Comparative study of the cephalometric norms for Japanese-Brazilian descents: skeletal and dental measurements

PROPOSIÇÃO: As características cefalométricas, faciais e dentárias, variam consideravelmente entre as diferentes raças. No Brasil, em virtude da grande miscigenação populacional, é necessário conhecer também as variações apresentadas pelas misturas destas raças. Por esta razão, o objetivo deste estudo foi identificar os padrões das variáveis dentárias e esqueléticas de jovens mestiços nipo-brasileiros com oclusão normal e compará-los com amostras semelhantes de leucoderma e de xantoderma. MATERIAL E MÉTODOS: Foram utilizadas 40 telerradiografias de jovens leucodermas, 32 de nipo-brasileiros e 33 de xantodermas. As três amostras apresentavam indivíduos com oclusão normal e face bem balanceada. Foram realizadas as análises estatísticas de covariância (ANCOVA) e o teste t. Basicamente, as variáveis cefalométricas usadas seguiram as análises de Steiner (1953), Tweed (1954) e McNamara Jr (1984). RESULTADOS: Encontrou-se diferença estatística (p < 0,05) entre as raças em 7 das variáveis estudadas. Estas diferenças indicaram um padrão mais vertical, menor ângulo interincisivos e menor sobremordida para a amostra nipobrasileira, com relação à amostra leucoderma, porém valores semelhantes aos da amostra xantoderma. CONCLUSÕES: Os valores esqueléticos e dentários encontrados para os jovens nipo-brasileiros foram, em geral, intermediários aos das amostras leucoderma e xantoderma, entretanto, mais similares àqueles da amostra de xantoderma, o que fortalece a necessidade de conhecer o padrão específico deste grupo de mestiços.OBJECTIVE: The objective of this study was to identify the standards for skeletal and dental measurements of adolescent Japanese-Brazilian descents with normal occlusion and also to compare it with a similar White and Japanese sample. MATERIAL AND METHODS: Lateral cephalometric radiographs were used with the purpose of comparison between the groups: White (N=40), Japanese-Brazilian (N=32) and Japanese (n=33). The statistical tests were the t test and ANCOVA. Basically, the cephalometric measurements used followed the analyses of Steiner (1953), Tweed (1954) and McNamara Jr (1984). RESULTS: The statistical differences (p < .05) indicated a more accentuated vertical pattern, smaller interincisal angle and overbite for the Japanese-Brazilian sample, when compared to the White sample, although with similar values to the Japanese group. CONCLUSION: The skeletal and dental standards found for the Japanese-Brazilian descents were, in general, similar to those of the Japanese sample but diverse to the White sample. This empowers the necessity to discern this Japanese-Brazilian descents pattern

