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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.
251

Age estimation in the living : a test of 6 radiographic methods

Hackman, S. Lucina M. R. January 2012 (has links)
There is a growing recognition that there is a requirement for methods of age estimation of the living to be rigorously tested to ensure that they are accurate, reliable and valid for use in forensic and humanitarian age estimation. The necessity for accurate and reliable methods of age estimation are driven both by humanitarian, political and judicial need. Age estimation methods commonly in use today are based on the application of reference standards, known as atlases, which were developed using data collected from children who participated in longitudinal studies in the early to mid-1900s. The standards were originally developed to provide a baseline to which radiographs could be compared in order to assess the child’s stage of skeletal development in relation to their chronological age, a purpose for which they are still utilised in the medical community. These atlases provide a testable link between skeletal age and chronological age which has been recognised by forensic practitioners who have essentially hijacked this medical capability and applied it to their fields. This has resulted in an increased use of these standards as a method of predicting the chronological age from the skeletal age of a child when the former is unknown. This novel use of the atlases on populations who are distinct, ethnically, temporally and geographically, from those whose data was gathered and was used in the design of the standard leaves the forensic outcomes vulnerable to challenge in court. This study aims to examine the reliability and accuracy of these standards in relation to a modern population, providing a sound statistical base for the use of these standards for forensic purposes. Radiographs were collected from the local hospital from children who had been X-rayed for investigation during attendance at the local A&E department. Four body areas were selected for investigation; the hand-wrist, the elbow, the knee and the foot-ankle and tests were undertaken to assess the radiographs using six commonly uses methods of age estimation. Further images of the wrist and elbow were collected from children in New Delhi, India. These images were subject to age estimation utilising the methods described.
252

Estudo das propriedades físicas e mecânicas de materiais restauradores odontológicos submetidos a condições de inumação e afogamento para fins periciais / Study of physical and mechanical properties of dental restorative materials subjected to conditions of inhumation and drowning for forensic purposes

Vicente, Sergio Augusto de Freitas 12 January 2015 (has links)
O objetivo deste estudo foi avaliar o efeito da simulação de condições de inumação e afogamento sobre estabilidade de cor, rugosidade de superfície e microdureza de resina composta (RC), cimento de ionômero de vidro (CIV) e amálgama de prata (AM), visando fornecer elementos para diferenciação de materiais estéticos e estimativa do tempo de submissão aos agentes. Foram obtidos 60 incisivos bovinos, que receberam preparos cavitários (6 x 6 mm e 2 mm de profundidade) e foram restaurados com RC FiltekMR Z250 XT (3M ESPE®), CIV KetacTM Fil Plus (3M ESPE®) e AM em cápsulas gs-80 (SDI®). Realizaram-se as primeiras leituras, que se constituíram no baseline, de: cor, (Espectrofotômetro VITA® Easyshade), rugosidade de superfície (Rugosímetro Mitutoyo® Surftest SJ-201P) e microdureza Knoop (microdurômetro Shimadzu® Micro Hardness Tester HMV-2). Em seguida, as amostras foram separadas em dois grupos de 30 (n=10), de acordo com as condições a que foram submetidas: simulação de condições de inumação e de afogamento, por 1, 3 e 6 meses, após os quais novas leituras foram realizadas. Os valores de alteração de cor (&Delta;E, &Delta;L, &Delta;a e &Delta;b) e demais propriedades dos materiais estéticos foram submetidos a análise estatística 3-way ANOVA, medidas repetidas, Bonferroni (p<0,05). Para o amálgama, foram comparados rugosidade superficial e microdureza (2-way ANOVA, medidas repetidas, Bonferroni, p<0,05). Verificou-se que condições de inumação e de afogamento produzem alteração de cor nos materiais restauradores estéticos, que não é tempo dependente. Não houve diferença (p>0,05) na microdureza dos materiais restauradores estéticos em função dos agentes e tempos testados, apesar de apresentarem diferenças inerentes quanto a essa propriedade. Houve alteração significativa (p<0,05) na microdureza do AM, após 6 meses de afogamento. Quanto à rugosidade de superfície, não houve diferença significante (p>0,05) para nenhum dos materiais, agentes e tempos testados. Concluiu-se que a contribuição desses métodos à identificação humana após inumação ou afogamento só é possível considerando-se a microdureza, sendo auxiliada pela análise da alteração de cor do material. Não é possível predizer o tempo de inumação ou afogamento de um indivíduo apenas com base nos parâmetros estudados / The purpose of this study was to evaluate the effect of simulated drowning and burial conditions on color stability, surface roughness and microhardness of composite resin (RC), glass ionomer cement (CIV) and silver amalgam (AM), aiming to provide elements for differentiation of aesthetic materials and estimation of the time of the agents have been subjected to these conditions. 60 bovine incisors were prepared with a 6 x 6 x 2mm cavity and were restored with RC FiltekMR XT Z250 (3M ESPE®), CIV KetacTM Fil (3M ESPE®) and AM capsules gs-80 (SDI®). The color, surface roughness and microhardness baselines were measured using a reflectance spectrophotometer with CIE L*a*b* system (VITA® Easyshade), a surface roughness device (Mitutoyo® Surftest SJ-201P) and a micro hardness tester (Shimadzu® HMV-2). Then, the samples were separated into two groups of 30 (n=10), in accordance with the conditions that they were subjected: simulation of burial and drowning conditions, for 1, 3 and 6 months, after which further measurements were performed. Values of &Delta;E, &Delta;L, &Delta;a e &Delta;b and the other properties of the aesthetic materials were statistically analyzed using 3-way ANOVA, repeated measures, Bonferroni (p<.05). For the amalgam, only surface roughness and microhardness were compared (2-way ANOVA, repeated measures, Bonferroni, p<.05). It was found that burial and drowning conditions produce color change in the aesthetic restorative materials, which is not time dependent. There was no difference (p>.05) in microhardness of aesthetic restorative materials caused by the agents and times tested, notwithstanding they have inherent differences regarding this property. There was significant change (p<.05) in AM microhardness after 6 months of drowning. Regarding surface roughness, there was no significant difference (p>.05) for any material, agents and times tested. It was concluded that the contribution of these methods to human identification after burial or drowning is only possible considering the hardness, being aided by the analysis of the color change of the material. It is not possible to predict the time of burial or drowning of an individual based solely on the studied parameters
253

