• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.29 no.6
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• pp.455-459
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• 2003

The Reconstructive techniques of palatal defect are palatal island flap, palatal mucoperiosteal expansion, buccal flap, tongue flap, pushback palatoplasty, free flap and so on. We report a reconstruction of palatal defect using palatal flap. Excellent results were obtained by palatal connective tissue island flap and split thickness pedicle flap. Healing of defect occured rapidly. There were no postoperative complications except dull pain.

• The Journal of the Korean dental association
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• v.16 no.3 s.106
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• pp.235-237
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• 1978

Dr. Walter Wright first presented the results of his studies on acrylic resins in July, 1937. The use of resins for adaptation in inlay and crown and bridge prosthesis was first reported in June 1940 by Harris. There has been now and acceptable list of several physical and mechanical properties of acrylic resins which have been studied to a considerable extent by various researchers, or determined from clinical experience. They include; pleasant esthetics, taste, odor, cleanliness, compatibility with oral tissue, dimensional stability, water sorption by imbibition, hardness, ease and success of repair, weight, thermal coefficient of expansion and strength to resist functional stress. The author carried a series of experiments forward to check the strength. Specimens which were cured at boiling temperature showed weaker strength than those ones which were cured at 72℃.

• International Journal of Stem Cells
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• v.15 no.1
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• pp.60-69
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• 2022

Organoids show great potential in clinical translational research owing to their intriguing properties to represent a near physiological model for native tissues. However, the dependency of organoid generation on the use of poorly defined matrices has hampered their clinical application. Current organoid culture systems mostly reply on biochemical signals provided by medium compositions and cell-cell interactions to control growth. Recent studies have highlighted the importance of the extracellular matrix (ECM) composition, cell-ECM interactions, and mechanical signals for organoid expansion and differentiation. Thus, several hydrogel systems prepared using natural or synthetic-based materials have been designed to recreate the stem cell niche in vitro, providing biochemical, biophysical, and mechanical signals. In this review, we discuss how recapitulating multiple aspects of the tissue-specific environment through designing and applying matrices could contribute to accelerating the translation of organoid technology from the laboratory to therapeutic and pharmaceutical applications.

• Korean Journal of Cleft Lip And Palate
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• v.2 no.1_2
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• pp.29-41
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• 1999

Cleft lip and palate is the most frequent congenital facial deformity of the orofacial area. Successful management of patients with cleft lip / palate requires a multidiciplinary approach from birth to adult stage. Coordinated treatment by the cleft palate team is an essential requirement to obtain optimum treatment results. One of the negative effect of the early surgical interventions of lip and palate is a significant incidence of maxillary growth restriction that produces secondary deformities of the jaws and malocclusion that includes congenital missing of lateral incisor, malformed teeth, rotation or ectopic position of upper anterior teeth, and it has been thought due to the resistance of palatal scar tissue. In Orthodontic treatment for cleft lip / palate patients, expansion of upper dental arch or palatal suture is often needed to correct posterior and/or anterior cross bite and align upper teeth. Various appliances such as hyrax, quad-helix, fan-type expansion screw and jointed-fan type expander can be used for palatal expansion. In the orthodontic treatment of the cleft lip / palate patient, we must consider patient age and severity of palatal constriction for proper appliance selection, and must pay special attention to maintain the treatment results.

• The Korean Journal of Malacology
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• v.29 no.2
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• pp.129-137
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• 2013

This study was conducted to find out the changes of survivorship, respiration and organ structure of Mactra veneriformis exposed to copper (Cu). Experimental period was four weeks. Experimental groups were composed of one control condition and three copper exposure conditions (0.025, 0.050 and 0.100 mg/L). The results of the study confirmed that copper induces reduction of survival rate and respiration rate and histopathology of organ structure of the bivalve. In the copper concentration of 0.100 mg/L, mortality was 100% after Cu exposure of 3 weeks. Respiration rate was observed exposure groups lower than control decline by 75%. Histological analysis of organ system illustrated expansion of hemolymph sinus, disappearance of epidermal layer and degeneration of connective tissue layer of the mantle. Also, histological degenerations as epithelial necrosis and hyperplasia of mucous cells are recognized in the gill and it was observed expansion of hemolymph sinus, disruption of epithelial layer, decrease of mucous cell and degeneration of connective tissue layer in the foot. In the digestive diverticulum, it was showed atrophy of basophilic cell and degeneration of epithelial cell in the digestive tubules, and as the concentration of copper increased the accumulation of lipofuscin increased.

