The purpose of the present study was to evaluate the incidence of dental anomalies in Brazilian patients with Down syndrome. A sample with 49 panoramic x-rays of syndromic patients aged 3 to 33 years (22 male and 27 female) was used. The characteristics of dental anomalies were observed in the panoramic radiographs in both the primary and permanent dentition, according to the ICD (International Classification of Diseases). The corresponding tables and percentile analysis were elaborated. There was a high incidence of syndromic patients with different types of anomalies, such as taurodontism (50%), proven anodontia (20.2%), suspected anodontia (10.7%), conic teeth (8.3%) and impacted teeth (5.9%). In conclusion, patients with Down syndrome presented a high incidence of dental anomalies and, in most cases, the same individual presented more than one dental anomaly.

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ObjectiveThis study has two aims: 1) to evaluate the apical transportation of the Wizard CD Plus and ProTaper Universal after preparation of simulated root canals; 2) to compare, with Adobe Photoshop, the ability of a new software (Regeemy) in superposing and subtracting images. Material and MethodsTwenty five simulated root canals in acrylic-resin blocks (with 20º curvature) underwent cone beam computed tomography before and after preparation with the rotary systems (70 kVp, 4 mA, 10 s and with the 8×8 cm FoV selection). Canals were prepared up to F2 (ProTaper) and 24.04 (Wizard CD Plus) instruments and the working length was established to 15 mm. The tomographic images were imported into iCAT Vision software and CorelDraw for standardization. The superposition of pre- and post-instrumentation images from both systems was performed using Regeemy and Adobe Photoshop. The apical transportation was measured in millimetres using Image J. Five acrylic resin blocks were used to validate the superposition achieved by the software. Student's t-test for independent samples was used to evaluate the apical transportation achieved by the rotary systems using each software individually. Student's t-test for paired samples was used to compare the ability of each software in superposing and subtracting images from one rotary system per time. ResultsThe values obtained with Regeemy and Adobe Photoshop were similar to rotary systems (P>0.05). ProTaper Universal and Wizard CD Plus promoted similar apical transportation regardless of the software used for image's superposition and subtraction (P>0.05). ConclusionWizard CD Plus and ProTaper Universal promoted little apical transportation. Regeemy consists in a feasible software to superpose and subtract images and appears to be an alternative to Adobe Photoshop.

Objective: to verify the accuracy of cone beam computedtomography (CBCT) for measuring dentin thicknessin the danger zone of mandibular molars in order to validatethis method to be used as a clinical auxiliary. Materialsand method: dentin thickness of the distal wall ofmesial canals was measured at 2 mm of furcation areain ten mandibular molars before and after preparation ofcervical and middle thirds. CBCT (0.25 mm voxel size)and stereomicroscopy images were acquired twice foreach sample. CBCT axial images and stereomicroscopeimages were evaluated by a calibrated examiner. Statisticalanalysis was performed using Mann-Whitney testin order to investigate whether CBCT images providedtrusted values. Results: mean values of initial (1.23 versus1.24 mm) and final measurements (0.88 versus 0.87mm) obtained with, respectively, CBCT and stereomicroscopemethods did not show statistical differences(P > 0.5). Conclusion: CBCT images provide high accuracyfor measuring dentin thickness in the danger zoneof mandibular molars.Keywords: Cone beam computed tomography. Endodontics.Root canal preparation.

Neste estudo in vitro, avaliou-se a progressão da perda mineral causada pela aplicação de ácido clorídrico a 18% em esmalte proximal de dentes pré-molares humanos, utilizando a técnica de subtração digital de imagens, por meio da comparação dos valores de densidade óptica nas ROI com e sem aplicação ácida. Foram utilizados um aparelho ra-diográfico Gendex 765DC e o sistema Visualix Gx-S HDI para radiografia digital direta. Os resultados foram obtidos utilizando três tempos de exposição aos raios X (0,025, 0,050, 0,100s) com e sem a interposição de um simulador para tecidos moles. Variação no tempo de exposição aos raios X e uso de simulador não tem influência sobre os valores de densidade óptica das imagens radiográficas subtraídas (p>0,05). Os valores de densidade óptica diferiram entre as ROI com e sem aplicação ácida (p=0,00). A variação na densidade óptica das ROI possibilitou avaliar a progressão da perda mineral em esmalte proximal utilizando imagens radiográficas subtraídas; a técnica de subtração digital da imagem radiográfica permitiu a visualização da progressão da perda mineral em esmalte proximal.

Introduction: 3D printing is experiencing significant growth in the teaching and learning process. This study aims to present a 3D printed skull model for preclinical intraoral radiographic practice.Materials and Methods: Two 3D printed mannequins were created. One mannequin used an STL file of a skull that was edited using two 3D modelling software (Meshmixer and Netfabb). The second mannequin was designed directly from a patient's segmented CBCT data and then converted into an STL file. Both mannequins were printed using fused deposition modelling (FDM) technology and polylactic acid (PLA) filament; teeth for the second mannequin were also printed using digital light processing (DLP). The printed skull bones were attached, the mandible was articulated to the articular fossa of the temporal bone, and the teeth were inserted into the alveoli. Intraoral radiographs of both mannequins were taken using a digital sensor (RVG 5100, Carestream).Results: Both 3D printed mannequins showed satisfactory radiographic appearance, allowing geometric representation of each intraoral radiographic projection, regardless of STL file origin. Anatomical structures, such as the periodontal ligament space, zygomatic process of the maxilla and intermaxillary suture, were represented. The

Objetivo: avaliar caninos inclusos em tomografias computadorizadas multidetectores (TCMD) realizadas noHospital Universitário de Santa Maria. Materiais e método: foi realizado um estudo observacional transversalcom imagens de um banco de dados de TCMD de baixa dose de radiação, solicitadas por indicações clínicasodontológicas. Os exames em formato digital imaging and communications in medicine foram avaliados porum examinador treinado, no software Weasis Medical Viewer. A avaliação dos exames compreendeu a observação das seguintes características: impactação do canino (uni ou bilateral), localização do canino (maxilaou mandíbula), localização da coroa do canino (vestibular ou lingual/palatal), eixo de erupção, espessura dofolículo pericoronário, presença de lesões associadas, presença de reabsorção nos dentes adjacentes e presença de agenesias dentárias ou de supranumerários. Os resultados foram avaliados de maneira descritiva, por meio de prevalência dos achados. Resultados: foram encontrados 21 caninos inclusos em 837 tomografiasavaliadas (1,9%). Foi observado um predomínio de indivíduos do sexo feminino (71,4%), e a retenção do canino foi mais frequente na maxila (71,4%) e com impactação unilateral (61,9%). Quatro caninos apresentaramfolículo pericoronário, com espessura maior que 2 mm; 19% dos exames apresentaram reabsorção radicular externa em algum incisivo lateral. Apenas um canino apresentava lesão associada, sugerindo escleroseóssea. Além dos caninos inclusos, foi possível avaliar alterações relacionadas às demais regiões e estruturasdentomaxilofaciais. Conclusão: apesar da amostra limitada de imagens, o presente estudo demonstrou a aplicabilidade clínica da TCMD com protocolo de baixa dose de radiação, para a avaliação dos caninos inclusose características relacionadas a esses dentes, bem como de dentes e regiões adjacentes.

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