Validação de três métodos para estimativa de idade de crianças e adolescentes brasileiros / Validation of three methods for age estimation of Brazilian children and adolescents

Benedicto, Eduardo de Novaes 31 July 2017 (has links)
A estimativa de idade é um importante recurso em Odontologia Legal. Entre as diversas formas de se obter uma estimativa de idade, pesquisadores podem fazê-la por meio da análise do estágio de mineralização dos dentes permanentes. Este tipo de análise, torna possível que uma simples radiografia panorâmica possa fornecer dados relevantes para identificar um indivíduo falecido, por exemplo. Este estudo propõe a validação, análise da acurácia e a construção de fórmulas baseadas nos métodos de Liliequist e Lundberg com a adaptação de Hägg e Matsson (LLH), Haavikko (HKK) e Mornstad et al. (MSW) para a estimativa de idade pelo estágio de mineralização dos dentes permanentes em crianças e adolescentes brasileiros. Para alcançar este resultado, foram selecionadas radiografias panorâmicas de brasileiros em uma amostra contendo 1.009 radiografias (387 do sexo masculino e 622 do sexo feminino) com idade entre 8-15,99 anos. Destas radiografias, foram selecionadas apenas as que cumpriram com todos os requisitos dos critérios de inclusão e exclusão. Após a aplicação das metodologias, os resultados foram inseridos e trabalhados no Programa Excel, Pacote Estatístico STATA 13.0. (StataCorp LP, College Station, Texas, EUA) e MedCalc (Medcalc® Software, Mariakerke, Bélgica) de acordo com as necessidades do estudo. As amostras foram divididas sem distinção quanto ao sexo, com distinção quanto ao sexo, e com distinção quanto ao sexo e idade. A comparação dos métodos foi realizada pela diferença de médias da idade dentária com a idade cronológica (ID-IC). A acurácia foi analisada pela Diferença Absoluta (DA). O teste normalidade de Skewness e Kurtosis foi empregado e, dependendo do resultado, os dados foram submetidos ao Test t de Student, ou ao teste de Wilcoxon, para amostras pareadas. Como resultado das comparações sem qualquer distinção quanto ao sexo, a melhor acurácia foi obtida por LLH (DA = 0,97 e ID-IC = 0,58), HKK (DA = 1,42 e ID-IC = -1,35) e MSW (DA = 2,48 e ID-IC = 3,08). Com distinção quanto ao sexo, os valores para o masculino foram: LLH (DA = 0,91 e ID-IC = -0,45), HKK (DA = 1,80 e ID-IC = -1,75) e MSW (DA = 2,74 e ID-IC = 1,17); e para o feminino LLH (DA = 1,01 e ID-IC = -0,67), HKK (DA = 1,17 e ID-IC = -1,09) e MSW (DA = 2,31 e ID-IC = 0,53). Na comparação com distinção entre sexo e idade houve um predomínio respectivamente da técnica de LLH, seguida de HKK e MSW. As equações de regressão aplicadas na mesma amostra apresentaram em média DA = 0,72 e ID-IC = -0,01. Também, algumas fórmulas de regressão múltipla foram construídas a partir dos dados apresentados para as metodologias de LLH e HKK, exceto para MSW que não forneceu dados suficientes para o software criar equações. Ao final, foi possível concluir que é possível a validação das metodologias apresentadas para a população brasileira e que a metodologia que mais se aproximou da população brasileira foi o método de Liliequist e Lundberg com a adaptação de Hägg e Matsson. / Age estimation is an important resource in Forensic Dentistry. Among several ways to obtain the age estimation, researchers may do it by analyzing the mineralization stage of permanent teeth. This type of analysis allows that a simple panoramic radiograph to provide relevant data to identify a deceased individual, for example. This study proposes the validation, accuracy analysis and construction of formulas based on the methods Liliequist and Lundberg with the adaptation of Hägg and Matsson (LLH), Haavikko (HKK) and Mornstad et al. (MSW) for the estimation of age by the stage of mineralization of permanent teeth in Brazilian children and adolescents. To achieve the results, panoramic radiographs of Brazilians were selected in a sample containing 1009 radiographs (387 males and 622 females) aged 8-15.99 years. Of these radiographs, it was selected only those that fulfilled all the requirements of the inclusion and exclusion criteria. After applying the methodologies, the results were inserted and worked in the Excel Program, Statistical Package STATA 13.0. (StataCorp LP, College Station, Texas, USA) and MedCalc (Medcalc® Software, Mariakerke, Belgium) according to the needs of the study. The samples were divided without splitting sex, with splitting sex and with splitting sex and age. The comparison of methods was performed by the mean differences between dental age and chronological age (DA-CA). Accuracy was analyzed by Absolute Difference (AD). The Skewness e Kurtosis normality test was employed and the Student t test, or the Wilcoxon test, for paired samples was submitted depending on the results. The results of comparisons informed, without any distinction as to sex, the best accuracy was obtained by LLH (AD = 0.97 and DA-CA = 0.58), HKK (AD = 1.42 and DA-CA = -1.35) and MSW (AD = 2.48 and DA-CA = 3.08). With distinction to sex the values for male were: LLH (AD = 0.91 and DA-CA = -0.45), HKK (AD = 1.80 and DA-CA = -1.75) and MSW (AD = 2.74 and DA-CA = 1.17); and for female: LLH (AD = 1.01 and DA-CA = -0.67), HKK (AD = 1.17 and DA-CA = -1.09) and MSW (AD = 2.31 and DA-CA = 0.53). In the comparison with distinction between sex and age, there was a predominance of the LLH technique, followed by HKK and MSW, respectively. The regression equations applied in the same sample presented mean AD = 0.72 and DA-CA = -0.01. In addition, some multiple regression formulae were constructed from the data presented for LLH and HKK methodologies, except for MSW, which did not provide enough data for the software to create equations. At the end, it was possible to conclude that it is possible to validate the methodologies presented in the Brazilian population and the methodology that most approached the Brazilian population was the Liliequist and Lundberg method with the adaptation of Hägg and Matsson.
254

