Are torque values of preadjusted brackets precise?

OBJECTIVE: The aim of the present study was to verify the torque precision of metallic brackets with MBT prescription using the canine brackets as the representative sample of six commercial brands. MATERIAL AND METHODS: Twenty maxillary and 20 mandibular canine brackets of one of the following commercial brands were selected: 3M Unitek, Abzil, American Orthodontics, TP Orthodontics, Morelli and Ortho Organizers. The torque angle, established by reference points and lines, was measured by an operator using an optical microscope coupled to a computer. The values were compared to those established by the MBT prescription. RESULTS: The results showed that for the maxillary canine brackets, only the Morelli torque (-3.33º) presented statistically significant difference from the proposed values (-7º). For the mandibular canines, American Orthodontics (-6.34º) and Ortho Organizers (-6.25º) presented statistically significant differences from the standards (-6º). Comparing the brands, Morelli presented statistically significant differences in comparison with all the other brands for maxillary canine brackets. For the mandibular canine brackets, there was no statistically significant difference between the brands. CONCLUSIONS: There are significant variations in torque values of some of the brackets assessed, which would clinically compromise the buccolingual positioning of the tooth at the end of orthodontic treatment.

Class II malocclusion occlusal severity description

OBJECTIVES: It is well known that the efficacy and the efficiency of a Class II malocclusion treatment are aspects closely related to the severity of the dental anteroposterior discrepancy. Even though, sample selection based on cephalometric variables without considering the severity of the occlusal anteroposterior discrepancy is still common in current papers. In some of them, when occlusal parameters are chosen, the severity is often neglected. The purpose of this study is to verify the importance given to the classification of Class II malocclusion, based on the criteria used for sample selection in a great number of papers published in the orthodontic journal with the highest impact factor. MATERIAL AND METHODS: A search was performed in PubMed database for full-text research papers referencing Class II malocclusion in the history of the American Journal of Orthodontics and Dentofacial Orthopedics (AJO-DO). RESULTS: A total of 359 papers were retrieved, among which only 72 (20.06%) papers described the occlusal severity of the Class II malocclusion sample. In the other 287 (79.94%) papers that did not specify the anteroposterior discrepancy severity, description was considered to be crucial in 159 (55.40%) of them. CONCLUSIONS: Omission in describing the occlusal severity demands a cautious interpretation of 44.29% of the papers retrieved in this study.

Tratamento ortopédico com aparelho de Herbst: ocorrem mudanças verticais no padrão de crescimento facial?

OBJETIVO: o objetivo deste estudo prospectivo de 32 adolescentes com má oclusão de Classe II, divisão 1, associada a retrognatismo mandibular, tratados com aparelho de Herbst, construído sobre bandas e coroas metálicas, foi avaliar cefalometricamente as possíveis mudanças no padrão de crescimento facial. METODOLOGIA: as telerradiografias laterais foram obtidas ao início do tratamento (T1) e imediatamente após 12 meses de tratamento com o referido aparelho ortopédico (T2). Foram utilizados o quociente de Jarabak e o VERT de Ricketts (modificado) para determinação do padrão facial em T1 e T2. RESULTADOS: utilizando o quociente de Jarabak, os resultados evidenciaram que 27 casos (84,4%) apresentaram padrões hipodivergentes em T1 e permaneceram da mesma forma em T2. Cinco casos (15,6%) apresentaram padrão neutro em T1 e não exibiram mudanças em T2. Quando avaliado o VERT de Ricketts (modificado), não ocorreram mudanças no padrão facial em 31 pacientes. Em apenas um caso ocorreu mudança do tipo facial. CONCLUSÃO: baseado nos resultados obtidos, pode-se concluir que, após 12 meses de tratamento com aparelho de Herbst, não ocorreram mudanças verticais no padrão de crescimento facial dos pacientes estudados.

Epidemiologia do Padrão Face Longa em escolares do Ensino Fundamental do município de Bauru - SP

OBJETIVO: o objetivo deste trabalho foi classificar e determinar a prevalência dos indivíduos portadores de comprometimento vertical nas relações faciais, conforme a severidade da discrepância e, especialmente, dos portadores de Padrão Face Longa. MÉTODOS: a amostra constou de 5.020 sujeitos de nacionalidade brasileira, de ambos os sexos, com idades entre 10 anos e 16 anos e 11 meses, matriculados no Ensino Fundamental do município de Bauru-SP. O exame da morfologia facial constou da observação direta da face, em normas frontal e lateral, sempre com os lábios em repouso, buscando identificar aqueles indivíduos que apresentassem comprometimento vertical nas relações faciais. Esses, uma vez identificados, foram classificados, considerando-se a severidade, em três subtipos: moderado, médio e grave. Para fins de determinação da prevalência dos portadores de Padrão Face Longa, apenas os classificados como dos subtipos médio e grave foram considerados. RESULTADOS: observou-se uma prevalência de 34,94% de comprometimento vertical nas relações faciais e 14,06% de Padrão Face Longa. CONCLUSÃO: os resultados obtidos no presente estudo permitiram concluir que a prevalência do comprometimento vertical nas relações faciais e do Padrão Face Longa foi maior do que a presumida com base na literatura.

