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In order to identify pertinent models of cortical and cancellous bone regeneration, we compared the kinetics and patterns of bone healing in mouse femur using two defect protocols. The first protocol consisted of a 0.9-mm-diameter...
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In order to identify pertinent models of cortical and cancellous bone regeneration, we compared the kinetics and patterns of bone healing in mouse femur using two defect protocols. The first protocol consisted of a 0.9-mm-diameter through-and-through cortical hole drilled in the mid-diaphysis. The second protocol was a 0.9-mm-diameter, 1-mm-deep perforation in the distal epimetaphyseal region, which destroyed part of the growth plate and cancellous bone. Bone healing was analyzed by ex vivo micro-computerized X-ray tomography and histology. In the diaphysis, the cortical gap was bridged with woven bone within 2 weeks. This newly formed bone was rapidly remodeled into compact cortical bone, which showed characteristic parameters of intact cortex 4 weeks after surgery. In the epimetaphysis, bone formation was initiated at the deepest region of the defect and spread slowly toward the cortical gap. In this position, newly formed bone quickly adopted the characteristics of trabecular bone, whereas a thin compact wall was formed at its external border, which reached the density of intact cortical bone but failed to bridge the cortical gap even 13 weeks after surgery. This comparative study indicates that the diaphyseal defect is a model of cortical bone healing and that the epimetaphyseal defect is a model of cancellous bone repair. These models enable experimental genetics studies to investigate the cellular and molecular mechanisms of spontaneous cortical and cancellous bone repair and may be useful for pharmacological studies. Keywords Bone healing - Bone regeneration - Cortical bone - Spongy bone - Mouse bone The authors have stated that they have no conflicts of interest.
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? 2016, Medical Association of Thailand. All rights reserved. ? 2016, Medical Association of Thailand. All rights reserved. Background: Bangkok Biomaterial Center is the only allogenic bone bank in Thailand, supplying the bones to...
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? 2016, Medical Association of Thailand. All rights reserved. ? 2016, Medical Association of Thailand. All rights reserved. Background: Bangkok Biomaterial Center is the only allogenic bone bank in Thailand, supplying the bones to all medical centers. From a report, a certain number of post-operative complications were found. Objective: To compare pre-protocol revision and post-protocol revision success rates and complications associated with the use of allogenic bone grafts relative to perioperative handling and care of allogenic bone. Material and Method: This retrospective comparative study was conducted at the Bangkok Biomaterial Center, Faculty of Medicine Siriraj Hospital, Mahidol University. All registration forms and surgical follow-up reports relating to the use allogenic bones procured from our bone bank between 2005 and 2015 were reviewed. New recommendations for the use of our allogenic bones were established in 2009. Results and complications after allogenic bone transplantation between 2005 and 2008 were compared with results and complications after transplantation to a new protocol between 2009 and 2015. Descriptive analysis and analysis of variance were used to evaluate the data. Results: Data of 825 patients who underwent deep frozen allogenic bone transplantation and 1,541 patients who underwent freeze-dried allogenic bone transplantation were retrospectively reviewed. Overall, the complication rate was reduced from 14.83% in the pre-protocol revision period to 5.15% in the period after the new recommendations for perioperative graft handling were established and implemented. Conclusion: New recommendations for the handling and care of allogenic bone during the perioperative period significantly reduced post-operative complications in patients who received transplantation with deep frozen allogenic bone. The infection rate in patients who received allogenic bone graft was very low. Background: Bangkok Biomaterial Center is the only allogenic bone bank in Thailand, supplying the bones to all medical centers. From a report, a certain number of post-operative complications were found. Objective: To compare pre-protocol revision and post-protocol revision success rates and complications associated with the use of allogenic bone grafts relative to perioperative handling and care of allogenic bone. Material and Method: This retrospective comparative study was conducted at the Bangkok Biomaterial Center, Faculty of Medicine Siriraj Hospital, Mahidol University. All registration forms and surgical follow-up reports relating to the use allogenic bones procured from our bone bank between 2005 and 2015 were reviewed. New recommendations for the use of our allogenic bones were established in 2009. Results and complications after allogenic bone transplantation between 2005 and 2008 were compared with results and complications after transplantation to a new protocol between 2009 and 2015. Descriptive analysis and analysis of variance were used to evaluate the data. Results: Data of 825 patients who underwent deep frozen allogenic bone transplantation and 1,541 patients who underwent freeze-dried allogenic bone transplantation were retrospectively reviewed. Overall, the complication rate was reduced from 14.83% in the pre-protocol revision period to 5.15% in the period after the new recommendations for perioperative graft handling were established and implemented. Conclusion: New recommendations for the handling and care of allogenic bone during the perioperative period significantly reduced post-operative complications in patients who received transplantation with deep frozen allogenic bone. The infection rate in patients who received allogenic bone graft was very low.