St. Vital cemetery (1879-1885) : an osteological and paleopathological assessment

Swanston, Treena Marie 14 April 2008
In the fall of 1999, human skeletal remains and historic artifacts were discovered on private farmland approximately two kilometres south of the Town of Battleford, Saskatchewan. Document searches and a ground-penetrating radar survey of the property resulted in the discovery that the land was once used as a cemetery for the Catholic Church of St. Vital during the years of 1879 to 1885. Numerous interest groups were brought together in the process of handling this sensitive situation, including the landowners, the Heritage Resource Branch of the Department of Saskatchewan Culture, Youth and Recreation, the Rural Municipality of Battle River, the Roman Catholic Diocese of Prince Albert, and the Battleford Tribal Council. A decision was made to relocate the burials to the current town cemetery. In the meantime, permission was granted for the University of Saskatchewan to play the lead role in the excavation and analysis process. The partial and complete skeletal remains of thirty individuals were recovered, and in addition to a basic osteological analysis of the individuals that included sex determination, age at death and population affinity, a detailed assessment of the pathological conditions was also undertaken. The document and artifact analyses will be the subject of a separate thesis by Colette Hopkins.
255

St. Vital cemetery (1879-1885) : an osteological and paleopathological assessment

Swanston, Treena Marie 14 April 2008 (has links)
In the fall of 1999, human skeletal remains and historic artifacts were discovered on private farmland approximately two kilometres south of the Town of Battleford, Saskatchewan. Document searches and a ground-penetrating radar survey of the property resulted in the discovery that the land was once used as a cemetery for the Catholic Church of St. Vital during the years of 1879 to 1885. Numerous interest groups were brought together in the process of handling this sensitive situation, including the landowners, the Heritage Resource Branch of the Department of Saskatchewan Culture, Youth and Recreation, the Rural Municipality of Battle River, the Roman Catholic Diocese of Prince Albert, and the Battleford Tribal Council. A decision was made to relocate the burials to the current town cemetery. In the meantime, permission was granted for the University of Saskatchewan to play the lead role in the excavation and analysis process. The partial and complete skeletal remains of thirty individuals were recovered, and in addition to a basic osteological analysis of the individuals that included sex determination, age at death and population affinity, a detailed assessment of the pathological conditions was also undertaken. The document and artifact analyses will be the subject of a separate thesis by Colette Hopkins.
256

Morfologia labial de interesse para reconstrução facial forense / Morphology lip of interest for forensic facial reconstruction

