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Skull – Occipito-Frontal 30-Degree Cranial (Reverse Towne’s)
Published in A Stewart Whitley, Charles Sloane, Gail Jefferson, Ken Holmes, Craig Anderson, Clark's Pocket Handbook for Radiographers, 2016
A Stewart Whitley, Charles Sloane, Gail Jefferson, Ken Holmes, Craig Anderson
The sella turcica of the sphenoid bone is projected within the foramen magnum.The image must include all of the occipital bone, and the posterior parts of the parietal bone and lambdoid suture should be clearly visualised.The skull should not be rotated.
Angio-osteogenic capacity of octacalcium phosphate co-precipitated with copper gluconate in rat calvaria critical-sized defect
Published in Science and Technology of Advanced Materials, 2022
Shinki Koyama, Ryo Hamai, Yukari Shiwaku, Tsuyoshi Kurobane, Kaori Tsuchiya, Tetsu Takahashi, Osamu Suzuki
Wistar rats (12 weeks old, male, Japan SLC, Inc., Hamamatsu, Japan) were used to examine the vascularization and bone regeneration behaviors induced by the OCP/Gel, low-Cu-OCP/Gel, and Cu/Gel in bone defects. Anesthetization was performed via the inhalation of isoflurane by rats and subsequent injection of mixed anesthetic agents consisting of medetomidine (Nippon Zenyaku Kogyo Co., Ltd., Fukushima, Japan), midazolam (Sandoz K.K., Tokyo, Japan), and butorphanol (Meiji Seika Pharma Co., Ltd., Tokyo, Japan) into their peritoneal cavity. The dose amount of medetomidine, midazolam, and butorphanol was 0.38 µg/g, 2.0 µg/g, and 2.5 µg/g to the weight of rats, respectively. The skin and periosteum were sectioned along the bilateral line and middle of the forehead. A critical-sized defect, which does not repair spontaneously, with a diameter of 9 mm [40] was created on the line sagittal suture between the lambdoid suture and coronal suture. A trephine drill was used to create defects. The OCP/Gel (n = 5) and low-Cu-OCP/Gel (n = 5) composites were implanted into the defects. The Cu/Gel sponges (n = 5) were also implanted as control groups. After implantation, the ablated periosteum and skin were repositioned and sutured.
Mutual chemical effect of autograft and octacalcium phosphate implantation on enhancing intramembranous bone regeneration
Published in Science and Technology of Advanced Materials, 2021
Hisashi Ozaki, Ryo Hamai, Yukari Shiwaku, Susumu Sakai, Kaori Tsuchiya, Osamu Suzuki
Twelve weeks old Wistar male rats (Japan SLC, Inc. Hamamatsu, Japan) were used for animal experiments to examine the bone formation behavior of the calvarial defects treated with OCP granules, autogenous bone granules, and a mixture of the two. All procedures for animal handling and treatment in this study were reviewed and approved by the Animal Research Committee of Tohoku University (approval number 2018DnA-036). The protocol conformed to all principles of laboratory animal care and national laws. Rats were anesthetized by inhalation of isoflurane, followed by the intraperitoneal injection of three types of mixed anesthetic agents (0.38 µg/g of medetomidine, 2.0 µg/g of midazolam, and 2.5 µg/g of butorphanol relative to the weight of the rat). The skin was sectioned along the bilateral line and the middle of the forehead, and the periosteum of the calvaria was ablated. A full-thickness standardized defect with a diameter of 9 mm was created using a trephine drill during the injection of saline, and bone fragments on the dura mater of the brain were collected. The created defect was located on the line sagittal suture between the lambdoid suture and coronal suture. The harvested calvarial bone (autogenous bone) was cut into granules of approximately 1 mm × 1 mm. 10.0 mg OCP granules (OCP group, n = 5), 42.7 mg autogenous bone granules (Auto group, n = 5), and a mixture of 5.0 mg OCP and 21.4 mg autogenous bone granules (OCP + Auto group, n = 5) were implanted into the defect. Defects without implantation were also created as a negative control (n = 5) using the same method as for the implantation of the granules. The ablated periosteum and skin were repositioned and sutured after the implantation of the granules or creation of the defect without implantation. At 2, 4, and 8 weeks of implantation, the calvarial tissue with and without implantation of the granules collected from the sacrificed rats were fixed with 10% formalin solution for 1 day.
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
A finite element model of the skull of a four week-old infant was developed and employed for simulating free fall from low heights. Two types of impacts were simulated, each considering different fall heights and different degrees of ossification in the suture and fontanels. The first one was an occipito-parietal impact on the lambdoid suture and the second one, a lateral impact on the right parietal bone. Impacts were simulated after a free fall from 30 cm and 50 cm in height. Six different cases of the degree of ossification of sutures and fontanels were established as follows. A first case considered unossified sutures and fontanels, using the material properties defined for sutures in Table 1. A second case considered fully ossified sutures and fontanels. In this case, the mechanical properties of these tissues were assumed to be the same as those of flat bones. Thus, Young’s modulus was equal to 200 MPa, density equal to 2150 , and Poisson’s modulus equal to 0.22. Cases three to six considered the premature fusion of the sutures. Four different types of craniosynostosis were considered: sagittal, metopic, right lambdoid, and right coronal craniosynostosis. Therefore, the suture level of ossification was modeled by changing the material properties of the sutures according to each type of craniosynostosis. Skull morphology remained constant since we wanted to compare how the suture’s level of ossification influenced stress and strain propagation in the different tissues forming the infant’s head. Figure 1 provides an overall view of the effects of premature suture fusion on the overall shape of the infant skull.” Two types of impact, two fall heights and six cases of ossification of suture and fontanels, resulted in a total of 24 simulations performed, each one with a simulation time of 8 ms with time steps of 1E-007 seconds. Each simulation took into account non-linear effects in the deformation. Two types of contact between the rigid surface and the skull were defined: A normal contact and a tangential contact in which a coefficient of friction equal to 0.2 was established. The gravity was equal to 9.8 and, from the equation , where g is the gravity and h the height of the fall, initial skull velocity at impact time was set at 2.42487 and 3.130, corresponding to free falls from 30 and 50 cm in height, respectively. These data were previously found in the dynamic model. The impact occurred against a rigid surface with properties similar to those of ceramic material (E = 150 GPa, υ = 0.17), as shown in Figure 4. As in the dynamic model, boundary conditions were defined as no strain, and no external forces were applied to the model before impact.