986 resultados para Diente molar
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Mode of access: Internet.
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A presente pesquisa avaliou a angulação mésio-distal e a distalização dos primeiros e dos segundos molares superiores permanentes em pacientes tratados com o aparelho Forsus® em conjunto com o aparelho ortodôntico fixo. A amostra foi composta por 44 teleradiografias, (22 do lado direito e 22 do lado esquerdo), obtidas por meio de 11 tomografias computadorizadas, de 11 pacientes, realizadas em dois tempos: antes (T1) e após (T2) a instalação do aparelho Forsus®, tratados na clínica de Pós-Graduação em Odontologia, área de Ortodontia, da Universidade Metodista de São Paulo. Após a obtenção dos cortes tipo telerradiografia, foi realizada a marcação dos pontos, linhas e planos, e realizada a mensuração das variáveis de interesse. Para avaliação do espaço para os terceiros molares superiores, utilizou-se uma linha referencial (linha PTVR), demarcada a partir do ponto PTV, perpendicular ao plano de Frankfurt. O espaço avaliado compreendeu entre a Linha PTVR, até a face distal do primeiro molar e do segundo superior permanente. Para avaliar o longo eixo dos primeiros e segundos molares superiores, mensurou-se o ângulo formado entre esses dentes e o plano palatino. Para auxílio das mensurações, foi utilizado o software Radiocef Studio 2. Na análise estatística usou-se o teste t pareado. Concluiu-se que houve distalização e aumento da angulação distal dos primeiros e segundos molares superiores, sendo que nos segundos molares a distalização e angulação distal da coroa ocorreram em menor quantidade; os efeitos do lado direito e esquerdo foram semelhantes; pode-se também constatar que ocorreu uma redução na probabilidade de erupção dos terceiros molares superiores.
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Stable isotope (SI) ratios of carbon (d13C) and nitrogen (d15N) were measured in omnivorous and carnivorous deep-sea copepods of the families Euchaetidae and Aetideidae across the Atlantic sector of the Southern Ocean to establish their trophic positions. Due to high and variable C/N ratios related to differences in lipid content, d13C was corrected using a lipid-normalisation model. d15N signals ranged from 3.0-6.9 per mil in mesopelagic species to 7.0-9.5 per mil in bathypelagic congeners. Among the carnivorous Paraeuchaeta species, the epi- to mesopelagic species Paraeuchaeta antarctica had lower d15N values than the mesopelagic P. rasa and bathypelagic P. barbata. The same trend was observed among omnivorous Aetideidae, but was not significant. In the most abundant species P. antarctica, individuals from the western Atlantic had higher d13C and d15N values than specimens at the eastern stations. These longitudinal changes in d13C and d15N values were attributed to regional differences in hydrography and sea surface temperature (SST), in particular related to a northward extension of the Antarctic Polar Front (APF) at the easternmost stations. The results indicate that even in a mesopelagic carnivorous species, the changes in surface stable isotope signatures are pronounced.