Paulo Eduardo Miamoto Dias 01 November 2013 (has links)
A Reconstrução Facial Forense (RFF) é uma área da Antropologia Forense que busca aproximar a aparência de um indivíduo desconhecido por meio de reconstrução dos tecidos moles sobre seu crânio, após seu estudo antropológico. A RFF divulgada nos meios de comunicação visa a um reconhecimento, que pode desencadear um processo de identificação humana. Conhecer as relações entre tecidos duros e moles é essencial para se aumentar a precisão das RFFs. Neste estudo, buscou-se reunir informações antropométricas sobre a boca e suas proporções. Foram constituídas duas amostras a partir de um acervo de tomografias computadorizadas. A amostra 1 (n=327) consistiu em homens (n=127) e mulheres (n=185) entre 11 e 81 anos, divididos em seis faixas etárias e buscou verificar as distâncias lineares delimitadas por pontos anatômicos em tecido mole: altura da zona vermelha da boca, largura da boca, proporção entre os mesmos e possibilidade de se estimar a largura da boca a partir da distância intercanina. A amostra 2 (n=108) consistiu em homens (n=40) e mulheres (n=68) entre 20 e 81 anos, divididos em três faixas etárias e buscou verificar as proporções entre altura da zonas vermelha da boca, largura da boca e distâncias lineares entre pontos craniométricos em tecidos duros. As medições foram feitas com o programa OsiriX e os resultados foram analisados através de através de estatística descritiva para todas as variáveis estudadas, por meio da comparação entre as médias, os desvios padrão e as diferenças entre as médias, com intervalo de confiança de 95% (IC95%) e aceitando nível de significância de 5% (p<0,05). Para a amostra 1, a altura da zona vermelha correspondeu a aproximadamente 26% da largura da boca, em ambos os sexos, com tendência a diminuir ao longo do tempo. A largura da boca aumentou ao longo do tempo em homens e manteve-se estável em mulheres. À distância intercanina se atribuiu o valor médio de 75% da largura da boca, em homens, e 80% da largura da boca em mulheres. Para a amostra 2, à distância entre os pontos infradentale e supramentale se atribuiu em média 55% da altura da zona vermelha para ambos os sexos, e entre os pontos philtrum medium e supradentale, em média 85% da altura da zona vermelha em homens, e 88% da mesma medida em mulheres. À distância entre os forames mentuais, se atribuiu em média 97% da largura da boca em mulheres, e em homens 93% deste valor. A reunião de dados antropométricos da boca para a população brasileira pode contribuir para aumentar a precisão das RFFs e auxiliar a identificação humana. / Forensic Facial Reconstruction (FFR) is an area of Forensic Anthropology that seeks to approximate the appearance of an unknown individual by reconstructing soft tissues over ones skull after an anthropological analysis. The FFR published in the media aims at a recognition, which can trigger a process of human identification. Knowing the relationship between hard and soft tissues is crucial to increase the accuracy of FFRs. In this study, we sought to gather anthropometric information on the mouth and its proportions. Two samples were taken from a collection of CBCT scans. Sample 1 (n=327) consisted of men (n=127) and women (n=185) aged between 11 and 81 years old, divided into six age groups and verified the linear distances defined by anatomical landmarks in soft tissue: vermillion height, mouth width, the proportion between these and the possibility of estimating mouth width from the intercanine distance. Sample 2 (n=108) consisted of men (n=40) and women (n=68) aged between 20 and 81 years old, divided into three age groups, and verified the proportions between the vermilllions of the mouth, mouth width and linear distances marked in bony craniometrical landmarks. The measurements were made in OsiriX software and the results were analyzed by averages, standard deviations and differences between the averages. For sample 1, vermillion height corresponded to approximately 26% of mouth width, in both genders, with a tendency to decrease over time. Mouth width increased over time in men, and kept stable values in women. The intercanine distance corresponded to about 75% of mouth width in men, and 80% of the mouth width in women. For sample 2, the distance between the landmarks infradentale and supramentale and was on average 55% of the vermillion height in both genders, and the distance between the landmarks philtrum medium and supradentale was about 85% of the vermillion height in men and about 88% of the same measure, in women. The distance between the mental foramina was on average 97% of the mouth width in women, and 93% of this distance in men. Gathering anthropometric information on the mouth for the Brazilian population can contribute to increase the accuracy of FFRs and assist human identification.
257

Estimativa da idade cronológica por meio de avaliação radiográfica da mineralização de terceiros molares e altura do ramo da mandíbula / Age determination by means of radiographic evaluation of third molar mineralization and height of the mandibular ramus

