• Journal of the Institute of Electronics Engineers of Korea CI
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• v.48 no.5
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• pp.49-54
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• 2011

Case-based reasoning is an efficient method to find solutions for new problems by using past cases after appropriate changes. It is widely used in everyday life because it resembles the way human acts. In this paper, we propose a military system that generates the most appropriate tactics for CGF (Computer Generated Forces) by utilizing past practices. It indeed applies case-based reasoning at the process of armed conflict. When the CGF squad on a mission, they will be given an action plan to reach the final goal. In the process of executing, tactics for specific action should be organized such as attacks, ambushes, and tactical moves. By using the proposed method, tactics were generated by case-based reasoning. The proposed system successfully receives input through each command and control agent, measures the degree of similarity with the case in case DB, selects the most similar case, modifies, uses, and then stores it for next time.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.127-133
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• 1998

An impacted tooth is defined pathologically as a tooth that remains under the mucosa of inside bone without eruption of the crown after a specific period of eruption. Clinically, the term includes those teeth, even before eruption period, that are not expected to erupt due to shape, position and alignment of tooth and lack of space. Canine is prone to impaction more than other teeth because it has the longest time to develop and a complex route from the place of formation to the site of eruption. The impaction incidence of maxillary canine is repoted 0.92$\sim$3.3% (Ferguson, 1990). In 1995 Orton reported that the incidence was 0.92$\sim$2.2% and palatal impaction was more frequent than labial impaction(85%:15%). In 1969 Johnston presented it was more common to woman than to man(3:1). The etiology includes systemic disease such as endocrine disorder, cleidocranial dysostosis, irradiation, Crouzon syndrome, ricketts, facial hemihypertrophy and hereditary and local problems such as ectopic position of the tooth, distance of tooth from its place of eruption, malformation of the tooth, presence of supernumerary teeth, trauma of tooth germ, infection of tooth germ, displacement of tooth germ or tooth by a neoplasm, ankylosis, overretention of deciduous predecessor, lack of space for the tooth in the dental arch and mucosal barrier due to gingival fibrosis. The maxillary canine is especially important as it has the longest root, provides guidance for lateral movement of the mandible and masticatory function and assumes an important role esthetically as it is located at mouth angle. If left untreated, it may cause migration and external, internal resorption of adjacent teeth, loss of arch length, formation of dentigerous cyst or tumors, infection and referred pain as well as malposition of the tooth. Therefore, periodic examination of the development and eruption of the maxillary canine is especially important in a growing child. This case study presents the results of treatment of palatally impacted maxillary canine utilizing surgical exposure and orthodontic tooth movement on patients visiting SNUDH dept. of pediatric dentistry.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.665-670
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• 2004

The mandibular buccal frenum becomes a problem when its attachment is too close to the marginal gingival. Heavy buccal frenum mucogingivally results in insufficient attached gingiva, inadequate vestibular depth and also difficulty in eruption of mandibular premolar. The aim of this study is to demonstrate the effectiveness of apically positioned partial-thickness flap as adequate method in order to remove heavy buccal frenum and expose impacted teeth. The author presents the case of a 12-year-old boy. He had problems that was prolonged eruption of #34, #35 due to high pull buccal frenum. After space regaining for normal eruption of #34, #35, we performed apically positioned partial-thickness flap on #34, 35 area. As a results, we confirmed that eruption of #34, #35 has been processed normally And vestibular depth, position of buccal frenum and width of attached gingival was within a normal range. Decrease in muscle pull, adequate width of attached gingiva and increased vestibular depth can be expected from this treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.645-650
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• 2004

Calcifying odontogenic cyst(COC) is a rare developmental odontogenic cyst, which shows diverse classification and terminology. Cystic epithelial lining of COC is composed of basal cell layer of columnar cells and overlying layer of stellate reticulum. In the epithelium, ghost cells that might induce adjacent mesenchymal tissue to develop dental organ are shown characteristically. In spite of low rate of recurrence, we have to get a histopathological examination so that odontogenic lesions may recur without fully curettage of lining epithelium. 7-year-old male child came pediatric dentistry in wonkwang university dental hospital in order to check the delayed eruption of left maxillary central incisor. Radiographic examination revealed a well-defined radiopaque mass, overlapping impacted left central and lateral incisor crown. Enucleated mass was tooth-like features and also had epithelium lining. Results of histopathologic procedure, we saw the lots of ghost cell and proliferating hard dental tissues. Also we saw the cystic epithelium cells. It revealed diagnosis of the COC associated complex odontoma. For this reason one should consider of COC when patients present odontoma-like lesion with impacted tooth.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.3
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• pp.291-301
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• 2021