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Bone is an integral part of the musculoskeletal system, providing physical scaffoldingas well as an attachment surface for tendons and ligaments to link muscles and bones.Importantly, it is the site of hematopoiesis, which is resp...
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Bone is an integral part of the musculoskeletal system, providing physical scaffoldingas well as an attachment surface for tendons and ligaments to link muscles and bones.Importantly, it is the site of hematopoiesis, which is responsible for the rejuvenation ofblood and immune cell populations essential for healthy physiology (Salhotra et al., 2020).The extraordinary ability of bone to repair and restore itself throughout life is tightlyregulated by the coordinated processes of bone formation/mineralization and boneresorption, which are mediated by two of the most important bone cells, osteoblastsand osteoclasts, respectively. The anabolic and catabolic pathways of these cells, such asBMP-Smad, Wnt/β-catenin, Notch, and Hedgehog, determine and influence their abilityto repair bone. Thus, any change in these pathways can disrupt bone homeostasis and leadto bone disorders such as osteoporosis (Suzuki et al., 2020). As a result, it is critical toinvestigate the expression of molecules in diseased conditions of bone in order tounderstand their role, which may open up new avenues for therapeutic development.Shin et al. Used knockout mice to demonstrate the importance of TLE4 in bonehomeostasis. Tle4 deficiency may impair not only hematopoiesis but also skeletoncalcification via osteoblast function and differentiation by downregulating alkalinephosphatase (ALP), runt-related transcription factor 2 (Runx2), and osteocalcinexpression.
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Background: Autogenous bone grafts obtained by different harvesting techniques behave differently during the process of graft consolidation; the underlying reasons are however not fully understood. One theory is that harvesting te...
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Background: Autogenous bone grafts obtained by different harvesting techniques behave differently during the process of graft consolidation; the underlying reasons are however not fully understood. One theory is that harvesting techniques have an impact on the number and activity of the transplanted cells which contribute to the process of graft consolidation. Materials and Methods: To test this assumption, porcine bone grafts were harvested with four different surgical procedures: bone mill, piezosurgery, bone drilling (bone slurry), and bone scraper. After determining cell viability, the release of molecules affecting bone formation and resorption was assessed by reverse transcription polymerase chain reaction and immunoassay. The mitogenic and osteogenic activity of the conditioned media was evaluated in a bioassay with isolated bone cells. Results: Cell viability and the release of molecules affecting bone formation were higher in samples harvested by bone mill and bone scraper when compared with samples prepared by bone drilling and piezosurgery. The harvesting procedure also affected gene expression, for example, bone mill and bone scraper samples revealed significantly higher expression of growth factors such as bone morphogenetic protein-2 and vascular endothelial growth factor compared with the two other modalities. Receptor activator of nuclear factor kappa B ligand expression was lowest in bone scraper samples. Conclusion: These data can provide a scientific basis to better understand the impact of harvesting techniques on the number and activity of transplanted cells, which might contribute to the therapeutic outcome of the augmentation procedure.