Fernando Toledo de Oliveira 23 September 2010 (has links)
A estimativa da idade é um elemento importante na investigação antropológica, sendo uma das fontes preliminares dos dados para estabelecer a identidade de pessoas vivas ou restos mortais desconhecidos. Os métodos mais utilizados para este fim são os baseados no desenvolvimento ósseo e dentário dos indivíduos. Neste sentido, o presente trabalho apresentou como objetivo, estabelecer valores de referência na população brasileira para a estimativa da idade, por meio de dois métodos: a análise da mineralização dos terceiros molares; e a mensuração da altura do ramo mandibular. Para isso, foram escaneadas radiografias (407 panorâmicas e 289 cefalométricas em norma lateral) de pacientes, de 6 a 25 anos de idade, atendidos na Faculdade de Odontologia de Bauru. As imagens radiográficas panorâmicas foram utilizadas para análise da mineralização dos terceiros molares inferiores, através do método proposto por Demirjian, Goldstein e Tanner (1973), e as imagens radiográficas cefalométricas utilizadas para medir a altura do ramo da mandíbula. Os resultados indicam uma forte correlação entre a idade cronológica e ambos os métodos utilizados, proporcionando a elaboração de fórmulas para o cálculo da idade aproximada dos indivíduos na população estuda. Não houve diferença estatisticamente significante para o desenvolvimento dos terceiros molares entre os sexos. Já para a altura do ramo da mandíbula, essa diferença ocorreu entre os 16 e 25 anos de idade. A probabilidade de afirmamos que um indivíduo tem 18 anos ou mais de idade, com base nas duas metodologias proposta neste trabalho, é extremamente alta (>90%). Concluiu-se que ambos os métodos estariam aptos a serem utilizados para estimar a idade na população brasileira, entretanto, pelo fato do Brasil ser um país com extenso território e apresentar uma população bastante miscigenada, novos estudos devem ser realizados, aumentando a amostra dessa população, e permitindo o aprimoramento dos valores aqui informados. / Age determination is an important element in anthropological research, one of the primary sources of data to establish the person living identity or unknown remains. The aim of this paper was to establish reference values in Brazilian population to estimate chronological age by two methods: mineralization of third molars and measurement of the mandible ramus height. Therefore, radiographs from patients between 6 to 25 years, were scanned (407 panoramics and 289 cephalometrics). The patients were from School of Dentistry at Bauru. The panoramic radiographs were used for analysis the mineralization of the mandibular third molars. Moreover, cephalometric radiographs were used to measure the mandibular height. The results indicated a strong correlation between chronological age and both methods, providing the development of formulas for calculating the approximate real age of individuals by radiographs. There was no statistically significant difference for the third molars development between sexes. There was a significant difference between men and women for ramus height of the mandible for the range between 16 and 25 years. The probability of a claim that an individual is 18 years or older, based on the two methodologies proposed in this work was extremely high (>90%). It was concluded that both methods were suitable to be used to estimate the age in Brazilian population. However, as Brazil is a country with vast territory and present a fairly mixed population, it is necessary further studies to confirm the values reported.
258

Estudo das propriedades físicas e mecânicas de materiais restauradores odontológicos submetidos a condições de inumação e afogamento para fins periciais / Study of physical and mechanical properties of dental restorative materials subjected to conditions of inhumation and drowning for forensic purposes

