Digital radiography as an alternative method in the evaluation of bone density in uremic rats / Radiografia digital como método alternativo na avaliação da densidade óssea em ratos urêmicos

ABSTRACT Introduction: Digital radiography (DRx) may provide a suitable alternative to investigate mineral and bone disorder (MBD) and loss of bone density (BD) in rodent models of chronic kidney disease (CKD). The objective of this study was to use DRx to evaluate BD in CKD rats, and to evaluate the correlation between DRx findings and serum MBD markers and bone histomorphometry. Methods: Uremia was induced by feeding Wistar rats an adenine-enriched diet (0.75% for 4 weeks/0.10% for 3 weeks); outcomes were compared to a control group at experimental weeks 3, 4, and 7. The following biochemical markers were measured: creatinine clearance (CrC), phosphate (P), calcium (Ca), fractional excretion of P (FeP), alkaline phosphatase (ALP), fibroblast growth factor-23 (FGF-23), and parathyroid hormone (PTH). DRx imaging was performed and histomorphometry analysis was conducted using the left femur. Results: As expected, at week 7, uremic rats presented with reduced CrC and higher levels of P, FeP, and ALP compared to controls. DRx confirmed the lower BD in uremic animals (0.57±0.07 vs. 0.68 ± 0.06 a.u.; p = 0.016) compared to controls at the end of week 7, when MBD was more prominent. A severe form of high-turnover bone disease accompanied these biochemical changes. BD measured on DRx correlated to P (r=-0.81; p = 0.002), ALP (r = -0.69, p = 0.01), PTH (r = -0.83, p = 0.01), OS/BS (r = -0.70; p = 0.02), and ObS/BS (r = -0.70; p = 0.02). Conclusion: BD quantified by DRx was associated with the typical complications of MBD in CKD and showed to be viable in the evaluation of bone alterations in CKD.

RESUMO Introdução: A radiografia digital (RxD) pode representar uma alternativa adequada para investigar o distúrbio mineral e ósseo (DMO) e a perda de densidade óssea (DO) em modelos de roedores da doença renal crônica (DRC). O objetivo deste estudo foi utilizar a RxD para avaliar a DO em ratos com DRC, e avaliar a correlação entre os achados da RxD e marcadores séricos de DMO e histomorfometria óssea. Métodos: A uremia foi induzida pela alimentação de ratos Wistar com dieta enriquecida com adenina (0,75% por 4 semanas/0,10% por 3 semanas); os resultados foram comparados com um grupo controle nas semanas experimentais 3, 4 e 7. Os seguintes marcadores bioquímicos foram medidos: clearance de creatinina (CCr), fosfato (P), cálcio (Ca), fração excretada de P (FeP), fosfatase alcalina (ALP), fator de crescimento de fibroblastos-23 (FGF-23) e paratormônio (PTH). A imagem da RxD foi obtida e a análise histomorfométrica foi realizada com o fêmur esquerdo. Resultados: como esperado, na semana 7, os ratos urêmicos apresentaram redução do CCr e níveis mais altos de P, FeP e ALP em comparação aos controles. A RxD confirmou a menor DO em animais urêmicos (0,57 ± 0,07 vs. 0,68 ± 0,06 u.a.; p = 0,016) em comparação aos controles no final da semana 7, quando a DMO foi mais proeminente. Uma forma grave de doença óssea de alta renovação celular acompanhou essas mudanças bioquímicas. A DO, medida na RxD foi correlacionada a P (r = -0,81; p = 0,002), ALP (r = -0,69, p = 0,01), PTH (r = -0,83, p = 0,01), OS/BS (r = -0,70 p = 0,02) e Ob.S/BS (r = -0,70; p = 0,02). Conclusão: A DO quantificada por RxD esteve associada às complicações típicas da DMO na DRC e mostrou-se viável na avaliação de alterações ósseas na DRC.

Digital radiography as an alternative method in the evaluation of bone density in uremic rats.

