• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.4
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• pp.361-374
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• 2009

For successful osteogenesis around the implants, interaction between implant surface and surrounding tissue is important. Biomechanical bonding and biochemical bonding are considered to influence the response of adherent cells. But the focus has shifted surface chemistry. The purpose of this study is to evaluate the MC3T3-E1 osteoblast like cell responses of magnesium (Mg) ion implanted titanium surface produced using a plasma source ion implantation method. Commercially pure titanium disc was used as substrates. The discs were prepared to produce four different surface, A: Machine turned surface, B: Mg implanted surface, C: sandblasted surface, D: sandblasted and Mg implanted surface. MC3T3 El osteoblastic like cells were cultured on the disc specimens. Cell adhesion, proliferation, differentiation, and synthesis of extracellular matrix were evaluated. The cell adhesion morphology was evaluated by SEM. RT PCR assay was used for assessment of cell adhesion, proliferation and differentiation. ALP activity was measured for cell differentiation. The results of this study were as follows: 1. SEM showed that cell on Mg ion groups was more proliferative than that of non Mg ion groups. On the machine turned surface, cell showed some degree of contact guidance in aligning with the machining grooves. 2. In RT PCR analysis, osteonectin and c-fos mRNA were more expressed on sandblasted and Mg ion implanted group. 3. ALP activity was not significantly different among all groups. Within the limitations of this study, the following conclusions were drawn: It might indicate Mg ion implanted titanium surface induce better bone response than non Mg ion groups.

• Journal of Korean Neurosurgical Society
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• v.30 no.9
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• pp.1094-1102
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• 2001

Objective : During the trans-condylar or trans-jugular approach for the lesion of cranio-cervical junction(CCJ), its necessary to identify the accurate locations of vertebral artery(VA), internal jugular vein(IJV) and its related lower cranial nerves. These neurovascular structures can also be damaged during the operation for vascular tumor or traumatic aneurysm around extra-jugular foramen, because of their changed locations. To reduce the neurovascular injury at the operation for CCJ, morphometric relationship of its surrounding neurovascular structures based on the tip of the transverse process of atlas(C1 TP), were studied. Materials & Methods : Using 10 adult formalin fixed cadavers, tip of mastoid process(MT) and TPs of atlas and axis were exposed bilaterally after removal of occipital and posterior neck muscles. Using standard caliper, the distances were measured from the C1 TP to the following structures : 1) exit point of VA from C1 transverse foramen, 2) branching point of muscular artery from VA, 3) entry point of VA into posterior atlanto-occipital membrane(AOM), 4) branching point of C-1 nerve. In addition, the distances were measured from the mid-portion of the posterior arch of atlas to the entry point of the VA into AOM and to the exit point of the VA from C1 transverse foramen. After removal of the ventrolateral neck muscles, neurovascular structures were exposed in the extra-jugular foraminal region. Distances were then measured from the C1 TP to the following structures : 1) just extra-jugular foraminal IJV and lower cranial nerves, 2) MT and branching point of facial nerve in parotid gland. In addition, distance between MT and branching point of facial nerve was measured. Results : The VA was located at the mean distance of 12mm(range, 10.5-14mm) from the C1 transverse foramen and entered into the AOM at the mean distance of 24mm(range, 22.8-24.4mm) from the C1 TP. The mean distance from the mid portion of the C1 posterior arch was 20.6mm(range, 19.1-22.3mm) to the entry point of the VA into AOM and 38.4mm(range, 34-42.4mm) to the exit point of the VA from C1 transverse foramen. Muscular artery branched away from the posterior aspect of the transverse portion of VA below the occipital condyle at the mean distance of 22.3mm(range, 15.3-27.5mm) from the C1 TP. The C-1 nerve was identified in all specimens and ran downward through the ventroinferior surface of the transverse segment of VA and branched at the mean distance of 20mm(range, 17.7-20.3mm) from the C1 TP. The IJV was located at the mean distance of 6.7mm(range, 1-13.4mm) ventromedially from the lateral surface of the C1 TP. The XI cranial nerve ran downward on the lateral surface of the IJV at the mean distance of 5mm(range, 3-7.5mm) from the C1 TP. Both IX and X cranial nerves were located in the soft tissue between the medial aspect of the internal carotid artery(ICA) and the medial aspect of the IJV at the mean distance of 15.3mm(range, 13-24mm) and 13.7mm(range, 11-15.4mm) from the C1 TP, respectively. The IX cranial nerve ran downward ventroinferiorly crossing the lateral aspect of the ICA. The X cranial nerve ran downward posteroinferior to the IX cranial nerve and descended posterior to the ICA. The XII cranial nerve was located between the posteroinferior aspect of the IX cranial nerve and the posterior aspect of the ICA at the mean distance of 13.3mm(range, 9-15mm) ventromedially from the C1 TP. The distance between MT and C1 TP was 17.4mm(range, 12.5-23.9mm). The VII cranial nerve branched at the mean distance of 10.2mm(range, 6.8-15.3mm) ventromedially from the MT and at the mean distance of 17.3mm(range, 13-21mm) anterosuperiorly from the C1 TP. Conclusion : This study facilitates an understanding of the microsurgical anatomy of CCJ and may help to reduce the neurovascular injury at the surgery around CCJ.

