. Neste estudo foram avaliados a morfologia, o tamanho e a composição química das seguintes partículas: osso bovino orgânico cortical e esponjoso com partículas microgranular medindo entre 0,25 e 1,0 mm e macrogranular medindo entre 1,0 e 2,0 mm, osso bovino cortical inorgânico com partículas medindo entre 0,25 e 1,0 mm, hidroxiapatita com partículas medindo entre 0,75 e 1,0 mm e osso humano descalcificado, congelado e seco medindo entre 0,25 a 0,5 mm. Para a analise da morfologia e do tamanho das partículas, as amostras foram preparadas em portaespécime, metalizadas em ouro e analisadas a vácuo em microscópio eletrônico de varredura (SEM). Para a análise da composição química, as partículas não foram metalizadas e foram analisadas por microanálise de raio X, por espectroscopia por dispersão de energia (EDS). A análise visual realizada por SEM, demonstrou que as partículas de osso bovino orgânico e inorgânico, osso humano e hidroxiapatita apresentaram formato irregular e tamanho variável, maior do que o mencionado no rótulo pelo fabricante. A análise da composição química realizada por microanálise (EDS) detectou a presença de elementos como: sódio, cálcio e fósforo, que são comuns à composição do tecido ósseo, porém revelaram a presença de elementos químicos nas partículas de osso bovino orgânico. Esses resultados sugerem que o osso bovino orgânico não é composto puramente por colágeno e proteína / Abstract: This article evaluates the morphologic and chemical composition of the following bone substitutes: cancellous and cortical organic bovine bone with micro and macro particles size ranging from 0,25 to 1,0 mm and 1,0 to 2,0 mm respectively, inorganic bovine bone with particles size ranging from 0,25 to 1,0 mm, hydroxyapatite with particles size ranging from 0,75 to 1,0 mm and demineralized freeze-dried bone allograft with particles size raging from 0,25 to 0,5 mm. The samples were coated with gold in an ion coater, the morphology was observed and the measurements of particle size were performed on vacuum condition by scanning electron microscopy (SEM). The chemical composition was evaluated by microanalysis EDS using samples without covering. The SEM analyses provided visual evidence that all materials analyzed have irregular shape and the particle size values were larger than the values mentioned by the manufacturer. The microanalysis EDS detected the presence of sodium, calcium and phosphorus that are common elements of the bone tissue. However, mineral elements were detected in all analyzed particles of organic bovine bone excepting for macro cancellous organic bovine bone. These results suggest that the evaluated organic bovine bone could not be considered a pure organic material / Mestrado / Periodontia / Mestre em Clínica Odontológica

Orientador: Cecília Amélia de Carvalho Zavaglia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-26T18:15:17Z (GMT). No. of bitstreams: 1 Pinto_StellaAparecidadeAndrade_M.pdf: 4585027 bytes, checksum: 9494a15673ef4d78415628bf5329a159 (MD5) Previous issue date: 2015 / Resumo: A engenharia de tecidos é um conceito no tratamento de doenças e ferimentos. Tal área engloba o uso de tecnologias da biologia molecular e celular, combinando as vantagens da ciência dos materiais e processamento com a finalidade de produzir a regeneração de tecidos em situações onde a evolução tenha determinado que as células não tenham a capacidade regenerativa ao longo do tempo. A essência da engenharia de tecidos é que todas as células sejam viáveis e a capacidade de iniciação, sustentação e processo de regeneração estão diretamente ligados através de fatores de crescimento ou genes de modo que elas produzam um novo tecido de variedade requerida. Isto pode ser alcançado com a ajuda de um scaffold (matriz de forma geométrica guiada) ou uma arquitetura de um novo tecido, permitindo personalizar um lugar básico sobre um ferimento em um paciente isolado ou em escala industrial maior, nos quais o tecido resultante pode ser reimplantado sobre o paciente. Este trabalho de pesquisa científica teve como objetivo desenvolver malhas poliméricas de PCL com 'beta'-TCP obtidas através do processo de rotofiação. Para tal foram desenvolvidas 3 amostras para estudo: AMOSTRA 1 - malha rotofiada de PCL (controle), AMOSTRA 2 - malha rotofiada de PCL com 'beta'-TCP 5% e AMOSTRA 3 - malha rotofiada de PCL com 'beta'-TCP 10%, sendo que as referidas amostras foram também imersas em solução de Kokubo (fluído corpóreo simulado). As características físico-químicas e estruturais da cerâmica 'beta'-TCP foram avaliadas através de ensaios de difração de RX (DRX), granulometria e microscopia eletrônica de varredura (MEV), enquanto as malhas compósitas obtidas neste estudo foram caracterizadas por microscopia óptica (MO) e MEV. Como resultados tivemos a obtenção de malhas poliméricas com biocerâmica 'beta'-TCP que caracterizam-se como materiais promissores para enxertia visando ao reparo ósseo, visto que demonstraram sua bioatividade pela precipitação de apatita em sua superfície após imersão em fluído corpóreo simulado, servindo de base científica para estudos futuros que viabilizem a reconstrução de defeitos ósseos em seres humanos / Abstract: Tissue engineering is a concept in injuries and diseases treatment. It uses biomolecular and celular technologies, combining the materials sciences advantages aiming tissue regeneration in situations that the human evolution had determinated that the cells can't regenerate over time. The essence of tissue engineering is that all cells are viable and it's ability of initiation, sustenance and regeneration process are directly linked through growth factors or genes to produce new tissue of the required variety. This can be achieved with an scaffold or matrix geometrically guided or an architecture of a new personalized tissue in a pacient or a bioreactor in industrial scale, that the new tissue can be reimplanted in the patient. The aim of this study was the development of polymer based scaffolds of PCL with 'beta'-TCP obtained by jet-spinning. Three samples were developed: SAMPLE 1 - scaffold of PCL (control), SAMPLE 2 - scaffold of PCL with 'beta'-TCP 5% and SAMPLE 3 - scaffold of PCL with 'beta'-TCP 10%, wherein the all of them were immersed in Kokubo's solution (simulated body fluid). The physico-chemical and structural characteristics of the ceramic 'beta'-TCP were evaluated by testing x-ray diffraction (DRX), granulometry and scanning electron microscopy (MEV) and the scaffolds of this study were characterized by optical microscopy (MO) and MEV. The results includes polymer based scaffolds with bioceramic 'beta'-TCP that can be considered promising biomaterials to be used as grafting materials focusing in bone healing and have demonstrated their bioactivity by the apatite precipitation in their surface after immersion in simulated body fluid, acting as scientific basis for future studies in reconstruction of osseous defects in humans / Mestrado / Materiais e Processos de Fabricação / Mestra em Engenharia Mecânica

