• The korean journal of orthodontics
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• v.22 no.2 s.37
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• pp.389-412
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• 1992

Along with form and function relationship of craniofacial growth comes a concern for the masticatory muscles with postnormal occlusion. It is the aim of this study to grope the certain differences upon the electromyographic activities of the masticatory muscles between normal occlusion and class II malocclusion during the varieties of oral functions. 26 persons of normal occlusion whose mean age were 18.9-25.6 years and another 26 persons of class II malocclusion whose mean age were 19.0-28.9 years served for this study. The electromyographic recordings processed by $Medelec^{\circledR}$ MS 25 EMG apparatus were taken from the anterior and posterior temporal, and anterior and posterior masseter muscles of both sides, and suprahyoid muscles as well. Analyses of the data toward such specific activities as mandibular rest, maximal biting, chewing gums and swallowing peanuts turned out the following summary and conclusions. 1. The maximal mean amplitude of the posterior temporalis showed significant augmentation in class II malocclusion, however the anterior temporalis, posterior masseter, and suprahyoid muscles manifested meaningful diminutions. 2. Stronger posterior temporalis and weaker anterior masseter and suprahyoid muscles were arranged in maximal biting with parameters of maximal mean amplitude. 3. The anterior temporalis of working side expressed smaller maximal mean amplitude in class II malocclusion. Significant swelling in duration were shown at anterior and posterior temporalis of working side, and posterior temporalis of balancing side in class II malocclusion, and marked reduction at anterior masseter of balancing side and posterior masseter of working side as well. The lessened latency were expressed at anterior masseter of working side, and anterior and posterior masseter of balancing side. Class II malocclusion group had significant prolongation of silent period duration. Mean silent period duration of 10.75 msec in normal occlusion and 24.37 msec in class II malocclusion were calculated. 4. Significant augmentations of maximal mean amplitude while swallowing peanuts were yielded at right anterior temporalis and posterior temporalis of both sides, however left anterior masseter and right posterior masseter showed diminution. No significant differences in duration showed at every muscle examined in class II malocclusion group.5. Weaker masseter and stronger temporalis were suggested as characteristics of class II malocclusion.

• Herbal Formula Science
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• v.11 no.2
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• pp.173-184
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• 2003

Objectives: This study investigates the effects of Salviae miltiorrhizae Radix, Carthami Flos on Brain ischemia of the rats induced from the Occlusion of Lt. Common Carotid Artery. Methods: I observed effects using light microscopes and examined tissue of parietal lobe and hippocampus and VEGF-immunoreactive cells. Results: A small number of VEGF-immunoreactive cells are observed in the control group. VEGF-immunoreactive cells in Salviae miltiorrhizae Radix-administered group were slightly increased compared with control group. VEGF-immunoreactive cells in Carthami Flos-administered group were significantly increased compared with control group. Neurons of parietal lobe and pyramidal cells of hippocampus in the control group were greatly damaged.(neuronal densitity, form of dendrite and axon) On the other hand, neurons of parietal lobe and pyramidal cells of hippocampus in Salviae miltiorrhizae Radix-administered group were less damaged. Neurons of parietal lobe and pyramidal cells of hippocampus in Carthami Flos-administered group were significantly less damaged compared with control group. Conclusion : Salviae miltiorrhizae Radix, Carthami Flos can effect on stimulating angiogenesis and reducinging the damage of neurons in the rats induced from the Occlusion of Lt. Common Carotid Artery.

• The Journal of the Korea Contents Association
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• v.17 no.1
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• pp.740-749
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• 2017

The epigraphy is a text or a picture engraved on metal or stone. One of advantages of rubbing of ancient inscription has been used in epigraphic field is simple. But the rubbing is not an optimal method in viewpoints of resolution and noise to decode the inscribed characters. In this study, we proposed a new research method that increases the possibility of a reading by reflecting the 3D characteristics of the engraved letters. The proposed techniques apply 3D scanning technology to obtain three-dimensional and high quality data of each of the letters in the epigraphy and use Ambient Occlusion visualization techniques to express the shade according to the 3D form of the letters. Research result enhances the readability of the letters that removed the damaged and worn information from the letters information of surface. This research contributes to narrow the scope of a particular letter and read to the controversial letters on the Pohang Jungsoengri Silla Stone Monument(Korea's national treasure number 318).