Load-deflection study of caliber 0.014 nickel-titanium orthodontic wires

PROPOSIÇÃO: O objetivo desta pesquisa foi apresentar a magnitude e a constância das forças liberadas por fios ortodônticos de níquel-titânio, usados para a correção dos apinhamentos dentários. Outro objetivo foi comparar os dois meios mais utilizados de avaliação da deflexão elástica destes fios: o teste de 3 pontos e o dispositivo de simulação clínica. MATERIAL E MÉTODOS: Foram avaliados 11 grupos de fios de liga predominantemente de níquel-titânio, calibre 0,014, de 6 marcas diferentes (Abzil convencional e termoativado; GAC convencional e termoativado; Morelli convencional e termoativado; Ormco CuNiTi; Orthometric convencional e termoativado e Orthosource convencional e termoativado), em teste de deflexão elástica, nas deflexões de 0,5; 1; 2 e 3mm. Uma máquina de ensaio universal INSTRON 3342, com célula de carga de 10N foi utilizada e, como protocolo, foi seguida a norma ISO 15.841. Para a análise estatística dos resultados foram utilizados os testes: Kolmogorov-Smirnov, para conferir se havia normalidade; teste t independente, para comparação dos resultados do teste de 3 pontos e dos resultados do dispositivo; e o teste ANOVA seguido do teste de Tukey, para comparações entre grupos. RESULTADOS: Houve diferença estatística entre os resultados gerados pelo teste de 3 pontos e os gerados pelo dispositivo. Por ser o teste indicado pela norma ISO citada, somente os resultados do teste de 3 pontos foram considerados. Todos os fios estudados apresentaram pseudoelasticidade em uma faixa de variação de força de até 40cN. Os grupos Abzil convencional, GAC convencional, Morelli termoativado, Ormco CuNiTi e Orthometric convencional apresentaram força dentro de uma faixa considerada ótima para a indução da movimentação dentária (50cN-100cN). Os fios termoativados liberaram forças mais leves que seus pares convencionais. CONCLUSÕES: Dentre os grupos estudados, aqueles que apresentaram pseudoelasticidade, forças dentro de uma faixa considerada ótima e homogeneidade de amostra, foram os grupos Morelli termoativado e Ormco CuNiTi.OBJECTIVE: The purpose of this study was to present the magnitude and the constancy of the forces released by nickel-titanium orthodontic wires, used to treat dental crowding. Another purpose was to compare the most usual types of bending tests used to evaluate these wires: 3-point test and clinical simulation device. MATERIAL AND METHODS: Eleven groups of orthodontic nickel-titanium wires, caliber 0.014, of 6 different brands (Abzil conventional and heat-activated; GAC conventional and heat-activated; Morelli conventional and heat-activated; Ormco CuNiTi; Orthometric conventional and heat-activated and Orthosource conventional and heat-activated) were tested by bending test, at deflections of 0.5; 1; 2 and 3mm. A universal testing machine INSTRON 3342 with a 10N load cell was used and, in order to standardize the tests, the ISO 15.841 regulation was followed. Statistical analysis was performed using the subsequent tests: Kolmogorov-Smirnov to verify normality; independent t test to compare the results of the 3-point test and the results derived from the device, and ANOVA followed by the Tukey test for intergroup comparisons. RESULTS: There were significant differences between the results of the 3-point test and the device. As indicated by the ISO regulation, only the results from the 3-point bending test were considered. All groups were classified as pseudoelastic, within a load range of 40cN, at maximum. The groups Abzil conventional, GAC conventional, Morelli heat-activated, Ormco CuNiTi and Orthometric conventional released load within optimum range (50cN-100cN). Heatactivated wires released lower load compared to conventional wire of the same brand. CONCLUSIONS: Among the groups evaluated those that presented pseudoelasticity, load within a range considered optimal, in a homogeneous manner, were Morelli heat-activated and Ormco CuNiTi

Analysis of social impacts of large hydroelectric projects: the case of Belo Monte AHE

Submitted by Gilvan Almeida ([email protected]) on 2016-08-10T18:28:39Z No. of bitstreams: 2 620.pdf: 778722 bytes, checksum: f1d1208ba8bbe2994b224fb84e121c33 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Approved for entry into archive by Maria Arruda ([email protected]) on 2018-02-01T13:36:42Z (GMT) No. of bitstreams: 2 620.pdf: 778722 bytes, checksum: f1d1208ba8bbe2994b224fb84e121c33 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2018-02-01T13:36:42Z (GMT). No. of bitstreams: 2 620.pdf: 778722 bytes, checksum: f1d1208ba8bbe2994b224fb84e121c33 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, Brasil.O objetivo do estudo foi analisar os impactos sociais potenciais do Aproveitamento Hidrelétrico Belo Monte. O Método documental foi utilizado para análise crítica do conteúdo referente aos impactos sociais previstos nos Estudos de Impacto Ambiental (EIA), visando identificar as instâncias de aprendizados de lições anteriores e os erros reincidentes, com base nas experiências dos Projetos Hidrelétricos Tucuruí (Brasil) e de James Bay (Canadá). A política ambiental evoluiu, mas não a ponto de consolidar as diretrizes no nível prático, estabelecido pelo próprio marco regulatório, no entanto, a Avaliação de Impacto Social ainda é minimizada na fase de planejamento dos projetos hidrelétricos, prevalecendo o critério remediador do impacto social

