Clinical evaluation of dental alignment and leveling with three different

INTRODUCTION: A wide variety of orthodontic wires made of different alloys is available to be used in orthodontic practice and may produce different clinical responses during tooth movement. OBJECTIVE: This research evaluated the alignment and leveling of lower dental arches after the use of three types of orthodontic wires. METHODS: A sample of 36 patients was randomly divided into 3 groups: stainless steel, multistranded steel and superelastic nickel-titanium, according to the first leveling arches used. In order to observe differences in tooth position and axial inclination of the lower incisors, all patients had lateral cephalometric radiographs taken before the insertion of the first arches and 2 months later. The irregularity index and the curve of Spee were measured, compared between groups and considered influential on the proclination of incisors during the initial phase of alignment and leveling. The Reflex microscope was used to measure the irregularity index, whereas the ANOVA analysis of variance was used to verify differences between groups with regard to the degree of dental alignment and leveling. RESULTS: There were significant differences between groups only at T2 for the irregularity index. CONCLUSION: The NiTi and multistranded steel wires showed greater aligning capacity when compared with stainless steel wires.INTRODUÇÃO: uma grande variedade de fios ortodônticos, compostos por diferentes ligas, está disponível para utilização ortodôntica, podendo gerar respostas clínicas diversas, durante a movimentação dentária. OBJETIVO: este trabalho visa a avaliar o alinhamento e nivelamento das arcadas dentárias inferiores, após a utilização de três tipos de fios ortodônticos. MÉTODOS: uma amostra de 36 pacientes foi aleatoriamente dividida em três grupos, de acordo com os primeiros arcos utilizados para o alinhamento e nivelamento: aço inoxidável convencional, aço multifilamentado e de níquel-titânio superelástico. Para se avaliar as diferenças relacionadas ao posicionamento dentário e inclinação axial dos incisivos inferiores, foram obtidas radiografias cefalométricas de perfil, de todos os pacientes, em duas fases do tratamento: antes da inserção dos primeiros arcos e dois meses após a inserção dos mesmos. O índice de irregularidade dentária (IID) e a profundidade inicial de curva de Spee, fatores influentes sobre a projeção de incisivos durante a fase inicial de alinhamento e nivelamento, foram avaliados e comparados intra- e intergrupos. Para a medição do IID, foi utilizado o Reflex Microscope, possibilitando a mensuração do grau de alinhamento e nivelamento dentário em terceira dimensão. A análise de variância (ANOVA) foi utilizada para se avaliar as diferenças intergrupos em relação ao grau de alinhamento e nivelamento dentário. RESULTADOS: diferenças estatisticamente significativas intergrupos somente foram encontradas em T2, em relação ao índice de irregularidade dentária, já que os fios de NiTi e aço multifilamentado apresentaram maior capacidade de alinhamento do que os fios de aço inoxidável convencionais

Dental Occlusion in a Split Amazon Indigenous Population: Genetics Prevails over Environment

Background: Studies examining human and nonhuman primates have supported the hypothesis that the recent increase in the occurrence of misalignment of teeth and/or incorrect relation of dental arches, named dental malocclusion, is mainly attributed to the availability of a more processed diet and the reduced need for powerful masticatory action. For the first time on live human populations, genetic and tooth wear influences on occlusal variation were examined in a split indigenous population. The Arara-Iriri people are descendants of a single couple expelled from a larger village. In the resultant village, expansion occurred through the mating of close relatives, resulting in marked genetic cohesion with substantial genetic differences. Methodology/Principal Findings: Dental malocclusion, tooth wear and inbreeding coefficient were evaluated. The sample examined was composed of 176 individuals from both villages. Prevalence Ratio and descriptive differences in the outcomes frequency for each developmental stage of the dentition were considered. Statistical differences between the villages were examined using the chi-square test or Fisher’s exact statistic. Tooth wear and the inbreeding coefficient (F) between the villages was tested with Mann-Whitney statistics. All the statistics were performed using two-tailed distribution at p#0.05. The coefficient inbreeding (F) confirmed the frequent incestuous unions among the Arara-Iriri indigenous group. Despite the tooth wear similarities, we found a striking difference in occlusal patterns between the two Arara villages. In the original village, dental malocclusion was present in about one third of the population; whilst in the resultant village, the occurrence was almost doubled. Furthermore, the morphological characteristics of malocclusion were strongly different between the groups. Conclusions/Significance: Our findings downplay the widespread influence of tooth wear, a direct evidence of what an individual ate in the past, on occlusal variation of living human populations. They also suggest that genetics plays the most important role on dental malocclusion etiology

Relationship of tooth wear to chronological age among indigenous Amazon populations.