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La apicectomía es una técnica de cirugía odontológica humana y veterinaria, que consiste en la amputación o resección de la porción más apical de la raíz dentaria y la retrobturación del ápice con algún material, con el objetivo de conservar el diente afectado de alguna patología apical. Se han usado gran variedad de materiales para la obturación, como amalgama, gutapercha, ionómero de vidrio, composite, MTA e hidróxido de calcio. En este estudio pretendemos comprobar la viabilidad de la técnica de la realización de la apicectomías en premolares y molares mandibulares, usando distintos materiales de retrobturación como son el iónomero de vidrio Ketac Cem μ® y el composite Tetric EvoFlow® en el conejo de experimentación de raza Neozelandesa. Realizamos las apicectomías de los dientes 407, 408 y 409 (3º premolar, 4º premolar y 1º molar inferior derecho), en una sola fase a diez animales. En el primer diente (407) solo se aplica un sellado del diente apicectomizado con hidróxido de calcio en polvo® y pasta Dycal® Dentin y no se coloca ningún material de obturación. En el segundo diente (408), se aplica un sellado con hidróxido de calcio en polvo® y pasta Dycal® Dentin y encima una retrobturación con ionómero de vidrio Ketac Cem μ® y en el tercer diente (409), se aplica un sellado con hidróxido de calcio en polvo® y pasta Dycal® Dentin y encima una retroturación con el composite Tetric EvoFlow®. A las 4 y 8 semanas se sacrificaron los animales y se realizó la toma de muestras. Estas fueron radiografiadas y posteriormente se realizaron cortes histológicos de los dientes apicectomizados y del tejido alrededor. Los cortes fueron teñidos con la tinción Levai-Laczkó y se realizó el estudio histológico cuantitativo y semicuantitativo, según la norma UNE-EN ISO 10993-6:2007, para medir la presencia de inflamación, fibrosis, infiltrados adiposos y cierre óseo del defecto...
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© 2016 Springer Science+Business Media New YorkResearchers studying mammalian dentitions from functional and adaptive perspectives increasingly have moved towards using dental topography measures that can be estimated from 3D surface scans, which do not require identification of specific homologous landmarks. Here we present molaR, a new R package designed to assist researchers in calculating four commonly used topographic measures: Dirichlet Normal Energy (DNE), Relief Index (RFI), Orientation Patch Count (OPC), and Orientation Patch Count Rotated (OPCR) from surface scans of teeth, enabling a unified application of these informative new metrics. In addition to providing topographic measuring tools, molaR has complimentary plotting functions enabling highly customizable visualization of results. This article gives a detailed description of the DNE measure, walks researchers through installing, operating, and troubleshooting molaR and its functions, and gives an example of a simple comparison that measured teeth of the primates Alouatta and Pithecia in molaR and other available software packages. molaR is a free and open source software extension, which can be found at the doi:10.13140/RG.2.1.3563.4961(molaR v. 2.0) as well as on the Internet repository CRAN, which stores R packages.
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AIMS: (1) To determine if anaesthetic agent bupivacaine, has a prolonged effect on the period of acute postoperative pain when compared to lidocaine, a shorter acting agent. (2) To determine patient’s post-operative satisfaction and preference with regard to anaesthetic choice. METHODS: This double blind, randomised, interventional clinical trial included 85 patients. All patients had bilateral impacted lower third molars of removed under general anaesthetic. All patients received 0.5% plain bupivacaine on one randomly allocated side, with 2% lidocaine (with adrenaline) administered on the opposite side. Pain was measured using visual analogue scales at 0, 30, 60 minutes and 3, 4, 6 and 8 hours post-surgery. Pain was analysed for 1 week following surgery. Psychological evaluations and patient reported outcomes, including patient satisfaction were evaluated. RESULTS: A significant difference in pain (P=0.001) was seen during the 3-8 hour post-operative period. The upper limit of the 95% confidence interval was 10.0 or above at 3hours and 4 hours post-surgery. Two-thirds of patients preferred bupivacaine. CONCLUSION: Longer lasting anaesthetics such as bupivacaine offer a longer period of analgesia, and improve overall patient satisfaction.
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Chitosan is a polysaccharide derived from chitin, mainly of crustacean shells and shrimp wastes. The utilization of chitosan is related to the molar weight and deacetylation degree of the biopolymer. The aim of this work is to study the chitin deacetylation reaction, by the viscosity average molar weight and deacetylation degree of chitosan as a function of reaction time. Deacetylation was carried out in concentrated alkaline solution, 421 g L−1, at 130◦C and the reaction occurred during 4 h. Chitosan paste obtained after 20, 90 and 240 min was used to produce biofilms, which were characterized according water vapor permeability and mechanical properties (tensile strength and percentage tensile elongation at break). During the reaction time deacetylation degree reached 93%, and a 50% reduction in the viscosity average molar weight value in relation to the value of the first 20 min of reaction was found Both reactions presented a kinetic behavior of the pseudo-first order. Biofilm produced from the paste of chitosan with high deacetylation degree showed higher water vapor permeability (WVP), tensile strength (TS) and elongation (E) when compared to films with a low deacetylation.