The objective of this research was to evaluate the relationships between greater adiposity and bone development during adolescence. Bone was evaluated from age 11 to 17 years in the Iowa Bone Development Study using peripheral quantitative computed tomography (pQCT). Body composition (fat and lean mass) was estimated by dual energy x-ray absorptiometry (DXA). The first research aim evaluated the associations between greater overall adiposity and subsequent maturation and bone strength in 135 girls and 123 boys. Greater adiposity was defined according to age 8 Body Mass Index (BMI) to categorize participants as overweight (OW) or healthy-weight (HW). Maturation was defined as the age of peak height velocity (PHV). Bone strength was assessed at the radius and tibia (bone strength index, BSI, and strength-strain index, SSI). Differences in bone strength between OW and HW were evaluated with sex-specific multi-level regression models to account for individual growth and correlation between repeated measurements. Analyses were adjusted for centered age (measurement visit age - grand mean age of cohort), change in fat mass, and limb length in Model 1, with additional adjustment for lean mass in Model 2. Analyses were repeated using biological age (visit age - age PHV). BMI was positively associated with age of maturation in girls and boys (p< 0.05). HW versus OW girls had significantly lower BSI and SSI at the radius and tibia (p< 0.05) in Model 1. Results remained significant except for radial BSI in Model 2. HW versus OW boys had significantly lower BSI and SSI (all p< 0.05) at the tibia, but not radius, in Model 1. Significant differences were sustained in Model 2. Analyses were repeated using biological age, which yielded similar results for boys, but reduced parameter estimates were observed in girls, with only tibial SSI significant in Model 2 (p< 0.05). These findings support a stronger role for greater adiposity in the occurrence of earlier maturation and greater bone strength in girls than boys while greater lean mass appeared to play a greater role in boys. The second research aim evaluated associations between abdominal adiposity and bone in 132 girls and 122 boys. Visceral adipose tissue area (VAT, cm2) and subcutaneous adipose tissue area (SAT, cm2) were estimated from DXA scans. Sex-specific analyses evaluated the fat-bone relationship with growth models using biological age as the time variable adjusted for limb length and lean mass. There were no significant associations between bone parameters and VAT or SAT in girls. In boys, greater VAT was associated with lower trabecular bone density (tBMD) and BSI (all p< 0.05) at the tibia, but not radius. Greater VAT and SAT were associated with smaller cortical bone size and thickness (all p< 0.01) at the radius, but not tibia. Analyses limited to overweight participants showed VAT was negatively associated with periosteal circumference at the radius and tibia, cortical bone thickness at the tibia and SSI (all p< 0.05) at the radius in girls. In boys, the results were relatively unchanged for VAT, while SAT was only significantly associated with lower tBMD (p< 0.05) at the tibia. These results suggest the bone-fat relationship may vary depending on adiposity and bone site. The third research aim evaluated the longitudinal association between intramuscular fat and cortical bone at the tibia from age 11 to 17 years in 153 girls and 143 boys. Muscle density (MD) was used to estimate intramuscular fat (IMF). Lower MD indicates greater IMF. The relationships between muscle density and cortical bone parameters were modeled using multi-level regression models adjusted for biological age, limb length and muscle cross-sectional area measured by pQCT. In the adjusted multi-level regression models, MD was positively associated with cortical bone parameters, but only reached statistical significance for BMD, bone mineral content (BMC), bone cross-sectional area, cortical thickness and SSI in girls, while only SSI was significant in boys (all p< 0.05). These results suggest that greater fat content within muscle may be harmful to weight-bearing cortical bone during adolescence. In conclusion, findings from the first aim suggest there are sex- and site-specific differences in the relationship between adiposity and bone during adolescence. Findings from the second and third aims indicate these differences could be explained, in part, by the existence of specific fat depots (abdominal more so than intramuscular fat) that could be harmful to bone and that may be more apparent in boys due to a sex-specific fat distribution pattern that favors accumulation of abdominal rather than peripheral fat.

The structure and ultrastructure of the microvascular bed of fatty bone marrow and the relationships of this vascular bed to endosteal bone surfaces was studied in adult beagles. The vascular volume of fatty bone marrow, as demonstrated by India ink-gelatin perfusion, appears less than the vascular volume of red bone marrow. The capillaries in fatty bone marrow are found between the large fat cells in a loose reticular connective tissue and have a continuous endothelial lining and basal lamina. Capillaries are frequently found adjacent to bone surfaces in these fatty marrow sites, yet are separated from these surfaces by very thin bone-lining cells. The nuclei of bone-lining cells are often found near these capillaries. The association of bone-lining cells to the microvasculature suggests that these cells may play a role in partitioning the extracellular fluids from the bone.