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Spongy Bone (spongy + bone)

Distribution by Scientific Domains

Medical Sciences	80%

Selected Abstracts

Alveolar Ridge Regeneration with Equine Spongy Bone: A Clinical, Histological, and Immunohistochemical Case Series

CLINICAL IMPLANT DENTISTRY AND RELATED RESEARCH, Issue 2 2009
Danilo Alessio Di Stefano DDS
ABSTRACT Background: In the case of localized ridge atrophy, a ridge augmentation procedure, with the use of bone substitutes and barrier membranes, may then be necessary. Purpose: The aim of the present study was a clinical, histological, and immunohistochemical evaluation of an equine spongy bone in alveolar ridge augmentation procedures. Materials and Methods: Five patients showing horizontal mandibular ridge defects participated in this study. A ridge augmentation was performed through an onlay apposition of equine bone covered by a titanium-reinforced membrane. After 6 months of healing, five bone cores from nonaugmented sites (control) and five from augmented sites (test) were retrieved. Results: In test sites, no postoperative complications occurred. Horizontal bone width increased from ,4 to ,7 mm. In control sites, the newly formed bone represented 33%, and in test sites, 35% of the total area. The mean value of the microvessel density was 25.6 +/, 3.425 per mm2 in controls, while 33.3 +/, 2.5 vessels per mm2 in the test sites were found (p < .05). Both groups showed a high intensity (++) of vascular endothelial growth factor expression in the newly formed bone, while a low intensity (+) was found in the mature bone. Conclusion: Equine bone appeared to be biocompatible and to be associated with new vessel ingrowth. Within the limits of the small sample size, the present study indicated that equine bone could be used in mandibular ridge augmentations. [source]

Influence of Bone Tissue Density and Elasticity on Ultrasound Propagation: An In Vitro Study

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 12 2000
Francesca de Terlizzi
Abstract Ultrasound (US) waves are mechanical vibrations that are applied to a material,bone tissue,in order to study its properties, that is, density, elasticity, and structure. In this study we evaluated in which way density and elasticity of the spongy bone influenced the transmission of 1.25 MHz US pulses. Twelve cylindrical specimens (diameter, 8 mm; height, 5 mm) excised from phalanxes of pig were decalcified with 0.5 M EDTA for different times (0, 2, and 5 days). During these periods, the samples underwent the following investigations: US transmission, density, and elasticity measurements. To assess the homogeneity of decalcification, the cross-sections of some samples were microradiographed. A detailed analysis of the US signal received was performed using velocity, Fourier analysis, and some parameters typical of signal processing technique. A good correlation was found between US velocity and density (r2 = 0.70); a lower correlation was found between velocity and elasticity (r2 = 0.59). If density and elasticity are considered simultaneously, the correlation with the US velocity improves significantly (r2 = 0.84). Fourier analysis enabled us to observe a shift of the main frequency toward lower values as the decalcification process advanced. We also observed that in the regressions weighted for density, US velocity correlated poorly with elasticity (r2 = 0.16), whereas signal processing parameters maintain a good correlation with elasticity (ultrasound peak amplitude [UPA], r2 = 0.48; slope, r2 = 0.62). In this study, it has been observed that when using a signal processing technique to analyze US pulses, it is possible to identify some parameters that are related in different ways to density and to elastic properties of bone. Our results show the potentiality of US technique to separate information on bone density and elasticity that X-ray-based densitometric methods do not provide. [source]

Differential diagnosis of mastoid hypocellularity in human skeletal remains

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009
Stefan Flohr
Abstract Mastoid hypocellularity is frequently used as an indicator of chronic otits media in paleopathological investigations. The condition can be caused by a poor development of air cells during infancy and early childhood (primary hypocellularity) or by obliteration of air cells with bone during later life (secondary hypocellularity). We performed a macroscopic, radiographic, and microscopic study of pneumatization patterns in 151 mastoid processes of individuals from an early-medieval cemetery in Germany, with emphasis on the architecture of the nonpneumatized portion of hypocellular mastoid processes. Two types of primary mastoid hypocellularity were distinguished. The first was characterized by a poorly defined boundary between the pneumatized portion and the nonpneumatized portion and a trabecular thickening in the spongy bone of the latter. The second showed a well-defined boundary between the pneumatized portion and the nonpneumatized portion and normal spongy bone architecture in the latter. The key feature for the diagnosis of secondary hypocellularity was the recognition of the walls of former air cells. Our observations closely match the histopathological findings by Wittmaack (Wittmaack: Über die normale und die pathologische Pneumatisation des Schläfenbeins. Jena: Gustav Fischer [1918]), who developed a concept of the normal pneumatization process of the temporal bone and the pathogenesis of aberrant pneumatization. We agree with Wittmaack's view that two types of primary mastoid hypocellularity can be distinguished morphologically. Regarding the pathogenesis of these types, we, however, conclude that Wittmaack's concept needs to be revised and updated. Further studies are required to establish the relationship between morphological findings in cases of mastoid hypocellularity and the health status of individuals. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source]

Alveolar Ridge Regeneration with Equine Spongy Bone: A Clinical, Histological, and Immunohistochemical Case Series

Human osteoclast formation and activity on an equine spongy bone substitute

CLINICAL ORAL IMPLANTS RESEARCH, Issue 1 2009
Vittoria Perrotti
Abstract Objectives: The aim of the present study was to evaluate the in vitro formation and activity of human osteoclasts (OCLs) generated on a new type of xenograft for bone substitution, an equine spongy bone. Material and methods: Peripheral blood mononuclear cells from healthy volunteers were used to generate OCLs in vitro in the presence of macrophage colony stimulating factor (M-CSF) and receptor activator of NF-,B ligand (RANKL) on bovine bone slices (positive control) and equine spongy bone. Morphological and biochemical methods were used to assess OCLs formation and activity. Results: Cells generated after 21 days of culture on equine spongy bone showed similar morphology to those on the positive control and displayed typical OCL markers and features, indicating that this material supported OCL formation. Moreover, these cells were functionally active on equine spongy bone with statistically significant differences compared with the control in the release of tartrate-resistant acid phosphatase (TRAcP5b) at days 14 and 21 of culture. With regard to the resorption, on equine bone, OCLs formed smaller discontinuous island-like lacunae rather than the typical lobulated, tracking resorption lacunae observed on the control. Conclusions: This study enables clinicians to tailor the usage of equine spongy bone and presents a model, which can be applied to the preclinical assessment of bone substitute material's resorbability and resorption rates. [source]