INTRODUCTION: Digital radiography (DRx) may provide a suitable alternative to investigate mineral and bone disorder (MBD) and loss of bone density (BD) in rodent models of chronic kidney disease (CKD). The objective of this study was to use DRx to evaluate BD in CKD rats, and to evaluate the correlation between DRx findings and serum MBD markers and bone histomorphometry. METHODS: Uremia was induced by feeding Wistar rats an adenine-enriched diet (0.75% for 4 weeks/0.10% for 3 weeks); outcomes were compared to a control group at experimental weeks 3, 4, and 7. The following biochemical markers were measured: creatinine clearance (CrC), phosphate (P), calcium (Ca), fractional excretion of P (FeP), alkaline phosphatase (ALP), fibroblast growth factor-23 (FGF-23), and parathyroid hormone (PTH). DRx imaging was performed and histomorphometry analysis was conducted using the left femur. RESULTS: As expected, at week 7, uremic rats presented with reduced CrC and higher levels of P, FeP, and ALP compared to controls. DRx confirmed the lower BD in uremic animals (0.57±0.07 vs. 0.68 ± 0.06 a.u.; p = 0.016) compared to controls at the end of week 7, when MBD was more prominent. A severe form of high-turnover bone disease accompanied these biochemical changes. BD measured on DRx correlated to P (r=-0.81; p = 0.002), ALP (r = -0.69, p = 0.01), PTH (r = -0.83, p = 0.01), OS/BS (r = -0.70; p = 0.02), and ObS/BS (r = -0.70; p = 0.02). CONCLUSION: BD quantified by DRx was associated with the typical complications of MBD in CKD and showed to be viable in the evaluation of bone alterations in CKD.

Evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics.

OBJECTIVE: To evaluate and compare "in vitro" the maximum friction force generated by three types of esthetic brackets, two types of polycrystalline conventional ceramic brackets (20/40 and InVu) and one type of sapphire monocrystalline bracket (Radiance) in dry and artificial saliva wet settings. Also, to evaluate the influence exerted by artificial saliva on the friction forces of those brackets. METHODS: Tests were performed in dry and artificial saliva wet setting (Oral Balance) by using an EMIC DL 10000 testing machine, simulating a 2 mm slide of 0.019 x 0.025-in rectangular stainless steel wires over the pre-angulated and pre-torqued (right superior canine, Roth prescription, slot 0.022 x 0.030-in) brackets (n = 18 for each bracket). In order to compare groups in dry and wet settings, the ANOVA was used. For comparisons related to the dry versus wet setting, the student t test was used for each group. RESULTS: The results showed that in the absence of saliva the Radiance monocrystalline brackets showed the highest friction coefficients, followed by the 20/40 and the InVu polycrystalline brackets. In tests with artificial saliva, the Radiance and the 20/40 brackets had statistically similar friction coefficients and both were greater than that presented by the InVu brackets. The artificial saliva did not change the maximum friction force of the Radiance brackets, but, for the others (20/40 and InVu), an increase of friction was observed in its presence. CONCLUSION: The InVu brackets showed, in the absence and in the presence of saliva, the lowest friction coefficient.

Evaluation of the friction force generated by monocristalyne and policristalyne ceramic brackets in sliding mechanics

OBJECTIVE: To evaluate and compare "in vitro" the maximum friction force generated by three types of esthetic brackets, two types of polycrystalline conventional ceramic brackets (20/40 and InVu) and one type of sapphire monocrystalline bracket (Radiance) in dry and artificial saliva wet settings. Also, to evaluate the influence exerted by artificial saliva on the friction forces of those brackets. METHODS: Tests were performed in dry and artificial saliva wet setting (Oral Balance) by using an EMIC DL 10000 testing machine, simulating a 2 mm slide of 0.019 x 0.025-in rectangular stainless steel wires over the pre-angulated and pre-torqued (right superior canine, Roth prescription, slot 0.022 x 0.030-in) brackets (n = 18 for each bracket). In order to compare groups in dry and wet settings, the ANOVA was used. For comparisons related to the dry versus wet setting, the student t test was used for each group. RESULTS: The results showed that in the absence of saliva the Radiance monocrystalline brackets showed the highest friction coefficients, followed by the 20/40 and the InVu polycrystalline brackets. In tests with artificial saliva, the Radiance and the 20/40 brackets had statistically similar friction coefficients and both were greater than that presented by the InVu brackets. The artificial saliva did not change the maximum friction force of the Radiance brackets, but, for the others (20/40 and InVu), an increase of friction was observed in its presence. CONCLUSION: The InVu brackets showed, in the absence and in the presence of saliva, the lowest friction coefficient.