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This study describes the structural features of fibula cortical shell as allowed by serial pQCT scans in 10/10 healthy men and women aged 20-40 years. Indicators of cortical mass (mineral content-BMC-, cross-sectional area CSA-), ...
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This study describes the structural features of fibula cortical shell as allowed by serial pQCT scans in 10/10 healthy men and women aged 20-40 years. Indicators of cortical mass (mineral content-BMC-, cross-sectional area CSA-), mineralization (volumetric BMD, vBMD), design (perimeters, thickness, moments of inertia-MIs-) and strength (Bone Strength Indices, BSIs; polar Strength-Strain Index, pSSI) were determined. All cross-sectional shapes and geometrical or strength indicators suggested a sequence of five different regions along the bone, which would be successively adapted to 1. transmit loads from the articular surface to the cortical shell (near the proximal tibia-fibular joint), 2. favor lateral bending (central part of upper half), 3. resist lateral bending (mid-diaphysis), 4. favor lateral bending again (central part of the lower half), and 5. resist bending/torsion (distal end). Cortical BMC and the cortical/total CSA ratio were higher at the midshaft than at both bone ends (p < 0.001). However, all MIs, BSIs and pSSI values and the endocortical perimeter/cortical CSA ratio (indicator of the mechanostat's ability to re-distribute the available cortical mass) showed a "W-shaped" distribution along the bone, with maximums at the mid-shaft and at both bone's ends (site effect, p < 0.001). The correlation coefficient (r) of the relationship between MIs (y) and cortical vBMD (x) at each bone site ("distribution/quality" curve that describes the efficiency of distribution of the cortical tissue as a function of the local tissue stiffness) was higher at proximal than distal bone regions (p < 0.001). The results from the study suggest that human fibula is primarily adapted to resist bending and torsion rather than compression stresses, and that fibula's bending strength is lower at the center of its proximal and distal halves and higher at the mid-shaft and at both bone's ends. This would favor, proximally, the elastic absorption of energy by the attached muscles that rotate or evert the foot, and distally, the widening of the heel joint and the resistance to excessive lateral bending. Results also suggest that biomechanical control of structural stiffness differs between proximal and distal fibula. (C) 2016 Elsevier Inc. All rights reserved.
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This review provides an overview of various materials used in dentistry and oral and maxillofacial surgeries to replace or repair bone defects. The choice of material depends on factors such as tissue viability, size, shape, and d...
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This review provides an overview of various materials used in dentistry and oral and maxillofacial surgeries to replace or repair bone defects. The choice of material depends on factors such as tissue viability, size, shape, and defect volume. While small bone defects can regenerate naturally, extensive defects or loss or pathological fractures require surgical intervention and the use of substitute bones. Autologous bone, taken from the patient's own body, is the gold standard for bone grafting but has drawbacks such as uncertain prognosis, surgery at the donor site, and limited availability. Other alternatives for medium and small-sized defects include allografts (from human donors), xenografts (from animals), and synthetic materials with osteoconductive properties. Allografts are carefully selected and processed human bone materials, while xenografts are derived from animals and possess similar chemical composition to human bone. Synthetic materials such as ceramics and bioactive glasses are used for small defects but may lack osteoinductivity and moldability. Calcium-phosphate-based ceramics, particularly hydroxyapatite, are extensively studied and commonly used due to their compositional similarity to natural bone. Additional components, such as growth factors, autogenous bone, and therapeutic elements, can be incorporated into synthetic or xenogeneic scaffolds to enhance their osteogenic properties. This review aims to provide a comprehensive analysis of grafting materials in dentistry, discussing their properties, advantages, and disadvantages. It also highlights the challenges of analyzing in vivo and clinical studies to select the most suitable option for specific situations.