In indigenous populations, age can be estimated based on family structure and physical examination. However, the accuracy of such methods is questionable. The aim of this cross-sectional study was to evaluate occlusal tooth wear related to estimated age in the remote indigenous populations of the Xingu River, Amazon. Two hundred and twenty three semi-isolated indigenous subjects with permanent dentition from the Arara (n = 117), Xicrin-Kayapó (n = 60) and Assurini (n = 46) villages were examined. The control group consisted of 40 non-indigenous individuals living in an urban area in the Amazon basin (Belem). A modified tooth wear index was applied and then associated with chronological age by linear regression analysis. A strong association was found between tooth wear and chronological age in the indigenous populations (p <0.001). Tooth wear measurements were able to explain 86% of the variation in the ages of the Arara sample, 70% of the Xicrin-Kaiapó sample and 65% of the Assurini sample. In the urban control sample, only 12% of ages could be determined by tooth wear. These findings suggest that tooth wear is a poor estimator of chronological age in the urban population; however, it has a strong association with age for the more remote indigenous populations. Consequently, these findings suggest that a simple tooth wear evaluation method, as described and applied in this study, can be used to provide a straightforward and efficient means to assist in age determination of newly contacted indigenous groups

Analysis of the use of sample size calculation and error of method in researches published in Brazilian and international orthodontic journals

To evaluate, quantitatively, how often the researchers of orthodontic science have used the calculation of sample size and evaluated the method error in studies published in Brazil and in the United States of America.Esta investigação tem o objetivo de avaliar, quantitativamente, com que frequência os pesquisadores da ciência ortodôntica têm empregado o cálculo amostral e a análise do erro do método em pesquisas publicadas no Brasil e nos Estados Unidos

Mechanical properties of NiTi and CuNiTi shape-memory wires used in orthodontic treatment. Part 1: stress-strain tests

OBJECTIVE: This research aimed to compare, through traction tests, eight types of superelastic and heat-activated NiTi archwires, by six trade companies (GAC, TP, Ormco, Masel, Morelli and Unitek) to those with addition of copper (CuNiTi 27ºC and 35ºC, Ormco). METHODS: The tests were performed in an EMIC mechanical testing machine, model DL10000, capacity of 10 tons, at the Military Institute of Engineering (IME). RESULTS: The results showed that, generally, heat-activated NiTi archwires presented slighter deactivation loadings in relation to superelastic. Among the archwires that presented deactivation loadings biologically more adequate are the heat-activated by GAC and by Unitek. Among the superelastic NiTi, the CuNiTi 27ºC by Ormco were the ones that presented slighter deactivation loadings, being statistically (ANOVA) similar, to the ones presented by the heat-activated NiTi archwires by Unitek. When compared the CuNiTi 27ºC and 35ºC archwires, it was observed that the 27ºC presented deactivation forces of, nearly, &#8531; of the presented by the 35ºC. CONCLUSION: It was concluded that the CuNiTi 35ºC archwires presented deactivation loadings biologically less favorable in relation to the other heat-activated NiTi archwires, associated to lower percentage of deformation, on the constant baselines of deactivation, showing less adequate mechanical behavior, under traction, in relation to the other archwires

Brachycephalic, dolichocephalic and mesocephalic: is it appropriate to describe the face using skull patterns?

The use of a standardized terminology in the medical sciences is essential for both clinical practice and scientific research. In addition to facilitating communication between professionals, it enhances the reliability of comparisons made between studies from different areas, thereby contributing to a higher level of scientific evidence. Examples of attempts made to standardize the terminology in other areas dedicated to the study of craniofacial morphology can be found in the literature. On the other hand, one can find in the orthodontic literature a variety of terms that render the consensus and communication between orthodontists and other researchers even more problematic. As an example, one could cite the use of the terms brachyfacial, mesofacial and dolichofacial, which form part of a cranial index terminology used to describe facial types. Thus, a reflection on the origin and differences of the terms used to describe the human facial phenotype may pave the way toward a consensus regarding the meaning that best represents the craniofacial patterns

Sample size (n) and mean age (years) in the Arara-Laranjal and Arara-Iriri villages.

<p>Sample size (n) and mean age (years) in the Arara-Laranjal and Arara-Iriri villages.</p