OBJETIVO: avaliar e comparar in vitro as cargas máximas de atrito geradas por três tipos de braquetes estéticos, sendo dois deles cerâmicos policristalinos convencionais (20/40 e InVu) e um monocristalino de safira (Radiance), em ambientes seco e umedecido por saliva artificial. Também avaliar a influência exercida pela saliva artificial sobre as cargas de atrito dos referidos braquetes. MÉTODOS: os ensaios foram realizados em ambiente seco e em ambiente umedecido com saliva artificial em gel (Oral Balance), utilizando uma máquina de ensaios mecânicos (EMIC, modelo DL10000), simulando um deslizamento de 2mm de fios retangulares 0,019" x 0,025" de aço sobre os braquetes (n = 18, para cada braquete), pré-angulados e pré-torqueados (canino superior direito prescrição Roth, slot 0,022" x 0,030"). Para comparação entre os braquetes, em ambiente seco ou umedecido, utilizou-se a análise de variância; e para a comparação dos braquetes em ambiente seco e umedecido, utilizou-se o teste t para amostras independentes. RESULTADOS: os resultados obtidos indicaram que, na ausência de saliva, os braquetes monocristalinos Radiance demonstraram o maior coeficiente de atrito, seguidos pelos braquetes policristalinos 20/40 e InVu. Nos ensaios realizados em ambiente umedecido, os braquetes Radiance e 20/40 apresentaram coeficientes de atrito estatisticamente semelhantes, e superiores ao apresentado pelos braquetes InVu. A saliva artificial não promoveu alterações na força máxima de atrito para os braquetes Radiance; todavia, para os demais (20/40 e InVu), promoveu aumento significativo nos coeficientes de atrito. CONCLUSÃO: os braquetes InVu apresentaram, tanto nos ensaios realizados na ausência, quanto na presença de saliva, os menores coeficientes de atrito, entre os braquetes ensaiados.

The effect of the Ginkgo biloba extract in the expression of Bax, Bcl-2 and bone mineral content of Wistar rats with glucocorticoid-induced osteoporosis.

OBJECTIVE: Evaluate the effects of the extract of Ginkgo biloba (EGb) in the glucocorticoid-induced-osteoporosis through the Bax and Bcl-2 expressions by osteoblast cells, the x-ray and bone density of the tibia. METHOD: Rats were divided into five groups: osteoporosis; EGb1 (28 mg/kg); EGb2 (56 mg/kg); alendronate (0.2 mg/animal) and control. The treatments were conducted for 20 (n = 30) and 30 days (n = 30). The Bax and Bcl-2 expressions were evaluated in osteoblasts of the mandibular alveolar bone. The tibias were radiographed to evaluate the X-ray and bone density. The control group was compared with the osteoporosis' (Student's t-test/Mann-Whitney). The other groups were analyzed by analysis of variance test followed by Dunnett/Dunnett T3 (p < 0.05). RESULTS: When compared the osteoporosis to the control group (p <0.05): Bax and x-ray density increased; Bcl-2 and the bone density reduced. When compared with the osteoporosis group (p < 0.05), alendronate (30 days), EGb1 and EGb2 (20/30 days) increased the Bcl-2 expression; EGb2 and alendronate (20 days) EGb1 and EGb2 (30 days) reduced the Bax expression; and EGb1 and EGb2 (20/30 days) reduced the X-ray density. CONCLUSIONS: The EGb improved the Bcl-2 and reduced the Bax expression by osteoblasts in the mandibular alveolar bone and recovered the mineral content in the tibia of rats with glucocorticoid-induced-osteoporosis.

Low-level laser therapy decreases renal interstitial fibrosis.

OBJECTIVE: the purpose of this study was to investigate the effect of low-level laser therapy (LLLT) on chronic kidney disease (CKD) in a model of unilateral ureteral obstruction (UUO). BACKGROUND DATA: Regardless of the etiology, CKD involves progressive widespread tissue fibrosis, tubular atrophy, and loss of kidney function. This process also occurs in kidney allograft. At present, effective therapies for this condition are lacking. We investigated the effects of LLLT on the interstitial fibrosis that occurs after experimental UUO in rats. METHODS: The occluded kidney of half of the 32 Wistar rats that underwent UUO received a single intraoperative dose of LLLT (AlGaAs laser, 780 nm, 22.5 J/cm(2), 30 mW, 0.75 W/cm(2), 30 sec on each of nine points). After 14 days, renal fibrosis was assessed by Sirius red staining under polarized light. Immunohistochemical analyses quantitated the renal tissue cells that expressed fibroblast (FSP-1) and myofibroblast (α-SMA) markers. Reverse transcriptase polymerase chain reaction (RT-PCR) was performed to determine the mRNA expression of interleukin (IL)-6, monocyte chemotactic protein-1 (MCP-1), transforming growth factor (TGF)-ß1 and Smad3. RESULTS: The UUO and LLLT animals had less fibrosis than the UUO animals, as well having decreased expression inflammatory and pro-fibrotic markers. CONCLUSIONS: For the first time, we showed that LLLT had a protective effect regarding renal interstitial fibrosis. It is conceivable that by attenuating inflammation, LLLT can prevent tubular activation and transdifferentiation, which are the two processes that mainly drive the renal fibrosis of the UUO model.

