Resumo Objetivou-se avaliar a influência do uso excessivo de uma placa de fósforo fotoestimulável (PSP) na densidade, ruído e contraste das radiografias. Foram adquiridas radiografias de um bloco de acrílico com uma PSP do sistema intraoral Express para avaliar a densidade e o ruído da imagem. Inicialmente, cinco imagens foram obtidas e exportadas (primeiro grupo). Após 400 exposições aos raios X e escaneamentos, outras cinco imagens foram obtidas e exportadas (segundo grupo). O mesmo procedimento foi feito após 800 (terceiro grupo), 1200 (quarto grupo), 1600 (quinto grupo) e 2000 aquisições (sexto grupo), resultando em 30 imagens a serem avaliadas. A média e o desvio padrão dos valores de cinza foram calculados para as imagens usando o software ImageJ. Para análise de contraste, foram adquiridas radiografias de uma escala de alumínio com uma nova PSP seguindo os mesmos intervalos de aquisição. A porcentagem de variação do contraste foi calculada. Outras duas PSP sem uso prévio foram utilizadas para avaliar a reprodutibilidade dos métodos. A comparação dos resultados entre os grupos de aquisição foi realizada pela Análise de Variância one-way (α=0,05). O Coeficiente de Correlação Intraclasse (ICC) avaliou a reprodutibilidade dos receptores. O ruído da imagem não diferiu entre os grupos (p>0,05). Houve um leve aumento na densidade após 400 aquisições e uma pequena diferença no contraste para todos os grupos de aquisição sem padrão de aumento ou diminuição (p<0,05). O ICC mostrou excelente confiabilidade para os métodos. Portanto, o uso excessivo da PSP afetou levemente a densidade e o contraste radiográfico. Objetivouse Objetivou se (PSP Inicialmente primeiro grupo. grupo . 40 escaneamentos segundo 80 terceiro grupo, , 120 quarto 160 quinto 200 sexto 3 avaliadas ImageJ calculada métodos oneway one way α=0,05. α005 α α=0,05 0 05 (α=0,05) (ICC receptores p>0,05. p005 p p>0,05 (p>0,05) p<0,05. p<0,05 (p<0,05) Portanto radiográfico 4 8 12 16 20 α00 α=0,0 (α=0,05 p00 p>0,0 (p>0,05 p<0,0 (p<0,05 1 2 α0 α=0, (α=0,0 p0 p>0, (p>0,0 p<0, (p<0,0 α=0 (α=0, p>0 (p>0, p<0 (p<0, α= (α=0 p> (p>0 p< (p<0 (α= (p> (p< (α (p

Abstract The study aimed to assess the influence of excessive use of a photostimulable phosphor plate (PSP) on the density, image noise, and contrast of radiographs. For that, radiographs of an acrylic block were acquired with a PSP of the Express intraoral system to assess the density and image noise. Initially, five images were obtained and exported (first group). After 400 exposures to X-rays and scannings of PSP, other five images were obtained and exported (second group). The same procedure was done after 800 (third group), 1200 (fourth group), 1600 (fifth group), and 2000 acquisitions (sixth group), resulting in 30 images to be evaluated. The mean and standard deviation of the gray values were calculated for the images using the ImageJ software. For contrast analysis, radiographs of an aluminum step-wedge were acquired with a new PSP following the same acquisition intervals. The percentage of contrast variation was calculated. Another two unused PSP receptors were employed to evaluate the method’s reproducibility. The comparison of the results among the acquisition groups was performed with one-way Analysis of Variance (α=0.05). Intraclass Correlation Coefficient (ICC) assessed the reproducibility of the receptors. Image noise did not differ among the groups (p>0.05). There was a slight increase in density after 400 acquisitions and a slight difference in contrast for all acquisition groups without a pattern of increase or decrease (p<0.05). ICC showed excellent reliability for the methods. Therefore, excessive PSP use slightly affected the radiograph’s density and contrast. (PSP that Initially first group. group . group) 40 Xrays X rays second 80 third group, , 120 fourth 160 fifth 200 sixth 3 evaluated software analysis stepwedge step wedge intervals methods method s oneway one way α=0.05. α005 α α=0.05 0 05 (α=0.05) (ICC p>0.05. p005 p p>0.05 (p>0.05) p<0.05. p<0.05 (p<0.05) Therefore radiograph 4 8 12 16 20 α00 α=0.0 (α=0.05 p00 p>0.0 (p>0.05 p<0.0 (p<0.05 1 2 α0 α=0. (α=0.0 p0 p>0. (p>0.0 p<0. (p<0.0 α=0 (α=0. p>0 (p>0. p<0 (p<0. α= (α=0 p> (p>0 p< (p<0 (α= (p> (p< (α (p

Abstract This study aimed to assess the microstructure, chemical composition, and image quality of different photostimulable phosphor plates (PSP). Four PSP systems, Express®, Digora®, VistaScan®, and Apixia,® were assessed. Five radiographs of a homogeneous acrylic phantom were obtained with the PSP of each system, to acquire a total of 20 images. The images were objectively evaluated for uniformity using mean grey and standard deviation (SD) of their grey values. PSP receptors were analyzed using scanning electron microscopy (SEM) to determine the thickness of the granule layer and the size of the granules. The chemical composition of the PSP receptors was analyzed using total reflection X-ray fluorescence (TXRF). VistaScan showed more uniform and higher density images than the other tested systems (p < 0.05), as well as the lowest SD of grey values (p < 0.05). Regarding the microstructure of the receptors, Digora and VistaScan had thicker granule layers than Express and Apixia, and VistaScan had smaller granules than Digora and Express (p < 0.05). Fourteen chemical elements were detected in the receptors, with barium being the element with the highest concentration in all PSP systems. The microstructure, chemical composition, and image quality varied among all four PSP receptors studied. VistaScan receptors showed the smallest variation in granule size, one of the thickest granule layers, and the most uniform and least noisy images.

