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Detection of periimplant fenestration and dehiscence with the use of two scan modes and the smallest voxel sizes of a cone-beam computed tomography device

2013-01-01T00:00:00Z

Título: Detection of periimplant fenestration and dehiscence with the use of two scan modes and the smallest voxel sizes of a cone-beam computed tomography device Autor(es): Vaz, Sergio Lins de Azevedo; Vasconcelos, Karla de Faria; Neves, Frederico Sampaio; Melo, Saulo Leonardo Sousa; Campos, Paulo Sérgio Flores; Haiter Neto, Francisco Abstract: Objective To assess the accuracy of cone-beam computed tomography (CBCT) in periimplant fenestration and dehiscence detection, and to determine the effects of 2 voxel sizes and scan modes. Study Design. One hundred titanium implants were placed in bovine ribs in which periimplant fenestration and dehiscence were simulated. CBCT images were acquired with the use of 3 protocols of the i-CAT NG unit: A) 0.2 mm voxel size half-scan (180°); B) 0.2 mm voxel size full-scan (360°); and C) 0.12 mm voxel size full scan (360°). Receiver operating characteristic curves and diagnostic values were obtained. The Az values were compared with the use of analysis of variance. Results The Az value for dehiscence in protocol A was significantly lower than those of B or C (P < .01). They did not statistically differ for fenestration (P > .05).Conclusions Protocol B yielded the highest values. The voxel sizes did not affect fenestration and dehiscence detection, and for dehiscence full-scan performed better than half-scan. Tipo: Artigo de Periódico

Radicular dens invaginatus in a mandibular premolar: cone-beam computed tomography findings of a rare anomaly

2013-01-01T00:00:00Z

Título: Radicular dens invaginatus in a mandibular premolar: cone-beam computed tomography findings of a rare anomaly Autor(es): Neves, Frederico Sampaio; Pontual, Andréa dos Anjos; Campos, Paulo Sérgio Flores; Frazão, Marco Antônio Gomes; Almeida, Solange Maria de; Ramos Perez, Flávia Maria de Moraes Abstract: Dens invaginatus is a rare developmental anomaly and its etiology remains controversial. Radicular dens invaginatus is an unusual dental anomaly. The aims of this paper are to report the radiographic and tomographic findings of a case of radicular dens invaginatus and to discuss the relevant features associated with this dental anomaly. A 16-year-old female was referred to a private oral radiology clinic for orthodontic evaluation. Radiographically, a morphological alteration to the root portion of the right mandibular first premolar and the presence of a discrete radiolucent periapical lesion were observed. The diagnosis was only elucidated after cone-beam computed tomography (CBCT). The CBCT images revealed enlargement of the root, and a dilated invagination with limited enamel that had its open site along the lateral portion of the root without evidence of buccal and lingual expansion. The diagnosis of radicular dens invaginatus was then established. Tipo: Artigo de Periódico

Density of mast cells and microvessels in minor salivary gland tumors

2013-01-01T00:00:00Z

Título: Density of mast cells and microvessels in minor salivary gland tumors Autor(es): Vidal, Manuela Torres Andion; Araújo, Iguaracyra Barreto de Oliveira; Gurgel, Clarissa Araújo Silva; Pereira, Francisco De Assis Caldas; Vilas Bôas, Deise Souza; Ramos, Eduardo Antônio Gonçalves; Agra, Ivan Marcelo Gonçalves; Gonçalves, Ivan Marcelo; Freitas, Valéria Souza; Santos, Jean Nunes dos Abstract: The aim of this study was to investigate the density of mast cells and microvessels in minor salivary gland tumors. Forty-one cases of minor salivary gland tumors (pleomorphic adenoma, n = 10; adenoid cystic carcinoma, n = 11; mucoepidermoid carcinoma, n = 10; and polymorphous low-grade adenocarcinoma) were investigated using immunohistochemistry for mast cell tryptase and von-Willebrand factor. Density of mast cells was higher in mucoepidermoid carcinoma; however, no differences in the number of these cells were observed between the different types of tumors (p > 0.05). The number of mast cells was higher in periparenchymal areas in all tumors, but the difference was not significant (p > 0.05). Mucoepidermoid carcinoma showed the largest number of periparenchymal mast cells, whereas pleomorphic adenomas showed the smallest number of intraparenchymal mast cells (p > 0.05). The highest microvessel density was observed in mucoepidermoid carcinomas, being this difference statistically significant when mucoepidermoid carcinoma was compared to pleomorphic adenoma (p = 0.0034) and polymorphous low-grade adenocarcinoma (p = 0.004). Microvessel density was significantly higher in adenoid cystic carcinoma when compared to pleomorphic adenoma (p = 0.0406) and polymorphous low-grade adenocarcinoma (p = 0.0123). Comparison of mast cells and microvessel densities showed no significant difference between tumors. A quantitative difference in mast cells and microvessels was observed, particularly in mucoepidermoid carcinoma, a finding supporting the aggressive behavior of malignant salivary gland tumors without myoepithelial differentiation. Further studies are needed to determine the role of mast cells in angiogenesis, as well as in the development and biological behavior of these tumors. Tipo: Artigo de Periódico

Evaluation of the Effects of Buccal–Palatal Bone Width on the Incidence and Height of the Interproximal Papilla Between Adjacent Implants in Esthetic Areas

2013-01-01T00:00:00Z

Título: Evaluation of the Effects of Buccal–Palatal Bone Width on the Incidence and Height of the Interproximal Papilla Between Adjacent Implants in Esthetic Areas Autor(es): Siqueira Jr., Sergio; Pimentel, Suzana P.; Alves, Renato V.; Sendyk, Wilson; Cury, Patricia Ramos Abstract: Background: The presence of interproximal papilla depends on the distance between the contact point to the bone crest, as well as the mesio-distal distance between implants or between implants and teeth. The aim of this study is to evaluate the effects of buccal–palatal bone width on the presence of the interproximal papilla between adjacent implants in esthetic areas of the mouth. Methods: The presence or absence of the gingival papilla, distance from the base of the interproximal contact to the tip of the gingival papilla (black space), distance from the base of the interproximal contact to the alveolar crest (vertical distance), alveolar bone width (bone width) between adjacent implants as well as the spacing between the implants (horizontal distance), and soft-tissue biotype were assessed in 29 interimplant areas in the upper incisor, canine, and premolar regions of 18 patients. Results: The papilla was always present when vertical distance was ≤5 mm (P ≤0.04) and frequently present when the horizontal distance was ≥4 mm (P = 0.04). The black space was smaller when the vertical distance was ≤5 mm (P ≤0.04) and when the horizontal distance was ≥4 mm (P = 0.76). Bone width and soft-tissue biotype did not influence the incidence of gingival papilla (P ≥0.41) and black space (P ≥0.15). Conclusion: Within the limits of this study, it can be concluded that bone width and tissue biotype do not have an effect on the incidence and height of papilla between adjacent implants in esthetic areas, and the incidence was greater when vertical distance was ≤5 mm or when horizontal distance was ≥4 mm. Tipo: Artigo de Periódico