Influencia de los diferentes sistemas adhesivos en la resistencia de la unión al microcizallamiento en superficies dentarias erosionadas / Influence of different adhesive systems on bond strength to tooth surfaces eroded microshear

El objetivo fue analizar in vitro la resistencia de la unión al cizallamiento de sistemas adhesivos convencional y autocondicionante sobre la superficie de esmalte y dentina después del proceso erosivo ocasionado por una bebida ácida. Cuarenta incisivos bovinos fueron seccionados y desgastados hasta obtener superficies planas en esmalte y dentina. Sobre estas, fue simulado un proceso erosivo utilizando Coca-Cola® por 10 días, 4 veces al día durante 10 min. Después, las muestras fueron divididas en 4 grupos: G1-esmalte y G2-dentina, ambas superficies hibridizadas con adhesivo convencional (Adper Single Bond II); G3-esmalte y G4-dentina, hibridizados con sistema autocondicionante (Clearfil SE Bond). Cilindros de resina compuesta (Filtek Flow Z350) con 2 mm. de altura por 0,8 mm. de diámetro fueron confeccionados y almacenados en agua deionizada a 37º C por 24h. Terminado el período, fueron sometidos al test de microcizallamiento en Emic DL 2000 con una velocidad de 1mm/min. hasta la fractura. Los resultados fueron sometidos al análisis estadístico (ANOVA One-way) y las medias comparadas por el Teste post-hoc Games-Howell. Los grupos G1 y G3 presentaron los mayores valores medios (11,92 e 14,93MPa respectivamente) con diferencia estadística entre si (p<0.05). Los grupos G2 y G4 presentaron los menores valores (2,35 e 5,50MPa respectivamente) con diferencias estadísticas entre si (p<0.05). Se concluye que los sistemas adhesivos testados actuaron efectivamente sobre el esmalte después de la erosión, no siendo tan eficaz en la dentina, probablemente, debido al over etching

The aim of the present study was to verify the shear bond strength of total and self-etching systems on the surface of enamel and dentine after erosive process. 40 bovine incisors were sectioned and finished until the surfaces got planned in enamel and dentine. On these, erosive process was simulated by using Coke® for 10 days, 4 times by day during 10 min. After, the samples were divided in 4 groups: G1-enamel and G2-dentine, both surfaces were hybridized with total-etching adhesive system (Adper Single Bond II); G3-enamel and G4-dentine were hybridized with self-etching system (Clearfil SE Bond). Resin composite cylinders (Filtek Flow Z350) with 2 mm of height for 0,8 mm of diameter were constructed on these hybridized surfaces and after they were stored in distilled water at 37ºC for 24h. Subsequently, they were submitted to the microshear test in Emic DL 2000 with speed of 1mm/min until failure. The results were submitted to the statistical analysis (ANOVA One-way) and the means were compared by the Test post-hoc Games-Howell. The groups G1 and G3 presented the highest mean values (11.92 and 14.93MPa respectively) however they differed statically itself (p<0.05). By the other hand, the groups G2 and G4 showed the lowest mean values of bond strength (2.35 and 5.50MPa respectively) and they were statistically differents (p<0.05). It can be concluded that both adhesive systems acted effectively on the enamel after erosion process, but on dentin the adhesives were not so efficient due to over etching

In vitro analysis of morphology of human enamel submitted to excessive use of external bleaching agents / Análisis in vitro de la morfología del esmalte humano sometido a un uso excesivo de agentes blanqueadores externos

