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Direct Current and Bone Growth
Published in Andrew A. Marino, Modern Bioelectricity, 2020
Other reports also indicate that electrical polarity is not a fundamental factor in electrical osteogenesis (76–79). Two parallel os teo tomies, 0.4 inches apart, were made normal to the sagittal suture and posterior to the coronal suture in the calvaria of rabbits (76). The defects were stimulated 15 hours/day, 6 days/week, for 3 weeks using platinum electrodes (anterior anode). The amount of bone present in the defects at sacrifice was determined by measuring the optical density of high-resolution radiographs of the excised calvaria. For reasons that were not explained, the control anode exhibited less healing than the more posteriorly located control cathode (4% vs. 35%). When the defects were stimulated using 10 μA DC, the amount of bone present at the electrodes was increased by roughly the same proportion at the anode and the cathode (4% increased to 8%, compared to 35% increased to 65%) (76).
Stress and strain propagation on infant skull from impact loads during falls: a finite element analysis
Published in International Biomechanics, 2020
F.J. Burgos-Flórez, Diego Alexander Garzón-Alvarado
Through the use of the finite element method (FEM), several studies have focused on modeling and computationally simulating the effect of various types of skull impacts on the relative motion and stress and strain distributions of adult brains (Zhang et al. 2001; Yang et al. 2014; Torkestani et al. 2015; Hasnun et al. 2015). However, these studies have not taken into account the intrinsic differences of infant skulls when it comes to experiencing a fall and impact on the encephalic structures. Among these characteristics, the continuous geometric change caused by brain expansion during the first two years of life generates an initial bulge in the parietal and frontal bones, which is not present in the adult skull. In addition, the presence of soft tissues such as sutures and fontanels, primary sites of mechanical deformation and bone formation processes during the first two years of postnatal life, and a single layer of cortical bone less than 2 mm thick in each flat bone of the calvaria, make the child’s skull one of less mechanical resistance when compared to that of an adult. Therefore, a specific biomechanical analysis for the infant’s skull that considers its particularities is necessary to generate a greater understanding of TBE during childhood.