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In this article, we summarize the developments in the mathematical modeling of the mechanics of bone and related biological phenomena. We will devote special attention to the results of the last 10–15?years, although we will cove...
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In this article, we summarize the developments in the mathematical modeling of the mechanics of bone and related biological phenomena. We will devote special attention to the results of the last 10–15?years, although we will cover some relevant classical work to better frame the more recent researches. We will propose a division of the literature based on the main aim of the model (mechanical/biomathematical) and the type of biological phenomena considered (stimulus, growth, cell population dynamics). Finally, we will suggest some possible directions for future investigations.
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The targeting and delivery of therapeutic and diagnostic agents to bone tissue presents both a challenge and opportunity. Osteoporosis, Paget's disease, cancer, and bone metastases are all skeletal diseases whose treatment would b...
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The targeting and delivery of therapeutic and diagnostic agents to bone tissue presents both a challenge and opportunity. Osteoporosis, Paget's disease, cancer, and bone metastases are all skeletal diseases whose treatment would benefit from new targeted therapeutic strategies. Osteoporosis, in particular, is a very prevalent disease, affecting over one in three women and one in five men in Canada alone with the cost to the healthcare system estimated at over $2.3 billion in 2010. Bone tissue is often considered a rigid structure when in reality there is a process of continuous remodeling that takes place via complex endocrine-regulated cell signaling pathways in addition to the signaling pathways unique to bone tissue. It is these specific boneremodeling processes that provide unique targeting opportunities but also present a number of challenges.
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Purpose The radionuclide bone scan is the cornerstone of skeletal nuclear medicine imaging. Bone scintigraphy is a highly sensitive diagnostic nuclear medicine imaging technique that uses a radiotracer to evaluate the distribution...
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Purpose The radionuclide bone scan is the cornerstone of skeletal nuclear medicine imaging. Bone scintigraphy is a highly sensitive diagnostic nuclear medicine imaging technique that uses a radiotracer to evaluate the distribution of active bone formation in the skeleton related to malignant and benign disease, as well as physiological processes. Methods The European Association of Nuclear Medicine (EANM) has written and approved these guidelines to promote the use of nuclear medicine procedures of high quality. Conclusion The present guidelines offer assistance to nuclear medicine practitioners in optimizing the diagnostic procedure and interpreting bone scintigraphy. These guidelines describe the protocols that are currently accepted and used routinely, but do not include all existing procedures. They should therefore not be taken as exclusive of other nuclear medicine modalities that can be used to obtain comparable results. It is important to remember that the resources and facilities available for patient care may vary.
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Background: Bone may be basically exceedingly vascular, living, continually evolving mineralized connective tissue. It will be amazing to its hardness, flexibility furthermore regenerative capacity, as well as its characteristic g...
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Background: Bone may be basically exceedingly vascular, living, continually evolving mineralized connective tissue. It will be amazing to its hardness, flexibility furthermore regenerative capacity, as well as its characteristic growth mechanisms. Objectives: histological study to substantiate that bone salioprotein when applied locally on generated bone defect healing in rat tibia, it was very effectiveness. Material and method: In this study forty-eight albino male rats, weighting (300-400) gram, aged (6-8) months, will make utilized under control states for temperature, drinking and food utilization. The animals will subject for an intra-bony defect in medial side of tibiae bone, in control group (12 rats) the bone defect dealt with absorbable haemostatic sponge, same time the experimental group (12 rats) will be dealt with local application of 30 μl bone salioprotein settled toward absorbable haemostatic sponge. The rats were sacrificed during 7, 14, also 28 days after surgery (four rats to every time for each group). Results: Histological discoveries shown that bone defect dealt with local application of bone salioprptein demonstrates a promptly osteoid tissue formation with high cell number for osteoblast, osteocyte furthermore osteoclast. Conclusion: Those goals that bone salioprotein improve bone healing and increase osteogenic capacity; this proof done our information need aid pledging for could reasonably be expected clinical management done future.
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