The aim of this study was to evaluate the effects of external bleaching agents on morphology of human enamel after excessive homemade dental bleaching. 20 intact human third molars were submitted to mesio-distal crosscut and embedded in polystyrene resin. The specimens were submitted to finish and a half of enamel surface of each specimen was covered with cosmetic varnish, meaning control group (G0). The specimens were randomly divided into four groups (n=10): G1 ­ 1 bleaching session by 16 percent carbamide peroxide; G2 ­ 3 bleaching sessions by 16 percent carbamide peroxide; G3 1 bleaching session by 22 percent carbamide peroxide; G4 3 bleaching sessions by 22 percent carbamide peroxide. Each session lasted 8 hours a day, during two weeks, with 45 days of interval between sessions. In this period, the specimens were kept in artificial saliva at 37°C. The specimens were observed by scanning electron microscopy and the results showed depression areas, irregularities, erosion, and enamel prisms exposition, which was more evident in G4. It can be concluded that the excess of bleaching produced many alterations on enamel surface, mainly when was used carbamide peroxide in higher concentration.

El objetivo de este estudio fue evaluar los efectos en la morfología externa del esmalte humano al utilizar excesivamente agentes blanqueadores dentales de uso casero. Se cortaron 20 intactos terceros molares humanos en sentido mesiodistal, luego fueron sumergidas las porciones radiculares en resina de poliestireno. Las muestras fueron pulidas, cubriendo la mitad de la superficie del esmalte con barniz cosmético, representando así al grupo control (G0). Las muestras fueron distribuidas aleatoriamente en cuatro grupos (n=10): G1-Una sesión de blanqueamiento con peróxido de carbamida al 16 por ciento, G2. Tres sesiones de blanqueamiento con peróxido de carbamida al 16 por ciento, G3-Una sesión de blanqueamiento con peróxido de carbamida al 22 por ciento, G4- Tres sesiones de blanqueamiento con peróxido de carbamida al 22 por ciento. Cada sesión tuvo una duración de 8 horas diarias durante dos semanas con 45 días de intervalo entre sesiones. Durante ese periodo las muestras fueron mantenidas en saliva artificial a 37°C. Las muestras fueron observadas al microscopio electrónico de barrido, mostrando aéreas de depresión, irregularidades, erosiones y exposición de prismas del esmalte. Esto fue más evidente en G4. Se puede concluir que el exceso de blanqueamiento producido muchas alteraciones en la superficie del esmalte, sobre todo cuando se utilizó peróxido de carbamida en alta concentración.

Programando o software Imagej para a seleção automática de áreas marcadas por imuno-histoquímica e coradas com o cromógeno dab e contra-coradas pela hematoxilina / Programming Imagej software for automatic selection of immunohistochemistry marked areas stained by dab chromogen and counter-stained by hematoxylin

Introdução: A quantificação dos parâmetros de imunomarcação na análise de imagens de imuno-histoquímica depende da adequada delimitação das regiões marcadas, sendo a seleção destas regiões realizada manualmente ou através de métodos computacionais automáticos ou semi-automáticos. Objetivos: Viabilizar um método de seleção automática de áreas marcadas por imuno-histoquímica por meio do software ImageJ, apresentando a programação envolvida e analisando quantitativamente as imagens. Métodos: Para a aplicação e avaliação da programação proposta neste trabalho foram utilizadas imagens de imuno-histoquímica para localização de alfa-actina de músculo liso (α-SMA) provenientes de estudo de modelo animal experimental de fibrose renal em ratos Wistar machos. Foram capturadas imagens de áreas distintas da região do córtex renal contendo regiões positivas coradas pelo 3,3'-Diaminobenzidina (DAB) em uma lâmina com imunomarcação extensa (n=10) e em outra lâmina com Imunomarcação focal (n=10), provenientes de dois animais. A contra-coloração foi feita com hematoxilina. Resultados: A diferença da extensão da imunomarcação foi qualitativamente evidente entre os dois grupos de imagens. As áreas reveladas pelo DAB nas lâminas dos animais I e II foram selecionadas automaticamente pelo programa, ajustadas pelo operador, e quantificadas, apresentando fração de área ocupada de 23,48 ± 6,52% e de 0,10 ± 0,04% respectivamente, valores expressos em média ± desvio padrão com diferença estatística significativa (p < 0,0001).Conclusões: O software ImageJ mostrou-se adequado para a aplicação da seleção automática de áreas marcadas por imuno-histoquímica, embora a intervenção do operador tenha sido necessária para a correta identificação dos pontos de corte do "threshold", supervisionando a correta delimitação das áreas.

