Application of chitosan in dentistry—a review
J. Belinha, R.M. Natal Jorge, J.C. Reis Campos, Mário A.P. Vaz, João Manuel, R.S. Tavares in Biodental Engineering V, 2019
The structural scaffold of our body is the skeleton, and the bones that constitute it are key elements for locomotion, antigravity support, life-sustaining functions, and protection of viscera (Graber, Vanarsdall, Vig, & Huang, 2017; Walsh, 2018). Bone tissue is a specialized form of highly vascularized connective tissue which main components are collagen and calcium phosphate (Q. Li, Ma, & Gao, 2015). Bone is divided in cortical and trabecular tissues. The first is a hard and outer layer that surrounds the marrow space, while the latter resembles a honeycomb-like network of interspersed plates and rods, occupying a larger surface area (Clarke, 2008; Walsh, 2018). The cellular component of the bone includes osteoblasts, osteoclasts and osteocytes, each one of them with specific functions. Osteoblasts are responsible for forming bone by synthesizing the organic matrix, which is mainly type I collagen, and for giving bone resistance and tensile forces. On the other hand, osteoclasts, that derive from the monocyte/macrophage cell line, locally degrade the bone matrix during the resorption process. Osteocytes are localized between the bone matrix and are terminally differentiated osteoblasts that convert mechanical loading into biomechanical stimulus (Feng & McDonald, 2011).
Pathogenesis: Molecular mechanisms of osteoporosis
Peter V. Giannoudis, Thomas A. Einhorn in Surgical and Medical Treatment of Osteoporosis, 2020
The bone tissue displays important functions in vertebrates that include the protection of vital organs and hematopoietic marrow, the support of muscles, and the storage and release of vital ions such as calcium. The bone tissue is a type of mesenchymal tissue. In the human body, there are two types of bone tissue: cortical and trabecular. The cortical bone represents 80% of the skeleton, while the trabecular bone the remaining 20%. The cortical tissue is found predominantly in the long bones. However, trabecular tissue is found in the central part of the epiphysis of long bones. Trabecular tissue outweighs the flat bones of the pelvis and the vertebrae and is coated in its surface of a cortical tissue layer. The major types of bone tissue cells are osteoblasts, osteoclasts, and osteocytes. We also distinguish organic and inorganic phases in bones. The organic phase includes type I collagen (90%), proteoglycans, and non-collagenous proteins. The organic phase constitutes one-third of bone mass. The inorganic phase comprises calcium salts in the form of hydroxyapatite crystals and constitutes two-thirds of bone mass (19).
Osteoporosis
Maria A. Fiatarone Singh, John Sutton Chair in Exercise, Nutrition, and the Older Woman, 2000
Bones are primarily made up of calcium, protein in the form of collagen fibers, and other minerals. There are two different types of bone tissue: trabecular bone and cortical bone. Approximately 80% of the skeleton is cortical bone, with the remaining 20% being made up of trabecular bone. All bones have both types of tissue; however, some bones are predominantly trabecular while others have greater amounts of cortical bone. Trabecular bone is lightweight and spongy in appearance because it is filled with red marrow and fat and is found in the vertebrae of the spine, the top part of the hips, the breast bone, and at the ends of the long bones in the arms and legs. Cortical bone, which is denser but thinner, surrounds trabecular bone and is found to a greater degree in the long bones of the arms and legs.
Effect of the medial collateral ligament and the lateral ulnar collateral ligament injury on elbow stability: a finite element analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Fang Wang, Shuoqi Jia, Mingxin Li, Kui Pan, Jianguo Zhang, Yubo Fan
The shape, structure and tissue parameters of elbow joint are complex. The premise of establishing elbow model was that the geometric shape and material property parameters of the model were consistent with the anatomical structure of human elbow. Bone tissue is a kind of biphasic composite material, which could be divided into inorganic material and collagen amorphous matrix. Most literatures regarded bone tissue as isotropic elastic material for biomechanical analysis (Bendjaballah et al. 1997). Buchler et al. (Büchler et al. 2002) defined the material properties of shoulder joint cartilage as hyperelastic material. A study (Quapp and Weiss 1998) constructed a FE model of MCL, which was regarded as hyperelastic material. Bone was defined as isotropic homogeneous elastic material in this study. Ligaments and articular cartilages were modelled as hyperelastic material to better reflect the nonlinear characteristics of soft tissues. The Neo Hooke model (Büchler et al. 2002) was selected to describe the hyperelastic materials by strain energy potential instead of elastic modulus and poisson's ratio. The Neo Hooke function was as follows:
Simulation of the mechanical behavior of osteons using artificial gravity devices in microgravity
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Hao Zhang, Hai-Ying Liu, Chun-Qiu Zhang, Zhen-Zhong Liu, Wei Wang
After a long period of evolution and natural selection, the structure and functions of the human body have almost perfectly adapted to the Earth’s environment (Darwin 1963). Bone tissue plays a critical role in supporting the human body. The osteocyte network in bone tissue senses the external load and other information from the environment to regulate bone reconstruction activities. This process achieves the optimal state of bone mineral density corresponding to the requirements of the external environment. Bone metabolism and mechanical signal transduction are closely related to the microenvironment of osteocytes. Fluid in the LCS is the carrier of material exchange between osteocytes and the blood (Price et al. 2011). Bone is generally composed of compact bone distributed in the outer layer of bone and cancellous bone in the inner layer of bone. Dense bone is composed of the outer and inner circumferential lamellae and the osteons between them. In contrast, cancellous bone is composed of intertwined trabeculae (Shi et al. 2016).
Concurrent consideration of cortical and cancellous bone within continuum bone remodelling
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2021
Ina Schmidt, Areti Papastavrou, Paul Steinmann
This work aims to simulate bone density changes of cancellous and cortical bone as well as their interplay based on a continuum bone remodelling approach. Unlike spongy bone, the bone fibrils of cortical bone are densely packed, which is why this lamellar structure is also called compact bone. Remodelling of cortical bone can occur along the endosteal and periosteal surface as well as within the channels. The surface area per unit volume is considerably reduced compared to cancellous bone and therefore remodelling requires more time with less change in density. In order to adapt to the load case, the main mechanism considered here is the adjustment of the microstructural density. Whereas a change in bone geometry will not be considered, the simulation of bone adjustments in the endosteal area such as trabecularisation and thinning of the inner compact bone in old age is made possible.
Related Knowledge Centers
- Biomineralization
- Osteocyte
- Skeleton
- White Blood Cell
- Connective Tissue
- Osteoblast
- Red Blood Cell
- Hard Tissue
- Honeycomb
- Matrix