• Restorative Dentistry and Endodontics
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• v.27 no.4
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• pp.421-431
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• 2002

C-shaped canal configuration is very difficult to treat because that clues about preoperative canal anatomy cannot be ascertained from clinical crown morphology and limited information can be derived from radiographic examination. This study was done to get more informations about the root and canal configuration of C-shape root by 3-dimensionally reconstructing for the purpose of enhancing success rate of endodontic treatment. 30 mandibular molars with C-shaped root were selected. Six photo images from occlusal, apical, mesial, distal, buccal, lingual directions and radiographic view were taken as preoperative ones to compare them with 3-D image. After crown reduction to the level of 1-2mm over pulpal floor was performed, teeth were stored in 5.25% sodium hypochlorite solution for the removal of pulp tissue and debris. They were cleaned under running water, allowed to bench dry and embedded in a self-curing resin. This resin block was serially ground with a microtome (Accutom-50, Struers, Denmark) and the image of each level was recorded by digital camera (FinePix S1-pro, Fuji Co., Japan). The thickness of each section was 0.25mm. Photographs of serial sections through all root canal were digitized using Adobe Photoshop 5.0 and then minimum thickness of open and closed sites were measured (open site is the surface containing occluso-apical groove closed site is oppsite). After dizitization using 3-D Doctor (Able software Corp, USA). 3D reconstruction of the outer surface of tooth and the inner surface of pulp space was made. Canal classsification of C-shaped roots was performed from this 3-D reconstructed image. The results were as follows : 1. Most C-shape rooted teeth showed lingual groove (28/30). 2 According to Vertuccis' calssification, type I, II, III, IV, VII were observed. but also new canal types suck as 2-3-2, 1-2-3-2. 2-3-2-1, 2-3-2-3 were shown. 3 There was little difference in minimum thickness on coronal and apical portions, but open site were thinner than closed site on mid portion. Conclusively, 3D reconstruction method could make the exact configurations of C-shape root possible to be visualized and analyzed from multi-directions. Data from minimum thickness recommend cleaning and shaping be more carefully done on dangerous mid portion.

• Journal of Periodontal and Implant Science
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• v.29 no.1
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• pp.209-231
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• 1999

Even though titanium(Ti) and its alloys are the most used dental implant materials, there are some problems that Ti wears easily and interferes normal osteogenesis due to the metal ions. Ti coated with bioactive ceramics such as hydroxyapatite has also such problems as the exfoliation or resorption of the coated layer, Recent studies on implant materials have been proceeding to improve physical properties of the implant substrate and biocompatibility of the implant surfaces. The purpose of the present study was to examine the physical property and bone tissue compatibility of bioinert nitrides ion plated Ti, Button type specimens(14mm in diameter, 2.32rrun in height) for the abrasion test and cytotoxicity test and thread type implants(3.75mm in diameter, 6mm in length) for the animal experiments were made from Ti(grade 2) and 316LVM stainless steel. Ti specimens were ion plated with TiN, ZrN by the low temperature arc vapor deposition, and the depth profile of the TiN/Ti, ZrN/Ti ion plated surface was examined by Auger Electron Spectroscopy. Three kind of button type specimens .of TiN/Ti, ZrN/Ti and Ti were used for abrasion test, and HEPAlClC7 cells and CCD cells were cultivated for 4 days with the specimens for cytotoxicity test. Thread type implants of TiN/Ti, ZrN/Ti, Ti, 316LVM were implanted on the femur of 6 adult dogs weighing 10kg-13kg. Two dogs were sacrified for histological examination after 45 days and 90 days, and four dogs were sacrified for the removal torque test of the implant') after 90 days. The removal torque force was measured by Autograph (Shimadzu Co., AGS-1000D series, Japan). Abrasion resistance of TiN/Ti was the highest, and that of ZrN/Ti and Ti were followed. The bioinert nitride ion plated Ti had much better abrasion resistance, compared with Ti, In the cytotoxicity test, the number of both cells were increased in all specimens, and there were no significant difference in cytotoxic reaction among all groups (p>0.1), In histological examination, 316LVM showed the soft tissue engagement in interface between the implant and bone, but the other materials after 45 days noted immature new bone formation in the medullary portion along the implant surface, and those after 90 days showed implant support by new bone formation in both the cortical and the medullary portion, The removal torque force of Tilv/Ti showed significantly higher than that of Ti(p(O,05). The difference in removal torque force between TiN/Ti and ZrN/Ti was not significant(p>0.05), and that of 316LVM was lowest among all groups(p<0.05). These results suggest that bioinert nitrides ion plated Ti can resolve the existing problems of Ti and bioactive ceramics, and it may be clinically applicable to human.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.104-115
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• 2018