• Journal of Korean Neurosurgical Society
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• v.30 no.12
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• pp.1406-1416
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• 2001

Objective : The goal of this study was to evaluate the effect of Gamma Knife radiosurgery(GKS) on cerebral arteriovenous malformation(AVM) and the factors associated with complete occlusion. Patients and Methods : A total of 369 radiosurgical procedures for 336 patients with cerebral AVMs were performed between December 1988 and June 2001. Three hundreds and twenty-four cases of 293 patients who were treated with GKS procedures from May 1992 to December 2000 were analyzed. Various clinical and radiologic parameters were evaluated. Results : The total obliteration rate for the cases with satisfactory radiological follow-up(more than 2 years) after GKS was 79.3%. In multivariate analysis, maximal diameter, angiographic form of AVM nidus, and number of draining veins significantly influenced the result of radiosurgery. In addition, marginal radiation dose, Spetzler-Martin grade, and flow pattern of AVM nidi also partly influenced the radiosurgical outcome. Conclusion : GKS on cerebral AVM is considered as an effective treatment modality. The risk of hemorrhage seems to decrease within the latency interval between GKS and complete occlusion of nidus. Along with the size, topography, or radiosurgical parameters of AVMs, it is necessary to consider the angioarchitectural and hemodynamic aspects to select proper candidates for radiosurgery.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.2
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• pp.286-318
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• 1992

The objective of preventive dentistry is the maintenance of a healthy dentition for the life of a patient. Unfortunately, if an individual has not received the benefit of a comprehensive program of preventive dentistry and has finally reached the edentulous state, as a consequence, he receives a set of complete denture. Dentures are mechanical devices and subject to the principles of mechanics. In some cases, the general health and nutritional status of the patient are felt to be the causative factors. But, the most important thing in residual ridge resorption is felt to be caused by the unequal distribution of functional forces. This study was to analyze mandibular stresses of complete denture occlusion by three dimensional finite element method. The results were as follows ; 1. As deformation and stress distribution of the complete denture of the mandible were concentrated on the upper lingual side of the mandible, alveolar ridge resorption of the mandible occurred from lingual side to labio-buccal side. 2. Analyzing by three dimensional F. E. M., the mandible is a very effective form for tolerating stress and deformation biomechanically. 3. According to the concentration of stress distibution in the upper buccal side of the lower posteriors, buccal shelf area must be a primary stress bearing area in the lower complete denture. 4. Lower complete denture moved horizontally to the balancing side under lateral occlusal force. 5. Bilateral balanced occlusion should be constructed in the complete denture for denture stability, especially in the protrusive movement. 6. Physical property of the denture base material was as important for stress distribution in the denture base as or even more than that in the mandible. 7. Impression technique is very important because of most of stress was concentrated between them due to close contact of the mandible and the denture base.

• Journal of Periodontal and Implant Science
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• v.44 no.5
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• pp.227-234
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• 2014

Purpose: Dentin hypersensitivity is a potential threat to oral health. Laser irradiation may provide reliable and reproducible treatment but remains controversial. The present study aimed to evaluate the effects of $CO_2$ or erbium-doped yttrium aluminium garnet (Er:YAG) laser therapy, and to assess mineral content. Methods: Eighteen human single-rooted teeth affected with advanced periodontitis were obtained. Buccal and lingual surfaces were planed to form 36 specimens. Ethylenediaminetetraacetic acid gel (24%) was applied to remove the smear layer and simulate hypersensitive teeth. The experimental groups were: group 1, control (no irradiation); group 2, $CO_2$ laser (repetitive pulsed mode, 2 W, $2.7J/cm^2$); and group 3, Er:YAG laser (slight contact mode, 40 mJ/pulse and 10 Hz). To evaluate dentinal tubule occlusion, six specimens per group (2-mm thickness) were prepared and observed using scanning electron microscopy (SEM) for calculation of the occlusion percentage. To evaluate the mineral content, six specimens per group (0.6-mm thickness) were used, and then the levels of Ca, K, Mg, Na, and P were measured by inductively coupled plasma-atomic emission spectrometry. In addition, the surface temperature of the specimens during laser irradiation was analyzed by a thermograph. Results: The SEM photomicrographs indicated melted areas around exposed dentinal tubules and a significantly greater percentage of tubular occlusion in the $CO_2$ and Er:YAG laser groups than the control, and in the Er:YAG group than the $CO_2$ laser group. In addition, no significant differences were noted among the experimental groups for the mineral elements analyzed. The $CO_2$ laser group showed an evident thermal effect compared to the Er:YAG group. Conclusions: $CO_2$ and Er:YAG laser are effective in treating dentin hypersensitivity and reducing its symptoms. However, the Er:YAG laser has a more significant effect; thus, it may constitute a useful conditioning item. Furthermore, neither $CO_2$ nor Er:YAG lasers affected the compositional structure of the mineral content.