Manipulação do genoma humano: ética e direito

A biologia molecular tem fornecido as ferramentas básicas para os geneticistas se aprofundarem nos mecanismos moleculares que influem na variação das doenças. Deve-se destacar a responsabilidade científica e moral dos pesquisadores, uma vez que os cientistas devem imaginar as consequências morais da aplicação comercial de testes genéticos, já que esse fato envolve não só o indivíduo e suas famílias, mas toda a população. Além de ser preciso, também, fazer uma reflexão sobre como essas informações do genoma humano serão utilizadas, para o bem ou mal. O objetivo desta revisão foi trazer à luz do conhecimento dados sobre características éticas da aplicação da biologia molecular, relacionando-a com os direitos do ser humano. Após análise bibliográfica, pôde-se observar que o Projeto Genoma Humano gerou várias possibilidades, como identificação de genes associados a doenças com propriedades sinergísticas, mas modificando às vezes comportamentos ao intervir geneticamente no ser humano, trazendo benefícios ou malefícios sociais. O grande desafio é decidir o que a humanidade pretende em relação a este gigantesco salto.

Evaluation of superficial microhardness in dental enamel with different eruptive ages

This study evaluated the superficial microhardness of enamel in teeth at different posteruptive ages (before eruption in the oral cavity, 2-3 years after eruption, 4-10 years after eruption and more than 10 years after eruption). The study sample was composed of 134 specimens of human enamel. One fragment of each tooth was obtained from the flattest central portion of the crown to produce specimens with 3 x 3 mm. The enamel blocks were minimally flattened out and polished in order to obtain a flat surface parallel to the base, which is fundamental for microhardness testing. Microhardness was measured with a microhardness tester and a Knoop diamond indenter, under a static load of 25 g applied for 5 seconds. Comparison between the superficial microhardness obtained for the different groups was performed by analysis of Student's t test. The results demonstrated that superficial microhardness values have a tendency to increase over the years, with statistically significant difference only between unerupted enamel and that with more than 10 years after eruption. According to the present conditions and methodology, it was concluded that there were differences between the superficial micro-hardness of specimens at different eruptive ages, revealing an increasing mineralization. However, this difference was significant only between unerupted specimens and those with more than 10 years after eruption.

Fluoride release profile of a nanofilled resin-modified glass ionomer cement

The present study aimed to compare the fluoride (F-) release pattern of a nanofilled resin-modified glass ionomer cement (GIC) (Ketac N100 - KN) with available GICs used in dental practice (resin-modified GIC - Vitremer - V; conventional GIC - Ketac Molar - KM) and a nanofilled resin composite (Filtek Supreme - RC). Discs of each material (n=6) were placed into 4 mL of deionized water in sealed polyethylene vials and shaken, for 15 days. F- release (μg F-/cm²) was measured each day using a fluoride-ion specific electrode. Cumulative F- release means were statistically analyzed by linear regression analysis. In order to analyze the differences among materials and the influence of time in the daily F- release, 2-way ANOVA test was performed (α=0.05). The linear fits between the cumulative F- release profiles of RC and KM and time were weak. KN and V presented a strong relationship between cumulative F- release and time. There were significant differences between the daily F- release overtime up to the third day only for GICs materials. The daily F- release means for RC were similar overtime. The results indicate that the F- release profile of the nanofilled resin-modified GIC is comparable to the resin-modified GIC.

Digital subtraction radiographic analysis of the combination of bioabsorbable membrane and bovine morphogenetic protein pool in human periodontal infrabony defects

OBJECTIVES: This study assessed the bone density gain and its relationship with the periodontal clinical parameters in a case series of a regenerative therapy procedure. MATERIAL AND METHODS: Using a split-mouth study design, 10 pairs of infrabony defects from 15 patients were treated with a pool of bovine bone morphogenetic proteins associated with collagen membrane (test sites) or collagen membrane only (control sites). The periodontal healing was clinically and radiographically monitored for six months. Standardized pre-surgical and 6-month postoperative radiographs were digitized for digital subtraction analysis, which showed relative bone density gain in both groups of 0.034 ± 0.423 and 0.105 ± 0.423 in the test and control group, respectively (p>0.05). RESULTS: As regards the area size of bone density change, the influence of the therapy was detected in 2.5 mm² in the test group and 2 mm² in the control group (p>0.05). Additionally, no correlation was observed between the favorable clinical results and the bone density gain measured by digital subtraction radiography (p>0.05). CONCLUSIONS: The findings of this study suggest that the clinical benefit of the regenerative therapy observed did not come with significant bone density gains. Long-term evaluation may lead to a different conclusions.