Purpose: The purpose of this study is to evaluate the image acquisition ability of intraoral scanners by analyzing the comprehensiveness of scanned images from standardized model, and to identify problems of the model. Materials and Methods: Cast models and 3D-printed models were prepared according to international standards set by ISO12836 and ANSI/ADA no. 132, which were then scanned by model scanner and two different intraoral scanners (TRIOS3 and CS3500). The image acquisition performance of the scanners was classified into three grades, and the study was repeated with varying surface conditions of the models. Results: Model scanner produced the most accurate images in all models. Meanwhile, CS3500 showed good image reproducibility for angled structures and TRIOS3 showed good image reproducibility for rounded structures. As for model ingredients, improved plaster model best reproduced scan images regardless of the type of scanner used. When limited to 3D-printed model, powdered surface condition resulted in higher image quality. Conclusion: When scanning structures beyond FOV (field of view) in standardized models (following ISO12836 and ANSI/ADA 132), lack of reference points to help distinguish different faces confuses the scanning and matching process, resulting in inaccurate display of images. These results imply the need to develop a new standard model not confined to simple pattern repetition and symmetric structure.

• Journal of Korean Neurosurgical Society
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• v.56 no.1
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• pp.5-10
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• 2014

Objective : When the pedicle screw insertion technique is failed or not applicable, C7 intralaminar screw insertion method has been used as an alternative or salvage fixation method recently. However, profound understanding of anatomy is required for safe application of the bilaterally crossing laminar screw at C7 in clinic. In this cadaveric study, we evaluated the anatomic feasibility of the bilateral crossing intralaminar screw insertion and especially focused on determination of proper screw entry point. Methods : The C7 vertebrae from 18 adult specimens were studied. Morphometric measurements of the mid-laminar height, the minimum laminar thickness, the maximal screw length, and spino-laminar angle were performed and cross-sectioned vertically at the screw entry point (spino-laminar junction). The sectioned surface was equally divided into 3 parts and maximal thickness and surface area of the parts were measured. All measurements were obtained bilaterally. Results : The mean mid-laminar height was 13.7 mm, mean minimal laminar thickness was 6.6 mm, mean maximal screw length was 24.6 mm, and mean spinolaminar angle was $50.8{\pm}4.7^{\circ}$. Based on the measured laminar thickness, the feasibility of 3.5 mm diameter intralaminar screw application was 83.3% (30 sides laminae out of total 36) when assuming a tolerance of 1 mm on each side. Cross-sectional measurement results showed that the mean maximal thickness of upper, middle, and lower thirds was 5.0 mm, 7.5 mm, and 7.3 mm, respectively, and mean surface area for each part was $21.2mm^2$, $46.8mm^2$, and $34.7mm^2$, respectively. Fourteen (38.9%) sides of laminae would be feasible for 3.5 mm intralaminar screw insertion when upper thirds of C7 spino-laminar junction is the screw entry point. In case of middle and lower thirds of C7 spino-laminar junction, 32 (88.9%) and 28 (77.8%) sides of laminae were feasible for 3.5 mm screw insertion, respectively. Conclusion : The vertical cross-sectioned area of middle thirds at C7 spinolaminar junction was the largest area and 3.5 mm screw can be accommodated with 77.8 % of feasibility when lower thirds were the screw entry point. Thus, selection of middle and lower thirds for each side of screw entry point in spino-laminar junction would be the safest way to place bilateral crossing laminar screw within the entire lamina. This anatomic study result will help surgeons to place the screw safely and accurately.