Sergio Augusto de Freitas Vicente 12 January 2015 (has links)
O objetivo deste estudo foi avaliar o efeito da simulação de condições de inumação e afogamento sobre estabilidade de cor, rugosidade de superfície e microdureza de resina composta (RC), cimento de ionômero de vidro (CIV) e amálgama de prata (AM), visando fornecer elementos para diferenciação de materiais estéticos e estimativa do tempo de submissão aos agentes. Foram obtidos 60 incisivos bovinos, que receberam preparos cavitários (6 x 6 mm e 2 mm de profundidade) e foram restaurados com RC FiltekMR Z250 XT (3M ESPE®), CIV KetacTM Fil Plus (3M ESPE®) e AM em cápsulas gs-80 (SDI®). Realizaram-se as primeiras leituras, que se constituíram no baseline, de: cor, (Espectrofotômetro VITA® Easyshade), rugosidade de superfície (Rugosímetro Mitutoyo® Surftest SJ-201P) e microdureza Knoop (microdurômetro Shimadzu® Micro Hardness Tester HMV-2). Em seguida, as amostras foram separadas em dois grupos de 30 (n=10), de acordo com as condições a que foram submetidas: simulação de condições de inumação e de afogamento, por 1, 3 e 6 meses, após os quais novas leituras foram realizadas. Os valores de alteração de cor (&Delta;E, &Delta;L, &Delta;a e &Delta;b) e demais propriedades dos materiais estéticos foram submetidos a análise estatística 3-way ANOVA, medidas repetidas, Bonferroni (p<0,05). Para o amálgama, foram comparados rugosidade superficial e microdureza (2-way ANOVA, medidas repetidas, Bonferroni, p<0,05). Verificou-se que condições de inumação e de afogamento produzem alteração de cor nos materiais restauradores estéticos, que não é tempo dependente. Não houve diferença (p>0,05) na microdureza dos materiais restauradores estéticos em função dos agentes e tempos testados, apesar de apresentarem diferenças inerentes quanto a essa propriedade. Houve alteração significativa (p<0,05) na microdureza do AM, após 6 meses de afogamento. Quanto à rugosidade de superfície, não houve diferença significante (p>0,05) para nenhum dos materiais, agentes e tempos testados. Concluiu-se que a contribuição desses métodos à identificação humana após inumação ou afogamento só é possível considerando-se a microdureza, sendo auxiliada pela análise da alteração de cor do material. Não é possível predizer o tempo de inumação ou afogamento de um indivíduo apenas com base nos parâmetros estudados / The purpose of this study was to evaluate the effect of simulated drowning and burial conditions on color stability, surface roughness and microhardness of composite resin (RC), glass ionomer cement (CIV) and silver amalgam (AM), aiming to provide elements for differentiation of aesthetic materials and estimation of the time of the agents have been subjected to these conditions. 60 bovine incisors were prepared with a 6 x 6 x 2mm cavity and were restored with RC FiltekMR XT Z250 (3M ESPE®), CIV KetacTM Fil (3M ESPE®) and AM capsules gs-80 (SDI®). The color, surface roughness and microhardness baselines were measured using a reflectance spectrophotometer with CIE L*a*b* system (VITA® Easyshade), a surface roughness device (Mitutoyo® Surftest SJ-201P) and a micro hardness tester (Shimadzu® HMV-2). Then, the samples were separated into two groups of 30 (n=10), in accordance with the conditions that they were subjected: simulation of burial and drowning conditions, for 1, 3 and 6 months, after which further measurements were performed. Values of &Delta;E, &Delta;L, &Delta;a e &Delta;b and the other properties of the aesthetic materials were statistically analyzed using 3-way ANOVA, repeated measures, Bonferroni (p<.05). For the amalgam, only surface roughness and microhardness were compared (2-way ANOVA, repeated measures, Bonferroni, p<.05). It was found that burial and drowning conditions produce color change in the aesthetic restorative materials, which is not time dependent. There was no difference (p>.05) in microhardness of aesthetic restorative materials caused by the agents and times tested, notwithstanding they have inherent differences regarding this property. There was significant change (p<.05) in AM microhardness after 6 months of drowning. Regarding surface roughness, there was no significant difference (p>.05) for any material, agents and times tested. It was concluded that the contribution of these methods to human identification after burial or drowning is only possible considering the hardness, being aided by the analysis of the color change of the material. It is not possible to predict the time of burial or drowning of an individual based solely on the studied parameters
259

Análise das propriedades físicas e mecânicas de materiais restauradores odontológicos submetidos à ação do calor e do frio para fins periciais / Analysis of physical and mechanical properties of dental restorative materials subjected to the action of heat and cold for forensic purposes