The aim of this study is to compare the properties of odontoblast gene of early passage cells and late passage cells derived from impacted maxillary supernumerary teeth. Impacted supernumerary teeth with maxilla were extracted from 12 patients (8 males, 4 females) between 6 - 9 years old without medical history. Real-time polymerase chain reaction (PCR) was conducted to compare characterization of odontoblast cell in the 3rd and 10th passage, and between with bone inducing additive group and without additive group. Genes for odontoblasts characteristics are osteonectin (ONT), alkaline phosphatase (ALP), osteocalcin (OCN), dentin matrix protein 1 (DMP-1) and dentin sialophosphoprotein (DSPP). The level of gene expression was in a decreasing order of ONT, ALP, OCN, DMP-1 and DSPP in the 3rd passage, and in decreasing order of ONT, DMP-1, OCN, ALP, and DSPP in the 10th passage in the undifferentiation and differentiation group. The order of ONT, DMP-1, and OCN did not changed. ALP and DMP-1 were switched in order. ALP and DMP-1 may be used as important markers for differentiating between the 3rd passage and 10th passage cells. Considering that supernumerary tooth was extracted young age and the time required to cultured 10th passage was short, supernumerary tooth can be considered a useful donor site of dental pulp stem cells.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.6
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• pp.275-284
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• 2023

Virtual reality simulations are used for education and training in various fields, and are especially widely used in the medical field recently. The education/training simulator consists of tactile/force feedback generation and image/sound output hardware that provides a sense similar to a doctor's treatment of a real patient using real surgical tools, and software that produces realistic images and tactile feedback. Existing simulators are complicated and expensive because they have to use various types of hardware to simulate various surgical instruments used during surgery. In this paper, we propose a dental surgical simulation system using a force feedback device and a morphable haptic controller. Haptic hardware determines whether the surgical tool collides with the surgical site and provides a sense of resistance and vibration. In particular, haptic controllers that can be deformed, such as length changes and bending, can express various senses felt depending on the shape of various surgical tools. When the user manipulates the haptic feedback device, events such as movement of the haptic feedback device or button clicks are delivered to the simulation system, resulting in interaction between dental surgical tools and oral internal models, and thus haptic feedback is delivered to the haptic feedback device. Using these basic techniques, we provide a realistic training experience of impacted wisdom tooth extraction surgery, a representative dental surgery technique, in a virtual environment represented by sophisticated three-dimensional models.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.3
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• pp.499-506
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• 1999

The odontoma is relatively a common benign odontogenic tumor and caused by overgrowth of odontogenic tissues. The recent classification by World Health Organization divides odontoma into 2 groups such as compound odontoma and complex odontoma. Compound odontoma comprises dental tissues, resembling the morphology of a tooth and has predilection for the anterior maxilla. In contrast, complex odontoma has unorganized mass, not resembling the normal tooth and has predilection for the posterior mandible. The etiology of odontoma is unknown and almost asymptomatic. So, it usually is found in routine radiographic examination, and most common presenting symptom is impacted or unerupted permanent teeth and retained primary teeth. It can occurs almost anywhere in jaws. It is desirable that odontoma should be removed by surgical enucleation including follicle and surrounding soft tissues. Considering the age and behavioral cooperation of patient, the development of permanent dentition, the location of odontoma in jaw, the need for the concomitant operative dentistry, operation is performed in outpatient department with/without sedation or under general anesthesia with endotracheal intubation. In this case report, 2 patients with compound odontoma were treated by surgical enucleation including follicle and surrounding soft tissues. One patient, about 5 years old, was treated under general anesthesia and concomitant operative dentistry was performed. The other patient, about 11 years old, was treated under local anesthesia in outpatient department. In 2 cases, after 4 months, surgical defects were filled with new bone and normalization of eruption path of impacted permanent teeth was observed.