Demystifying self-ligating brackets

Atualmente, os braquetes autoligáveis têm sido associados a tratamentos mais rápidos e eficazes, o que desperta a curiosidade em compará-los ao sistema convencional. Ao contrário dos braquetes tradicionais, os autoligáveis não necessitam de ligaduras, sejam elásticas ou metálicas. A literatura é farta em concluir que essa característica diminui, ostensivamente, a resistência do atrito durante as mecânicas de deslize. Além disso, existem alegações sobre a dimimuição da necessidade de extrações e de expansão maxilar com o uso desses acessórios. Portanto, o objetivo dessa revisão de literatura foi buscar os mais novos estudos a respeito dos aparelhos autoligáveis atualmente utilizados nos tratamentos ortodônticos, confirmando ou retificando as especulações vigentes.Currently self-ligating brackets have been associated to faster and more efficient treatments, which arouse the curiosity to compare them to the conventional system. Unlike traditional appliances, self-ligating brackets do not require elastomeric or metal ligatures. The literature is abundant in concluding that this feature decreases, ostensibly, the friction resistance during the sliding mechanics. Moreover, there are reports on minimizing the need of extractions and maxillary expansion using these accessories. Therefore, the purpose of this literature review was to seek the newest studies about the self-ligating brackets currently used in orthodontic treatments, confirming or correcting current speculations

Dual embryonic origin of maxillary lateral incisors: clinical implications in patients with cleft lip and palate

Introduction:Cleft lip and palate are craniofacial anomalies highly prevalent in the overall population. In oral clefts involving the alveolar ridge, variations of number, shape, size and position are observed in maxillary lateral incisors. The objective of this manuscript is to elucidate the embryonic origin of maxillary lateral incisors in order to understand the etiology of these variations.Contextualization: The hypothesis that orofacial clefts would split maxillary lateral incisor buds has been previously reported. However, recent studies showed that maxillary lateral incisors have dual embryonic origin, being partially formed by both the medial nasal process and the maxillary process. In other words, the mesial half of the lateral incisor seems to come from the medial nasal process while the distal half of the lateral incisor originates from the maxillary process. In cleft patients, these processes do not fuse, which results in different numerical and positional patterns for lateral incisors relating to the alveolar cleft. In addition to these considerations, this study proposes a nomenclature for maxillary lateral incisors in patients with cleft lip and palate, based on embryology and lateral incisors position in relation to the alveolar cleft.Conclusion:Embryological knowledge on the dual origin of maxillary lateral incisors and the use of a proper nomenclature for their numerical and positional variations renders appropriate communication among professionals and treatment planning easier, in addition to standardizing research analysis

Comparison of mesiodistal tooth widths in Caucasian, African and Japanese individuals with Brazilian ancestry and normal occlusion

OBJECTIVE: To observe the presence of sexual dimorphism and compare the mesiodistal width of the teeth in Caucasian, African and Japanese individuals with Brazilian ancestry not orthodontically treated and with normal occlusion. METHODS: One hundred pairs of dental casts were used. It was measured, from first molar to first molar in both arches, the teeth's mesiodistal widths, using a digital caliper. For the statistical analysis of results Kolmogorov-Smirnov, t test, ANOVA and Tukey's test (p < 0.05) were used. RESULTS: Sexual dimorphism occurred on the three evaluated groups, and the highest mesiodistal widths were found in males. There was statistically significant difference between racial groups in all evaluated teeth in males. However, in females, this same difference was found only on upper lateral incisor and first molar; and lower lateral incisor, canine, first premolar and first molar. CONCLUSION: Most of mesiodistal measures present particular characteristics in relation to gender, with higher values for males, and to race, with a tendency for African to present greater mesiodistal distance of the teeth, followed by Japanese and Caucasians, respectively, important for the correct diagnosis and orthodontic planning

Comparative study of dental cephalometric patterns of Japanese-Brazilian, Caucasian and Mongoloid patients

INTRODUCTION: The objective of this study was to identify the patterns of dental variables of adolescent Japanese-Brazilian descents with normal occlusion, and also to compare them with a similar Caucasian and Mongoloid sample. METHODS: Lateral cephalometric radiographs were used to compare the groups: Caucasian (n = 40), Japanese-Brazilian (n = 32) and Mongoloid (n = 33). The statistical tests used were one-way ANOVA and ANCOVA. The cephalometric measurements used followed the analyses of Steiner, Tweed and McNamara Jr. RESULTS: Statistical differences (P < 0.05) indicated a smaller interincisal angle and overbite for the Japanese-Brazilian sample, when compared to the Caucasian sample, although with similar values to the Mongoloid group. CONCLUSION: The dental patterns found for the Japanese-Brazilian descents were, in general, more similar to those of the Mongoloid sample