Introduction: The immunostaining quantitative parameters of immunohistochemistry image analysis depend on the proper delimitation of marked regions. The selection of those marked regions is carried out manually, or by computed semi-automatic or automatic methods.Objectives: to carry out a feasible automatic method on selection of immunohistochemistry stained areas applying the Image J software (NIH), presenting the computed program and the quantitative analysis of some images.Methods: For application and evaluation of the proposed program of the study, we used immunehistochemistry images of alpha-smooth muscle actin (α-SMA), a marker of epithelial dedifferentiation, coming from an experimental study of renal fibrosis in Wistar male rats. The images have been captured from non-overlapping regions of the renal cortex, comprising positive 3,3'-Diaminobenzidine (DAB)-stained fields of a strong immunostained slide (N=10, animal I) and another slide with focal immune pattern (N=10, animal II), obtained from two different animals. The slides were counter-stained by Hematoxylin.Results: The difference by immunostaning between the two specimens was qualitatively evident. The areas revealed as DAB-positive in animals I and II slides were automatically selected by the proposed program, visually adjusted by the operator, and finally, quantified, resulting in an occupied area fraction of 23.48 ± 6.52% and 0.10 ± 0.04%, respectively, p<0.0001. Conclusion: The software Image J was able to perform a feasible automatic selection of immunohistochemistry DAB stained areas, although the operator intervention has been necessary to identify the correct threshold cut-off points, supervising if the delimitation of marked areas was precise.

Alterações esqueléticas craniofaciais em portadores de anemia falciforme na cidade de Juiz de Fora / Craniofacial skeletal alterations in sickle cell anemia patients of Juiz de Fora

Este trabalho avaliou as características esqueléticas craniofaciais de 30 indivíduos negros portadores de anemia falciforme, com idade variando entre 20 e 46 anos, cadastrados na Fundação Centro de Hematologia e Hemoterapia de Minas Gerais - Fundação Hemominas, na cidade de Juiz de Fora/MG. Após a obtenção das radiografias cefalométricas em norma lateral de perfil de todos os pacientes, foram realizados os traçados cefalométricos, utilizando alguns ângulos da análise cefalométrica de Steiner e Downs, os quais foram comparados com os valores encontrados por Fortes. As variáveis avaliadas neste trabalho foram os ângulos SNA, SNB, ANB, SND, GoGn.SN, ângulo facial, ângulo de convexidade e ângulo do eixo Y que, após aferidos, foram divididos em tabelas e comparados aos valores padrão preconizados por estes autores e submetidos ao tratamento estatístico, utilizando o teste t-student. O nível de significância adotado foi de 5%. Para avaliação da confiabilidade, foram utilizados os testes t-student para amostras pareadas e de correlação de Pearson. Neste estudo, as variáveis que apresentaram diferença estatisticamente significante entre a média dos valores medidos e o valor padrão de cada variável (p < 0,05) foram SNA, SNB, SND, GoGn.SN e o ângulo de convexidade. As alterações ósseas craniofaciais observadas nestes pacientes foram protrusão da maxila, retrusão da mandíbula, aumento do plano mandibular e perfil facial convexo, com características do padrão esquelético de classe II, sugerindo que a anemia falciforme tem participação nas alterações esqueléticas craniofaciais observadas.

The present study evaluated craniofacial skeletal characteristics of 30 black patients with sickle cell anemia. Their age ranged from 20 to 46 years-old and all of them were enrolled for treatment at Fundação Centro de Hematologia e Hemoterapia de Minas Gerais - Hemominas, in Juiz de Fora. After obtaining all the cephalometrics radiographs of the patients in lateral profile position, cephalometric tracings were done using specificangles of the analysis of Steiner and Downs, and comparing them with values founded by Fortes. Variables assessed in this study were SNA, SNB, ANB, SND, GoGn.SN angle, facial angle, convexity angle and Y axis angle. Angular measurements were them divided into tables and compared to standard values as described by these authors. Statistical analysis was performed using Student's t-test. Significance level was set at 5%. For reliability evaluation, Student's t-test with paired samples and Pearson correlation test were performed. In this study, variables that showed statistically significant difference between the mean of the values obtained and the standard value of each variable (p<0.05) were SNA, SNB, SND, GoGn.SN angle and convexity angle. Craniofacial skeletal alterations founded in these patients were: maxillary protrusion, mandibular retrusion, increase of mandibular plane and convex facial profile. These are characteristics of a Class II skeletal malocclusion, suggesting that sickle cell anemia is involved in the onset of these skeletal alterations.