• Journal of agricultural medicine and community health
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• v.25 no.2
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• pp.427-440
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• 2000

A comparative study was made about health resources, medical care service statistics and public health service statistics by health subcenters at Jangdong and Jangpyung townships, Jangheung County, Chollanamdo before and after the unification of two health subcenter to improve their function. 1. While two general physicians, one dentist, 4 nurse aids arid one oral hygienist were working at two health subcenters with simple facility with examination room and public health office in 1997 prior to the unification, in 1999 after the unification of two health subcenters 14 staff including a specialist physician, a general physician, a dentist, a herb hygienist, a radiology technician and a physical therapist were working in the new health subcenters equipped with appropriate facilities in two storey building. 2. In 1997 before the unification the yearly total income of two health subcenters was 78,815 thousand won(about 14,000 won per capita) and the amount was 140,376 thousand won(about 25,000 won per capita) in 1999 after the unification. And the income was used for operation of health subcenters excluding personnel expense. 3. While 90.5% of visitors to the health subcenters came for general medical care, and 91.6% came for the revisit before the unification, after the unification 71.2% came for general medical care, 10.8% for dental care, 16.5% for oriental physician's care, 29.7% for the first visit and 70.3% for revisit. Most common problem cared for was musculoskeletal disorder like arthralgia. Average treatment cost per person per month was 9,363 won before the unification and 8,309 won after the unification. 4. Through the comparison of execution rate of public health services before and after the unification. the practice rate of most health service among target population including visiting service for chronic illness, maternal and child health service and immunization service increased after the unification. The practice rate of tuberculosis control service, hypertension control and diabetes management was a little decreased. In conclusion, continuous effort to satisfy all persons in two townships and evaluation are necessary to coincide with the spirit of unification of two health subcenters.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.3
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• pp.186-196
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• 2010

Introduction: The first aim of this study was to isolate the dental tissue-derived stem cells from the dental follicle (DF), dental pulp (DP), and root apical papilla (RAP) of the extracted wisdom teeth. Second was to evaluate their characterization with the expressions of transcription factors and cell surface markers. Finally, their ability of the in vitro multi-lineage differentiations into osteogenic and adipogenic cells were compared, respectively. Materials and Methods: Dental tissues, including dental follicle, dental pulp, and root apical papilla, were separated in the extracted wisdom teeth. These three dental tissues were cultured in Dulbecco’s modified Eagle’s medium (DMEM) with supplements, respectively. After passage 3, the homogeneous shaped dental tissue-derived cells were analyzed the expression of transcription factors (Oct-4, Nanog and Sox-2) and cell surface markers (CD44, CD90 and CD105) with reverse transcription polymerase chain reaction (RT-PCR) and fluorescence-activated cell sorting (FACS) analysis. In order to evaluate in vitro multi-lineage differentiations, the culture media were changed to the osteogenic and adipogenic induction mediums when the dental tissue-derived cells reached to passage 3. The characteristics of these three dental tissue-derived cells were compared with immunohistochemistry. Results: During primary culture, heterogenous and colony formatted dental tissue-derived cells were observed in the culture plates. After passage 2 or 3, homogenous spindle-like cells were observed in all culture plates. Transcription factors and mesenchymal stem cell markers were positively observed in all three types of dental tissue-derived cells. However, the quantity of expressed transcription factors was most large in RAP-derived cells. In all three types of dental tissue-derived cells, osteogenic and adipogenic differentiations were observed after treatment of specific induction media. In vitro adipogenic differentiation was similar among these three types of cells. In vitro osteogenic differentiation was most strongly and frequently observed in the RAP-derived cells, whereas rarely osteogenic differentiation was observed in the DP-derived cells. Conclusion: These findings suggest that three types of human dental tissue-derived cells from extracted wisdom teeth were multipotent mesenchymal stem cells, have the properties of multi-lineage differentiations. Especially, stem cells from root apical papilla (SCAP) have much advantage in osteogenic differentiation, whereas dental follicle cells (DFCs) have a characteristic of easy adipogenic differentiation.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.1
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• pp.77-94
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• 2021

The purpose of this study was to investigate the three-dimensional characteristics of mesiodens using Cone-beam Computed Tomography(CBCT) and analyze the factors affecting complications and anesthetic methods of extraction. This study evaluated 602 mesiodens of 452 patients who underwent extraction of mesiodens at the department of Pediatric Dentistry in Seoul National University Dental Hospital between 2017 and 2019. The ratio of mesiodens patients over total patient per year was gradually increased over the past 20 years. Mesiodens with labio-palatally horizontal direction while root directing labial were the most common among the mesiodens with horizontal direction. Mesiodens were the most common at the cervical side of the adjacent teeth(37.0%) and mesiodens located in the near-palatal side were observed about 3.83 times higher than the far-palatal side. Most of the mesiodens(82.1%) were in contact with adjacent permanent teeth on all three sides of the CBCT and 46.2% of mesiodens had curved roots. The patient's age, vertical position, presence of complications, and proximity showed a significant difference in the selection of general anesthesia among anesthetic methods. The direction and vertical position of mesiodens had a significant effect on complications. These results provide a better understanding of mesiodens for establishing an accurate diagnosis and treatment plan.