Direct measurement of tibial cortical bone surface area

The permeability of the blood in the artificial cancellous are affected by certain morphological aspects that include pore diameter, pore size, porosity and the bone surface area. In this study, computational fluid dynamics method is used to study the fluid flow through the cancellous structure. Result of the present work show that geometries with the same porosity and overall volume can have different permeability due to the differences in bone surface area. The hexahedron geometry has the highest permeability under stimulated blood flow conditions, where the cylindrical geometry has the lowest. Linear relationship is found between permeability and the two physical properties, bone surface area and the pore size.

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FEM analysis of a new miniplate: stress distribution on the plate, screws and the bone

European Journal of Dentistry ◽

10.1055/s-0039-1698925 ◽

2012 ◽

Vol 06 (01) ◽

pp. 009-015 ◽

Cited By ~ 5

Author(s):

Didem Nalbantgil ◽

Murat Tozlu ◽

Fulya Ozdemir ◽

Mehmet Oguz Oztoprak ◽

Tulin Arun

Keyword(s):

Finite Element ◽

Cortical Bone ◽

Three Dimensional ◽

Fem Analysis ◽

Force Distribution ◽

Bone Surface ◽

Dimensional Model ◽

Three Dimensional Model ◽

Dimensional Finite Element ◽

Three Dimensional Finite Element

ABSTRACTObjectives: Non-homogeneous force distribution along the miniplates and the screws is an unsolved question for skeletal anchorage in orthodontics. To overcome this issue, a miniplate structure was designed featuring spikes placed on the surface facing the cortical bone. The aim of this study was to examine and compare the force distribution of the newly designed plate-screw systems with the conventional one.Methods: A model of bone surface with 1.5 mm cortical thickness, along with the two newly designed miniplates and a standard miniplate-screw were simulated on the three-dimensional model. 200 g experimental force was applied to the tip of the miniplates and the consequential effects on the screws and cortical bone was evaluated using three-dimensional finite element method.Results: As a result of this finite element study, remarkably lower stresses were observed on the screws and the cortical bone around the screws with the newly designed miniplate when compared with the conventional one.Conclusion: The newly designed miniplate that has spikes was found effective in reducing the stress on and around the screws and the force was distributed more equivalently. (Eur J Dent 2012;6:9-15)

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Pattern of Uptake of Americium-241 by the Rat Skeleton and its Subsequent Redistribution and Retention: Implications for Human Dosimetry and Toxicology

Human Toxicology ◽

10.1177/096032718300200109 ◽

1983 ◽

Vol 2 (1) ◽

pp. 101-120 ◽

Cited By ~ 17

Author(s):

N.D. Priest ◽

G. Howells ◽

D. Green ◽

J.W. Haines

Keyword(s):

Bone Marrow ◽

Bone Resorption ◽

Cortical Bone ◽

Female Rat ◽

Half Time ◽

Bone Surface ◽

Similar Model ◽

Phagocytic Cells ◽

Biological Half Time

The distribution and retention of intravenously injected 241Am in the skeleton of the female rat has been investigated using autoradiographic and radiochemical techniques. The studies were designed to assess the dosimetric and toxicologic implications of an 241Am intake by man. They showed that in the rat approximately one third of the intravenously injected 241Am was deposited in the skeleton where it appeared to be retained with a long biological half-time. The studies also showed: 1241Am is initially deposited onto all types of bone surface including endosteal surfaces, periosteal surfaces and those of the vascular canals within cortical bone, but seems to be preferentially deposited onto those that are resorbing, 2 Bone accretion results in the burial of surface deposits of 241Am, 3 Bone resorption causes the removal of 241 Am from surfaces, 4 Resorbed 241Am is retained by phagocytic cells (probably macrophages) in the bone marrow, 5 The transfer of 241Am from the phagocytic cells in the marrow to adjacent bone surfaces seems to occur, (local recycling). 6 The possibility that some of the 241Am removed from the bone surfaces enters the blood and is redeposited in bone, (systemic recycling) cannot be dismissed These results show that 241Am deposition and redistribution in bone shares many characteristics with other 'bone surface-seeking radionuclides' typified by 239Pu. Consequently, it is suggested that a similar model to that used to calculate annual limits of intake for 239Pu in man would be suitable for the calculation of corresponding values for the 241Am isotopes.

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Comparative Evaluation of Cortical Bone Anatomy of Mandibular Buccal Shelf for Mini Implant Placement in Different Facial Divergence: A Cone Beam Computed Tomography Study

The Journal of Indian Orthodontic Society ◽

10.1177/0301574220932265 ◽

2020 ◽

Vol 54 (4) ◽

pp. 325-331

Author(s):

Kalyani Trivedi ◽

Bharvi K Jani ◽

Sagar Hirani ◽

Mansi V Radia

Keyword(s):

Computed Tomography ◽

Cortical Bone ◽

Cone Beam Computed Tomography ◽

Cone Beam ◽

Bone Surface ◽

Bone Thickness ◽

Second Molar ◽

Cortical Bone Thickness ◽

Implant Placement ◽

Alveolar Crest

Aim: The purpose of this study was to use measurements from cone beam computed tomography scans to quantify the cortical bone thickness of mandibular buccal shelf region and preferable site for buccal shelf implant placement in 10 hyperdivergent and 10 hypodivergent patients. Method: 20 cone beam computed tomographies were equally divided based on divergence. 6 sites were examined: mesial of first molar (6M), middle of first molar (6Mi), interdental between the first and second molar (Id), mesial of second molar (7M), middle of second molar (7Mi), and distal of second molar (7D). The study quantified the mandibular buccal shelf relative to its angle of slope, the cortical bone thickness measured perpendicular to the bone surface, the amount of cortical bone 30° angle to the bone surface. The cortical bone thickness was measured perpendicular and at a 30° angle at 3, 5, and 7 mm from the alveolar crest. Result: Significant change is seen at the buccal shelf slope at 6M ( P = .001) and further increase in this angle till 7D ( P = .003). Mean amount of cortical bone for hyperdivergent group at 7D is 4.77 ± 0.68 mm and for hypodivergent group is 3.86 ± 0.70 mm. Statistically significant differences were noted at insertion site at 90° and 30° for both groups at 3, 5, and 7 mm from the alveolar crest. Conclusion: Preferable site for buccal shelf implant placement is distal to the mandibular second molar. The maximum amount of cortical bone is found distal to the second molar 7 mm vertically from alveolar crest when the buccal shelf implant is placed at 30° angulation for hyperdivergent group.

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