• The Korean Journal of Physiology and Pharmacology
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• v.10 no.2
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• pp.85-94
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• 2006

A splanchic artery occlusion for 90 min followed by reperfusion of the mesenteric circulation resulted in a severe form of circulatory shock, characterized by endothelial dysfunction, severe hypotension, marked intestinal tissue injury, and a high mortality rate. The effect of defibrotide, a complex of single-stranded polydeoxyribonucleotides having antithrombotic effect, was investigated in a model of splanchnic artery occlusion (SAO) shock in urethane anesthetized rats. Occlusion of the superior mesenteric artery for 90 min produced a severe shock state, resulting in a fatal outcome within 120 min of reperfusion in many rats. Defibrotide (10 mg/kg body weight) 10 min prior to reperfusion significantly improved mean arterial blood pressure in comparison to vehicle treated rats (p＜0.05). Defibrotide treatment also significantly attenuated in the increase of plasma amino nitrogen concentration, intestinal myeloperoxidase activity, intestinal lipid peroxidation, infiltration of neutrophils in intestine and thrombin induced adherence of neutrophils to superior mesentric artery segments. Superoxide anion and hydrogen peroxide production in $1{\mu}M$ formylmethionylleucylphenylalanine (fMLP)-activated PMNs was inhibited by defibrotide in a dose-dependent fashion. Defibrotide effectively scavenged hydrogen peroxide, but not hydroxyl radical. Treatment of SAO rats with defibrotide inhibited tumor necrosis factor-${\alpha}$, and interleukin-1${\beta}$ productions in blood in comparison with untreated rats. These results suggest that defibrotide partly provides beneficial effects by preserving endothelial function, attenuating neutrophil accumulation, and antioxidant in the ischemic reperfused splanchnic circulation

• Korean Journal of Remote Sensing
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• v.26 no.3
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• pp.347-359
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• 2010

Ortho-photos provide valuable spatial and spectral information for various Geographic Information System (GIS) and mapping applications. The absence of relief displacement and the uniform scale in ortho-photos enable interested users to measure distances, compute areas, derive geographic locations, and quantify changes. Differential rectification has traditionally been used for ortho-photo generation. However, differential rectification produces serious problems (in the form of ghost images) when dealing with large scale imagery over urban areas. To avoid these artifacts, true ortho-photo generation techniques have been devised to remove ghost images through visibility analysis and occlusion detection. So far, the Z-buffer method has been one of the most popular methods for true ortho-photo generation. However, it is quite sensitive to the relationship between the cell size of the Digital Surface Model (DSM) and the Ground Sampling Distance (GSD) of the imaging sensor. Another critical issue of true ortho-photo generation using high resolution satellite imagery is the scan line search. In other words, the perspective center corresponding to each ground point should be identified since we are dealing with a line camera. This paper introduces alternative methodology for true ortho-photo generation that circumvents the drawbacks of the Z-buffer technique and the existing scan line search methods. The experiments using real data are carried out while comparing the performance of the proposed and the existing methods through qualitative and quantitative evaluations and computational efficiency. The experimental analysis proved that the proposed method provided the best success ratio of the occlusion detection and had reasonable processing time compared to all other true ortho-photo generation methods tested in this paper.

• Journal of Yeungnam Medical Science
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• v.20 no.1
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• pp.1-12
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• 2003

Ischemic stroke is among the principal causes of death and disability in the elderly. Although control of blood pressure, decreased cigarette smoking, and modified dietary habits are among important reasons for stroke decline, the use of antithrombotic therapy, rigorously prescribed. Several antiplatelet agents are approved to reduce the risk of recurrent stroke. Aspirin is the best-studied and most widely used antiplatelet agent for stroke prevention; it provides approximately 15% to 25% relatively risk reduction for secondary prevention of stroke or the major vascular death. Combining 2 antiplatelet agents with different mechanism of action was demonstrated to provide a substantial increase in efficacy in several studies. Anticoagulation should be considered first with potential cardiac sources of embolism. Heparin reduces development of erythrocyte-fibrin thrombi that form in regions of vascular stasis especially within the heart, in severely stenosed arteries sometimes engrafted on white thrombi, in acute arterial occlusion. Heparin should not be indiscriminately given to all acute brain ischemia patients, but may contribute to treatment of large artery occlusion and severe stenosis, cardiogenic embolism with a high acute recurrence risk, and dural sinus and cerebral venous thromobosis.

• Journal of Korean Dental Science
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• v.2 no.2
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• pp.18-23
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• 2009

Introduction : The purposes of this study were to analyze the differences between the anterior and posterior overjets using bracket slot points, and compare two methods of overjet calculation according to different reference points using clinical bracket points on three-dimensional digital models. Methods : A total of 35 normal occlusion models were scanned using a three-dimensional scanner (Orapix$^{(R)}$, Orapix Co., Ltd, Seoul, Korea) and then, virtual brackets (0.022" Slot MBT preadjusted brackets, 3 M Co.CA. USA) were placed on the digital models using virtual setup program (3Txer$^{(R)}$ ver. 1.9.6, Orapix co., Ltd). Archwire-like curves were designed to analyze labial and buccal overjet. Results : There were no statistically significance differences between the right and left overjet and between genders. The average overjet was found to be $1.67{\pm}0.85mm$ at the central incisor area, $2.16{\pm}0.88mm$ at the second premolar and $1.53{\pm}0.71mm$ at the first molar. Conclusion : It is recommended that overjet of individualized upper and lower arch to be 2.0mm at the anterior and posterior teeth.