A reliable positioning device for dorsoventral cephalometric radiography of the rat.

In dental research, dorsoventral cephalometric radiography is often used to assess skull growth and dental movement in rat models. To ensure that images can be reproduced, radiographers must use a cephalostat to maintain the rat's head in a consistent position across imaging sessions. The authors describe a positioning device they designed that connects easily to a standard dental X-ray machine. The device enabled researchers to position rats repeatedly for radiographic imaging with very little variation.

Temporomandibular joint alterations after correction of a unilateral posterior crossbite in a mixed-dentition patient: a computed tomography study.

This article discusses the adaptive alterations of the temporomandibular joints of a boy, aged 8 years 5 months, who underwent correction of a unilateral posterior crossbite. The shape and position of the articular structures, imaged by helicoidal computed tomography at the end of the expansion period and 7 months after treatment, showed a tendency toward condylar centralization and articular symmetry.

Avaliação quantitativa do biofilme dental retido nas ligaduras elásticas, associada ao tempo de permanência na cavidade bucal / Quantitative evaluation of dental biofilm accumulation in elastomeric ligatures in relation to the amount of time within the oral cavity

Objetivo: Determinar a quantidade de biofilme dental retido nasligaduras elásticas, considerando o tempo de permanência nacavidade bucal, e efetuar, nos períodos de uma, duas, três equatro semanas, a comparação do peso inicial e final dessasligaduras. Método: Foram selecionados 20 pacientes comdentição permanente em tratamento na Clínica do Curso deEspecialização em Ortodontia da UFJF, sendo orientados paramanterem seu regime de higiene bucal normal. Após profilaxia,as ligaduras, já pesadas, foram colocadas nos aparelhosortodônticos, sendo utilizadas as correspondentes aossegundos pré-molares. Após a primeira semana, foramremovidas as ligaduras dos pacientes nos elementos 15; após asegunda, nos elementos 25; após a terceira, nos elementos 35;após a quarta, nos elementos 45. Cada ligadura foiarmazenada em uma placa Petri preparada e numerada, sendolevada ao laboratório para pesagem em balança analítica,dentro de um período máximo de três horas. Os resultadosforam submetidos à análise estatística - testes ANOVA e “t” deStudent (P<0.05). Resultados: Em todas as semanas houveaumento de peso, sendo o menor aumento na segundasemana. Observa-se que a diferença entre os pesos iniciais efinais foi estatisticamente significativa para as quatro semanas.Conclusão: A ligadura elastomérica favoreceu a retenção debiofilme dental, e que esse biofilme vai aumentando de acordocom o tempo de permanência na cavidade bucal

Computed tomography evaluation of temporomandibular joint alterations in patients with class II division 1 subdivision malocclusions: condyle-fossa relationship.

Thirty persons with Class II Division 1 subdivision malocclusions, ranging in age from 12 years 8 months to 42 years, underwent computed tomography of the temporomandibular joints. The images obtained from sagittal slices were used to assess the depth of the mandibular fossa, the angulation of the posterior wall of the articular tubercle, the condyle-fossa relationship, and the concentric position of the condyles associated with this malocclusion. Paired Student t tests were applied, and Pearson product moment correlations (r) were determined after measurements on both Class I and Class II sides were obtained. No statistically significant asymmetries were found in the depth of the mandibular fossa, the angulation of the posterior wall of the articular tubercle, or the condyle-fossa relationship. However, a statistically significant (P <.05) anterior positioning of the condyles was observed.

Aplicabilidade de um software para avaliar a morfologia craniofacial em três dimensöes / Applicability of a software to evaluate the craniofacial morphology in three dimensions

O diagnóstico ortodôntico e a escolha terapêutica devem avaliar quais as características do crânio e da face säo determinantes da discrepância maxilomandibular. As mediçöes lineares e angulares nas imagens bidimensionais das telerradiografias laterais e frontais apresentam limitaçöes para a compreensäo dos processos biológicos envolvidos na terapêutica ortopédica na fase do surto de crescimento. O recente desenvolvimento de métodos de avaliaçäo tridimensionais e imagens na área médica, abriu novos horizontes para avaliaçöes morfométricas. Nosso trabalho visa apresentar os recursos proporcionados por um sofware para visualizaçäo, manipulaçäo e análise tridimensional de dados