• Journal of the Korean Arthroscopy Society
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• v.4 no.2
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• pp.154-158
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• 2000

Purpose : The purpose of this study is to demonstrate changes in the orientation ortho glenohumeral ligaments(GHL) in different degrees of abduction and rotation of the normal healthy individuals. Materials and Methods : Saline Magnetic Resonance(MR) arthrography of nine consecutive shoulders of normal healthy adults were checked. At that time, MR images were obtained in three different positions of abduction and external rotation($0^{\circ}C\;and\;0^{\circ},\;45^{\circ}C\;and\;25^{\circ}C,\;90^{\circ}$ and maximum, respectively). From a series of consecutive MRI, three-dimensional images were reconstructed after detecting the location of the middle glenohumeral ligament(MGHL) and the inferior glenohumeral ligament(IGHL) using workstation computer. Results : The shape of the MGHL was taken in double curved, and straight, and finally curved again in three different positions of the shoulder in sequence. On the other hand, the shape of the IGHL was obliquely positioned, and curvilinear, and finally straight and extended at lower part of the anterior surface of the humeral head. Conclusions : At $45^{\circ}$ of abduction and $25^{\circ}$ of external rotation, and at $90^{\circ}$ of abduction and maximal external rotation of the shoulder, the MGHL and the IGHL had the role of the most important static stabilizer of the glenohumeral joint repectively.

• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.85-91
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• 2016

Exosomes are homogenous vesicles of 40-100 nm diameter produced endogenously. Exosomes are generated by inward budding into multi-vesicular bodies (MVB) and then released to extracellular space. Exosomes contain various nucleic acid and protein cargoes from their cells of origin and this endosomal cellular molecules are used for intracellular communication and for both promotion and suppression of immune responses. Recently, they are also considered as delivery vehicle for therapeutic proteins due to their characteristics of stability in body fluids and ability for target uptake. Also, they show less immune reactivity because the isolated exosome harboring therapeutic proteins can be from the same host. White-spotted flower chafer, Protaetia brevitarsis is one of the major insect commercially reared in Korea. There are bacterial and fungal pathogens causing diseases in the beetle, and these diseases incur economic loss to the larva-rearing farms. Due to their endosomal cargoes, exosomes are good candidates in use of disease diagnosis. In this study, we isolated insect exosome from the hemolymph of P. brevitarsis, and verified it by analysis of the exosome-specific surface proteins and RNA.

• Journal of Environmental Science International
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• v.18 no.5
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• pp.589-594
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• 2009

The goals of this study were conducted to investigate the effects of applying liquid aluminum chloride ($AlCl_3$) to rice hulls on pH and soluble reactive P (SRP). A total of 800 broiler chicks (4 treatments $\times$ 4 replicates $\times$ 50 birds) were housed into 16 floor pens in a single house for 5 weeks. The treatments were divided into 4 groups: control, 100 g of liquid $AlCl_3/kg$ of rice hulls, 200 g of liquid $AlCl_3/kg$ of rice hulls, and 300 g of liquid $AlCl_3/kg$ of rice hulls. Liquid $AlCl_3$ was sprayed on the rice hulls surface at a rate of 100 g, 200 g, and 300 g liquid $AlCl_3$ per kg rice hull. pH values and SRP contents were significantly decreased (P<0.05) with the increased liquid $AlCl_3$ levels in comparison with control. However, no significant differences in SRP contents were observed among all treatments at 3 and 4 weeks. Applying 100 g, 200 g, and 300 g liquid $AlCl_3$ to rice hulls reduced SRP contents by 18, 25, and 52% for 5 weeks, respectively, compared with the controls. In conclusion, these results suggest that using liquid $AlCl_3$ on rice hulls should be promising for reducing water contamination and resulted in a reduction in SRP contents, which reduced pH.

• Korean Journal of Acupuncture
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• v.21 no.4
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• pp.43-51
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• 2004

Objectives : In order to ensure safe acupuncture treatment, the quality of the needle tip is essential. But, there have not been so many studies about the quality of the acupuncture needle tip. For this reason we have been already reported about the quality of acupuncture needle tip in Korea using scanning electron microscope(SEM) in 2002, 2003. In order to compare than other society, we investigated the current condition of the tips of the acupuncture needles sold in Europe. Methods : We obtained the needles made by 7 companies, which are sold currently in Europe, and selected 50 pieces out of 100 pieces from each company by randomized methods. And then we observed the tip of each needle using a scanning electron microscope at ${\times}800$ magnification. Results and Discussion : We found that needles had several defects such as scratch marks on the surface, metallic scuff, lumps and irregularities of the needle tips, stubbed or malformed tips, tips of point off-center, peeled off coated tips, same as Korean needles. There was much difference on the quality of needles among the manufacturers, and some needles seem to need thorough quality control. Allowing for the high price, the quality of some needle in Europe generally are better than that of Korean needles. But some Korean needles hold a top position than European ones in quality. We want a good industrial standard to be made in acupuncture manufacturing fields in the near future, because the safety is not less valuable than the efficacy in medicine.