Roberto Cesar Biancalana 03 June 2015 (has links)
O objetivo deste trabalho foi avaliar o efeito da ação do calor e do frio sobre a estabilidade de cor, rugosidade de superfície e microdureza de restaurações de resina composta (FiltekMR Z250 XT 3M ESPE®), cimento de ionômero de vidro (KetacTM Fil Plus 3M ESPE®) e amálgama de prata em cápsulas (gs-80 SDI®), na tentativa de simular o comportamento desses materiais, quando presentes nos elementos dentais de vítimas carbonizadas ou mortas por congelamento. Foram selecionados 180 dentes bovinos que foram preparados (6 X 6 mm com 2 mm de profundidade) e separados em grupos de 30 dentes, segundo o tipo de material restaurador utilizado. Em seguida, foram realizadas as leituras iniciais de cor (Espectrofotômetro VITA® Easyshade), rugosidade de superfície (Rugosímetro Mitutoyo® Surftest SJ-201P) e microdureza Knoop (Microdurômetro Shimadzu® Micro Hardness Tester HMV-2), que foram consideradas os padrões iniciais. Subsequentemente, os dentes foram separados aleatoriamente em grupos (n=10) segundo a temperatura utilizada para simulação de congelamento (-80°C), (-20°C) e 2,5°C; e carbonização (100°C, 200°C e 300°C). A submissão a altas temperaturas foi realizada pela colocação dos dentes restaurados em forno (ALUMINI Sinter-Press EDG®), pelo período de 15 minutos, e as baixas temperaturas foram realizadas em refrigerador (RFGE 700 GE®) a 2,5°C; congelador (CVU18 Consul®) a (-20°C) e freezer (Ultra Freezer AL 374 - 80V American Lab®) a (-80°C). Após 7 e 30 dias de ação do frio e da submissão ao calor, os dentes foram submetidos às leituras finais de cor, rugosidade e microdureza. No calor, os valores de alteração de cor (&Delta;E*, &Delta;L*, &Delta;a* e &Delta;b*), dos dois materiais estéticos, rugosidade superficial e microdureza dos três materiais restauradores, foram submetidos à análise estatística One-way ANOVA, Tukey (p<0,05), tendo como fator de variação, a temperatura. No frio, os dados foram submetidos à análise estatística 2-way ANOVA, Bonferroni (p<0,05), tendo como fatores de variação, o tempo e a temperatura. Verificou-se que houve alteração de cor dos materiais estéticos, tanto nas submissões ao calor quanto ao frio. Na resina composta, a rugosidade de superfície e a microdureza não se alteraram significantemente (p>0,05), independente da temperatura a que foram submetidos. No CIV, a rugosidade e a microdureza elevaram-se nos testes ao calor; e ao frio, não ocorreram alterações significativas (p>0,05) dessas propriedades. Para o amálgama houve alteração de rugosidade significante (p<0,05) no calor, nas submissões a 300°C; e a microdureza não se modificou. Ao frio não ocorreram mudanças significantes (p>0,05) na rugosidade nem na microdureza do amálgama. Concluiu-se que os materiais estéticos podem ser distinguidos, pela análise de cor, a partir de 200°C até 300°C e quando submetidos a (-80°C), tanto em 7 dias como em 30 dias. O tempo de congelamento não é significativo para a distinção dos materiais. Testes de rugosidade e microdureza podem distinguir os materiais estéticos, independentemente, da ação do calor ou do frio. / The purpose of this study was to evaluate the effect of the action of heat and cold on color stability, surface roughness and microhardness of composite resin (FiltekMR Z250 XT 3M ESPE®), glass ionomer cement (KetacTM Fil Plus 3M ESPE®) and silver amalgam capsules (gs-80 SDI®) restorations, in an attempt to simulate the behavior of these materials when present in dental elements of carbonized or killed by freezing victims. 180 bovine teeth were selected, prepared with a 6 x 6 mm 2 mm cavity and then separated into groups of 30 teeth, according to the type of restorative material. Then, initial color readings (Spectrophotometer VITA® Easyshade), surface roughness (Rugosimeter Mitutoyo® Surftest SJ-201P) and Knoop microhardness (Shimadzu Micro Hardness tester® HMV-2) readings were performed, which were considered the initial standards. Afterwards, the teeth were randomly divided into groups (n=10) according to the temperature used for freezing simulation (-80°C), (-20°C), (2,5°C); and carbonization simulation (100°C, 200°C, 300°C). Submission to high temperatures was performed by placing the restored teeth in an oven (ALUMINI Sinter Press EDG®), for 15 minutes and for low temperatures, a refrigerator (RFGE 700 GE®) at 2,5°C, a freezer (CVU18 Consul®) at (-20°C) and an ultra freezer (Ultra Freezer AL 374 - 80V American Lab®) at (-80°C) were used. After the teeth being submitted to the action of cold and heat for 7 and 30 days, the color, surface roughness and microhardness final readings were performed. For the heat evaluation, the color change (&Delta;E*, &Delta;L*, &Delta;a* e &Delta;b*) of the two aesthetic materials, and the surface roughness and microhardness of the three restorative materials, were subjected to statistical analysis (One-way ANOVA, Tukey, p<.05), with one variation factor, the temperature. For the cold evaluation, the data were statistically analyzed using 2-way ANOVA, Bonferroni, (p>.05) with two variation factors, time and temperature. Color alteration occurred for the aesthetic materials submitted to heat and cold. In the composite resin, the surface roughness and microhardness did not change (p>.05), regardless of temperature to which they were exposed. In CIV, the surface roughness and microhardness increased with the heat. After cold submission, there were no significant changes (p>.05) to these properties. For the amalgam, there was roughness change (p<.05) when submitted to heat at 300°C; the microhardness did not change. There were no significant changes in amalgam roughness or microhardness when teeth were submitted to cold (p>.05). It was concluded that the aesthetic materials can be distinguished by the color analysis, from 200°C to 300°C and when submitted to (-80°C), both after 7 days and 30 days. The freezing time is not significant for the distinction of materials. Roughness and microhardness tests can distinguish the aesthetic materials, regardless of the action of heat or cold.
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Caractérisation de la diagénèse osseuse en anthropologie médico-légale : étude macroscopique, spectrométrique et histomorphologique / Characterization of bone diagenesis in forensic anthropology : a macroscopic, spectrometric and histomorphological study