Influence of different catilever extensions and glass or polyamaramid reinforcement fibers on fracture strength of implant-supported temporary

In long-term oral rehabilitation treatments, resistance of provisional crowns is a very important factor, especially in cases of an extensive edentulous distal space. The aim of this laboratorial study was to evaluate an acrylic resin cantilever-type prosthesis regarding the flexural strength of its in-balance portion as a function of its extension variation and reinforcement by two types of fibers (glass and polyaramid), considering that literature is not conclusive on this subject. Each specimen was composed by 3 total crowns at its mesial portion, each one attached to an implant component (abutment), while the distal portion (cantilever) had two crowns. Each specimen was constructed by injecting acrylic resin into a two-part silicone matrix placed on a metallic base. In each specimen, the crowns were fabricated with either acrylic resin (control group) or acrylic resin reinforced by glass (Fibrante, Angelus) or polyaramide (Kevlar 49, Du Pont) fibers. Compression load was applied on the cantilever, in a point located 7, 14 or 21 mm from the distal surface of the nearest crown with abutment, to simulate different extensions. The specimen was fixed on the metallic base and the force was applied until fracture in a universal test machine. Each one of the 9 sub-groups was composed by 10 specimens. Flexural strength means (in kgf) for the distances of 7, 14 and 21 mm were, respectively, 28.07, 8.27 and 6.39 for control group, 31.89, 9.18 and 5.16 for Kevlar 49 and 30.90, 9.31 and 6.86 for Fibrante. Data analysis ANOVA showed statistically significant difference (p<0.05) only regarding cantilever extension. Tukey's test detected significantly higher flexural strength for the 7 mm-distance, followed by 14 and 21 mm. Fracture was complete only on specimens of non-reinforced groups.

Ressonância magnética nos desarranjos internos da ATM: sensibilidade e especificidade

OBJETIVO: esta revisão de literatura visa avaliar, através de literatura específica, a sensibilidade e especificidade do exame de ressonância magnética (RM) para o diagnóstico dos desarranjos internos da articulação temporomandibular (ATM). METODOLOGIA: tanto artigos que utilizaram ATM de cadáveres para comparar achados anatômicos aos achados de ressonância magnética (RM), como artigos que compararam achados clínicos com achados de RM foram utilizados. Através dos achados desses artigos, as propriedades de sensibilidade e especificidade da RM para o diagnóstico de desarranjos internos da ATM foram calculadas. Com isso, a confiabilidade e a aplicabilidade do exame de RM no diagnóstico dos desarranjos internos da ATM foram discutidas. RESULTADOS: encontrou-se sensibilidade de 90% e especificidade de 88% da RM para desarranjos internos da ATM. CONCLUSÃO: o exame de RM de ATM possui ótima sensibilidade e especificidade para o diagnóstico dos desarranjos internos da ATM. Porém, tal exame deve ser solicitado com cautela, apenas nos casos onde a imagem seja indispensável para o plano de tratamento.

Effects of light-curing time on the cytotoxicity of a restorative composite resin on odontoblast-like cells

This in vitro study evaluated the cytotoxicity of an experimental restorative composite resin subjected to different light-curing regimens. METHODS: Forty round-shaped specimens were prepared and randomly assigned to four experimental groups (n=10), as follows: in Group 1, no light-curing; in Groups 2, 3 and 4, the composite resin specimens were light-cured for 20, 40 or 60 s, respectively. In Group 5, filter paper discs soaked in 5 µL PBS were used as negative controls. The resin specimens and paper discs were placed in wells of 24-well plates in which the odontoblast-like cells MDPC-23 (30,000 cells/cm²) were plated and incubated in a humidified incubator with 5% CO2 and 95% air at 37ºC for 72 h. The cytotoxicity was evaluated by the cell metabolism (MTT assay) and cell morphology (SEM). The data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (p<0.05). RESULTS: In G1, cell metabolism decreased by 86.2%, indicating a severe cytotoxicity of the non-light-cured composite resin. On the other hand, cell metabolism decreased by only 13.3% and 13.5% in G2 and G3, respectively. No cytotoxic effects were observed in G4 and G5. In G1, only a few round-shaped cells with short processes on their cytoplasmic membrane were observed. In the other experimental groups as well as in control group, a number of spindle-shaped cells with long cytoplasmic processes were found. CONCLUSION: Regardless of the photoactivation time used in the present investigation, the experimental composite resin presented mild to no toxic effects to the odontoblast-like MDPC-23 cells. However, intense cytotoxic effects occurred when no light-curing was performed.