Abstract: Evaluating factors that may influence the nose dimensions and, therefore, contribute to the singularity of a person, is important for obtaining a precise facial reconstruction (FR) in forensic anthropology. Thus, the aim in this study was to evaluate the influence of sex, skeletal class, and facial type on nose dimensions of Brazilian individuals using cone-beam computed tomography (CBCT) scans. CBCT images of 54 males and 67 females were classified according to skeletal class (class I, II, or III) and facial type (brachycephalic, dolichocephalic and mesocephalic). Linear and angular measurements of the nose were performed using the CS 3D Imaging software. The measurements obtained for males and females were compared by one-way ANOVA. Two-way ANOVA was used to compare the measurements in the different skeletal classes and facial types. Significance level was set at 5%. All linear measurements were greater in males (p < 0.05); the angular measurements, however, did not differ between sexes (p > 0.05). Linear and angular measurements of class III males were significantly different from the other classes; the same was observed for the angular measurements in females (p < 0.05). Regarding facial types, some linear measurements were significantly greater in dolichocephalics males (p < 0.05). For females, there was no influence of facial type (p > 0.05), except for the nasal convexity angle. Nose dimensions differed in specific points among different skeletal classes and facial types, and there was sexual dimorphism in all linear nose dimensions. This information may be applicable for nose reconstructions, allowing more reliable FR.

Resumo O presente estudo utilizou imagens de microtomografia computadorizada (MicroCT) para avaliar a prevalência, número e localização de ramificações apicais (RAs) dos canais radiculares de diferentes grupos dentários em uma população brasileira. Trezentos e sessenta e sete dentes humanos extraídos (totalizando 475 raízes) foram escaneados em um aparelho de MicroCT, com uma resolução espacial de 19,6 µm. As imagens foram analisadas em consenso por dois avaliadores, e uma análise descritiva foi realizada para verificar a prevalência, número e localização de RAs em cada grupo dentário. O teste Qui-quadrado foi utilizado para comparar a prevalência de RAs em diferentes tipos de raízes e a análise de variância (ANOVA - um critério) comparou o número de RAs em 1 mm, 2 mm e 3 mm apicais da raiz. O nível de significância foi estabelecido em 5% (α=0,05). As RAs estavam presentes em 253 (53,3%) das 475 raízes avaliadas. Foram detectadas 607 RAs com a maioria (530) localizada a 1 e 2 milímetros do forame principal. A mais alta prevalência de RAs foi observada nos caninos superiores (65%); pré-molares superiores - unirradiculares (83,3%), raiz vestibular (80%) e raiz palatina (73,3%); pré-molares inferiores (64,2%); raiz mésio-vestibular dos molares superiores (76,6%); e raiz mesial dos molares inferiores (66,6%). Na população brasileira, a maioria dos RAs está localizada em 1 e 2 mm apicais da raiz, com maior prevalência nos dentes posteriores e nos caninos superiores. Esses achados sugerem atenção adicional ao planejar um tratamento endodôntico, bem como adoção de estratégias para uma limpeza e obturação efetiva da região apical dos dentes.

Abstract The present study used microcomputed tomography (micro-CT) images to assess the prevalence, number, and location of apical ramifications (ARs) in the root canals of different dental groups in a Brazilian population. Three hundred and sixty-seven extracted human teeth, totaling 475 roots, were scanned by micro-CT at 19.6 µm spatial resolution. The obtained images were evaluated by two observers in consensus, and a descriptive analysis was performed to verify the prevalence, number, and location of ARs in each dental group. Chi-square test was used to compare the prevalence of ARs in different types of roots, and one-way analysis of variance compared the number of ARs in the apical 1 mm, 2 mm, and 3 mm of the root. Significance level was established at 5% (α=0.05). ARs were present in 253 (53.3%) of the 475 roots evaluated. A total of 607 ARs were detected, with the vast majority (530) located at one and two millimeters from the main foramen. The highest prevalence of ARs was observed in maxillary canines (65%); maxillary premolars - single-rooted (83.3%), buccal root (80%), and palatine root (73.3%); mandibular premolars (64.2%); mesiobuccal root of maxillary molars (76.6%); and mesial root of mandibular molars (66.6%). For the Brazilian population, most of the ARs are located in the apical 1 and 2 mm of the root, with greater prevalence in the posterior teeth and maxillary canines. These findings suggest the need for additional attention while planning endodontic treatments, including strategies to effectively clean and fill the apical region.