Delannoy, Yann 15 December 2016 (has links)
Introduction : La détermination du délai postmortem dans les cas de découvertes de restes squelettisés est un élément clé de l’enquête judiciaire. Pour autant, face à la découverte de restes osseux, peu de méthodes sont applicables pour une estimation précise de ce délai. Cette étude taphonomique souhaitait s’inscrire dans une temporalité rejoignant les impératifs judiciaires appliqués en médecine légale. Ainsi, l’hypothèse principale de ce travail était constituée par une dégradation organique précoce de l’os en période postmortem, notamment sous la forme d’une dégradation collagénique. Celle ci a donc fait l’objet d’une évaluation prospective.Matériels et Méthodes : 6 dons de corps humains, sans pathologie osseuse connue ont été inclus et pour chaque sujet, le choix des os étudiés s’est orienté vers les côtes. Ces os ont été inclus dans un environnement de diagénèse et étudiés sur 2 ans. Une analyse macroscopique de perte de poids de l’os a été réalisée, et complétée par deux méthodes : l’une moléculaire (microspectrométrie Raman) et l’autre morphologique (histologie).Résultats : Ce travail, a permis de mettre en évidence certaines caractéristiques de l’altération temporelle des différentes phases osseuses via : une dessiccation mise en évidence par une perte de poids osseuse ; une diagénèse des fractions organiques et minérales. Ainsi, l’étude des paramètres physico-chimiques en microspectrométrie Raman a montré une tendance temporelle à la diminution des rapports phase minérale/phase organique ; la diminution de la carbonatation minérale ; l’augmentation de la cristallinité. L’analyse statistique multivariée des spectres Raman a permis : de distinguer des groupes temporels en les discriminant via leurs contributions organiques ; de construire l’ébauche d’un modèle statistique d’utilisation pratique. L’étude microscopique des prélèvements a montré l’absence de toute attaque microbienne en période postmortem précoce, mais un mécanisme d’altération organique collagénique de type hydrolyse chimique.Discussion : Notre travail, a permis d’identifier 3 paramètres fondamentaux du vieillissement osseux qui doivent être connus du praticien qualifié en anthropologie médico-légale, et cela même sur une période d’étude de 2 ans « courte » à l’échelle de l’anthropologie :- L’environnement influence fortement la diagénèse osseuse et doit être aussi bien étudié que l’os en lui même. En effet, l’étude de la perte de poids de l’os, a montré une altération de composition osseuse très précoce avec phénomène de dessiccation osseuse, comparable à la déshydratation globale du corps en période postmortem ;- La diagénèse osseuse est un phénomène global dans lequel les différentes altérations de phases minérales et organiques sont interdépendantes et peuvent être appréciées par la microspectrométrie Raman, qui outre son apport dans l’analyse de la dégradation chimique de l’os, permet par les outils statistiques qui y sont associés, d’identifier des classes temporelles de diagénèse. Ces classes, qui devront faire l’objet d’études supplémentaires, pourraient à terme être une aide pratique et servir de référence dans la datation précise d’un os ;- L’altération organique de l’os peut s’opérer selon des modes de dégradations chimiques ou bactériens en fonction de l’environnement et du délai postmortem. L’histologie peut permettre de faire ce distinguo. Sur ce délai d’étude, la dégradation collagénique de type chimique par hydrolyse est prédominante.Conclusion : Ces paramètres forment une unité structurelle indissociable qui est connue de longue date en anthropologie archéologique, et qui est parfaitement transposable en pratique médico-légale si des méthodologies adaptées sont développées. Les voies de recherche sur cette thématique ont un rôle essentiel à jouer pour que la médecine légale puisse répondre aux légitimes demandes exprimées par les victimes et leurs ayants-droits auprès de la justice. / Introduction: Determining the postmortem interval in cases of skeletonized remains is a key element of the judicial investigation. However, few methods are applicable for an accurate estimate of this period. This taphonomic study wanted to be performed in a temporality joining the legal requirements applied in forensics. Thus, the main hypothesis of this study was an early organic postmortem bone degradation, particularly a collagen degradation. The latter has been studied prospectively.Materials and Methods: 6 human bodies without known bone disease were included, and for each subject, the ribs were chosen. The bones were included in a diagenetic environment and studied over 2 years. Macroscopic analysis of bone weight loss was performed, and completed by two methods: one molecular (Raman microspectrometry) and the other morphological (histology).Results: This work has highlighted certain features of the temporary bone alteration on its different phases via: a desiccation highlighted by bone mass loss; a diagenesis of organic and mineral phases. Thus, the study of physicochemical parameters by Raman microspectrometry revealed a temporary trend of declining mineral / organic ratios; decreasing carbonation; increasing crystallinity. Multivariate analysis of Raman spectra allowed: to distinguish temporal groups by discriminating via their organic contributions; to design a statistical model of practical use. The microscopic study of the samples revealed no microbial attack in the early postmortem period, but an alteration of collagen by chemical hydrolysis.Discussion: Our study identified three basic parameters of bone diagenesis that must be known to the forensic anthropologist, even over a period of 2 years which is \\\"short\\\" on the scale of anthropology:- The environment strongly influences bone diagenesis and should be studied as well as the bone itself. Indeed, the study of weight loss of the bone, revealed a phenomenon of bone drying, similar to the overall dehydration of the body in the postmortem period;- Bone diagenesis is a global phenomenon in which the various alterations of inorganic and organic phases are interdependent and can be evaluated by Raman microspectrometry. Also its contribution in the analysis of the chemical degradation of the bone, Raman spectroscopy and statistical tools associated with it, allows the identification of diagenesis classes. These classes will require additional studies, eventually to be a practical support in dating a bone;- The organic alteration of the bone may be due to chemical or bacterial degradation, according to the environment and the postmortem period. Histology can make this distinction. On this period of study, the collagen degradation by chemical hydrolysis is predominant.Conclusion: These parameters form a structural unit, which is well known in archaeological anthropology, and is absolutely transposable in forensic practice if appropriate methodologies are developed. Research on this topic has an essential role as forensics can respond to legitimate requests from victims and their relatives towards justice.

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