Acessibilidade em ambiente universitário: identificação de barreiras arquitetônicas no campus da USP de Bauru

A acessibilidade é um direito do cidadão assegurado por lei para que portadores de deficiência tenham a possibilidade de usufruir de recursos e ações no âmbito social. Barreiras arquitetônicas interferem na vida destes podendo deixá-los a parte da convivência e vida social. Os objetivos deste estudo foram: identificar, descrever e mapear barreiras físicas no Campus da Universidade de São Paulo de Bauru e apresentar as intervenções realizadas, durante o período de outubro de 2001 a dezembro de 2005. O estudo foi descritivo-quantitativo, no qual a coleta de dados centrou-se na análise das condições arquitetônicas das três unidades que compõe este campus, observada as normativas da Associação Brasileira de Normas técnicas e realizada intervenções. Foram identificados: 72 pontos de guias não rebaixadas, 21 pontos de acessos com diferenças de níveis sem rampas; 220m² de escadas/rampas sem corrimãos; 658m² de escadas/rampas com corrimãos em discordância com as normas vigentes; 03 rampas com inclinações superiores às determinadas nas normas técnicas; 10 banheiros parcialmente adaptados para deficientes; 02 vagas de estacionamento parcialmente adaptadas e 02 elevadores existentes. Foram executados, em 19 pontos, rebaixamentos de guias, somando 115 m², com linhas de piso tátil, pintados; 8 rampas; 14 pontos de escadas e rampas externas instaladas com corrimãos e guarda-corpos, 5 vagas exclusivas no estacionamento; instalado 2 centrais de atendimento telefônico para surdo e adquiridas 3 cadeira de rodas. As intervenções realizadas contribuíram para melhorar a acessibilidade de portadores de deficiência no campus favorecendo a utilização dos recursos existentes neste espaço público.

Angioleiomioma de cavidade nasal: relato de um caso e revisão de literatura

Leiomioma de cavidade nasal e seios paranasais é raro. Ele constitui menos de 1% de todos os leiomiomas do corpo humano. Isto se deve à escassez de células musculares no nariz. Estas neoplasias podem ser classificadas em três grupos: leiomioma, angiomioma e leiomioma epitelióide. Somente 15 casos de angiomioma foram encontrados na literatura. O tratamento de escolha é a excisão cirúrgica. Um novo caso e a revisão da literatura são apresentados.

Effect of biofunctionalized implant surface on osseointegration: a histomorphometric study in dogs

Among the different properties that influence bone apposition around implants, the chemical or biochemical composition of implant surface may interfere on its acceptance by the surrounding bone. The aim of this study was to investigate if a biofunctionalization of implant surface influences the bone apposition in a dog model and to compare it with other surfaces, such as a microstructured created by the grit-blasting/acid-etching process. Eight young adult male mongrel dogs had the bilateral mandibular premolars extracted and each one received 6 implants after 12 weeks, totaling 48 implants in the experiment. Four groups of implants were formed with the same microrough topography with or without some kind of biofunctionalization treatment. After histomorphometric analysis, it was observed that the modified microstructured surface with a "low concentration of the bioactive peptide" provided a higher adjacent bone density (54.6%) when compared to the other groups (microstructured + HA coating = 46.0%, microstructured only = 45.3% and microstructured + "high concentration of the bioactive peptide" = 40.7%), but this difference was not statistically significant. In conclusion, biofunctionalization of the implant surface might interfere in the bone apposition around implants, especially in terms of bone density. Different concentrations of bioactive peptide lead to different results.

Inflammation markers in healthy and periodontitis patients: a preliminary data screening

Advances in diagnostic research are moving towards methods whereby the periodontal risk can be identified and quantified by objective measures using biomarkers. Patients with periodontitis may have elevated circulating levels of specific inflammatory markers that can be correlated to the severity of the disease. The purpose of this study was to evaluate whether differences in the serum levels of inflammatory biomarkers are differentially expressed in healthy and periodontitis patients. Twenty-five patients (8 healthy patients and 17 chronic periodontitis patients) were enrolled in the study. A 15 mL blood sample was used for identification of the inflammatory markers, with a human inflammatory flow cytometry multiplex assay. Among 24 assessed cytokines, only 3 (RANTES, MIG and Eotaxin) were statistically different between groups (p<0.05). In conclusion, some of the selected markers of inflammation are differentially expressed in healthy and periodontitis patients. Cytokine profile analysis may be further explored to distinguish the periodontitis patients from the ones free of disease and also to be used as a measure of risk. The present data, however, are limited and larger sample size studies are required to validate the findings of the specific biomarkers.