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In this study, the partial molar volumes of L-serine and L-threonine in aqueous solutions of ammonium sulfate at (0.0, 0.1, 0.3, 0.7, and 1.0) mol.kg(-1) are reported between 278.15 and 308.15 K. Transfer volumes and hydration numbers were obtained, which are larger in L-serine than in L-threonine. Dehydration of the amino acids is observed, rising with the temperature and salt molality. The data suggest that interactions between ions and charged/hydrophilic groups are predominant, and by applying the McMillan and Mayer formalism, it was concluded that they are mainly pair wise. The combination of the data presented in this study with solubility and molecular dynamics data suggests a stronger interaction of the ammonium cation with the zwitterionic centers of the amino acids when compared to the interactions of those centers with the sulfate anion.
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In this work, the partial molar volumes of glycine and DL-alanine in aqueous solutions of ammonium sulfate at 0.0, 0.1, 0.3, 0.7, and 1.0 mol.kg(-1) are determined between 278.15 and 308.15 K. Transfer volumes were obtained, which are larger for glycine than DL-alanine. On the contrary, the hydration numbers are higher for DL-alanine than glycine, and dehydration of the amino acids is observed with increasing temperature or salt molality. The data suggest that interactions between ion and charged/hydrophilic groups are predominant and, by applying the methodology proposed by Friedman and Krishnan, it was concluded that they are mainly pairwise. A group-contribution scheme has been successfully applied to the pairwise volumetric interaction coefficient. Finally, the dehydration effect on glycine, alanine and serine in the presence of different electrolytes has been rationalized in terms of the charge density and a parameter accounting for the cation's hydration.
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La impactación de terceros molares en la región condilar es muy inusual. Este artículo describe el caso de cordal incluido en región subcondilar en una mujer que refirió dolor inespecífico hemifacial y varios episodios de tumefacción. Se describe el manejo quirúrgico de estas inclusiones y se realiza una revisión bibliográfica.
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Aim: To determine if the prevalence of enamel hypoplasia, molar-incisor hypomineralisation (MIH) and deciduous molar hypomineralisation (DMH) is associated with the socioeconomic status of the child and to determine the prevalence of enamel hypoplasia and MIH/DMH comorbidity in the study population. Methods: Information was collected on the sex and socioeconomic status of the 1,169 study participants’ resident in Ile-Ife, Nigeria, recruited through a household survey. The children were clinically examined to assess for the presence of enamel hypoplasia, MIH and DMH. Associations between sex, socioeconomic status and the prevalence of enamel hypoplasia, MIH and DMH were determined. The proportion of children with enamel hypoplasia and MIH/DMH co-morbidity was also determined. Results: Among the 1,169 study participants, 47(4.0%) had MIH, 15 (1.3%) had DMH and 161 (13.8%) had enamel hypoplasia. One (0.09%) study participant had MIH/DMH co-morbidity, 12 (1.0%) had DMH/enamel hypoplasia co-morbidity, and 9 (0.8%) had MIH/hypoplasia co-morbidity. There was no significant association between the socioeconomic status and presence of enamel hypoplasia (p=0.22), MIH (p=0.78) or DMH (p=1.00). Conclusions: The socioeconomic status cannot be used as a distinguishing factor for enamel hypoplasia, MIH and DMH. The possibility of co-existence of enamel hypoplasia and MIH/DMH makes it imperative to find ways to distinguish between the lesions.
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Dissertação (mestrado)—Universidade de Brasília, Faculdade de Ciências da Saúde, Programa de Pós-Graduação em Ciências da Saúde, 2015.