• Polymer(Korea)
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• v.34 no.3
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• pp.253-260
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• 2010

In this study, we prepared and evaluated a series of biocompatible and biodegradable block copolymer hydrogels with a delayed swelling property for tissue expander application. The hydrogels were synthesized via a radical crosslinking reaction of poly(ethylene glycol) (PEG) diacrylate and poly(D,L-lactide-co-glycolide)-poly(ethylene glycol)-poly(D,L-lactide-co-glycolide)(PLGA-PEG-PLGA) triblock copolymer diacrylate as a swelling/degradation controller (SDC). For the synthesis of various SDCs that can lead to different degradation and swelling properties, various PLGA-PEG-PLGA triblock copolymers with different LA/GA ratios and different PLGA block lengths were synthesized and modified to have terminal acrylate groups. The resultant hydrogels were flexible and elastic even in the dry state. The in vitro degradation tests showed that the delayed swelling properties of the hydrogels could be modulated by varying the chemical composition of the biodegradable crosslinker (SDC) and the block ratio of SDC/PEG. The histopathologic observation after implantation of hydrogels in mice was performed and evaluated by macrography and microscopy. Any significant inflammation or necrosis was not observed in the implanted tissues. Due to their biocompatibility, elasticity, sufficient swelling pressure, delayed swelling and controllable degradability, the hydrogels could be useful for tissue expansion and other biomedical applications.

• The korean journal of orthodontics
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• v.31 no.5 s.88
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• pp.499-504
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• 2001

Transverse skeletal deficiency is a common clincal problem associated with narrow basal and dentoalveolar bone. The clinical characteristics of transverse deficiency presents with anterior crowding and posterior buccal crossbite. Orthodontic expansion, using lip bumper and functional devices, was recommanded for younger ages. However, expansion of lower anterior area in older Patients is unstable and tends to relapse toward the original dimension. Distraction osteogenesis is a unique form of clincal tissue engineering and biologic process of new bone formation between bone segments that are gradually separately by incremental traction. Distraction osteogenesis was considered that great potential for correcting transverse mandibular deficiencies. In this Paper, a case of treated transverse deficiency patients with distraction osteogenesis using tooth-borne and tooth & bone-borne distractor is presented.

• Journal of Technologic Dentistry
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• v.23 no.2
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• pp.179-188
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• 2002

With regard to the manufacture of dental prosthesis, all the dental mechanism is of vital significance at the aspect of activating its function by fixing the prosthesis to Patient's oral cavity. However, if there we will take our immediate action without the discretion about its process none the less for the importance of dental mechanism, then we might have a serious problem. Accordingly, there need to pay attention to the dilatability makes up for the shrinkage state occurring by the feature of metal materials and manufacturing process which appeared in the process of dental mechanism, which eventually is expected to playa very important role in casting a dental prosthesis appropriate to one's oral tissue. This study was designed to take into account of the effects on margin consistency of prosthesis according to the continued time of casting-ring in the course of the casting of dental alloy. For this, the researcher made an experiment on the casting of dental alloy, its dilatability, and the change of phase. The results of this study were as follows: First, the researcher could see that the sample which was cast under the condition of $650^{\circ}C/20$ Minutes(the continued time) was far superior to others at the aspect of margin consistency. Second, according to the measurement of expansion coefficient by Dilatometer, the researcher perceived the fact that the expansion-coefficient showed a maximum of $37.1{\mu}m$ considering the sample's length which was cast with ordinary temperature under the condition of $650^{\circ}C/20$ Minutes. Third, from the result of X-ray diffraction under the condition of $650^{\circ}C/20$ Minutes(the continued time), the researcher could find that there's no difference between the change of phase and its intensity. As mentioned above, the researcher could ascertain the fact that its contraction don't give rise to the change of phase.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.2
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• pp.367-373
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• 1992

The author observed a 35-year-old male patient who came to the Dental Infirmary of Kyungpook National University Hospital who had complained of gradual swelling on both side of the mandible for 15 years. As a result of careful analysis of clinical, radiological and histopathological findings, the authors diagnosed it as cementifying fibroma and obtained the results as follows: 1. In clinical examination, main clinical symptom was facial deformity due to gradual swelling on both side of the mandible. 2. In radiographic examination, radiolucent lesions with central radiopaque foci were seen on both mandibular body areas bilaterally, and cortical thinning and expansion of the mandibular body were seen buccolingually. And loss of lamina dura and root resortption of adjacent teeth were also seen. In histopathological examination, this lesion was composed of delicate interlacing collagen fibers interspersed by the fibroblasts and cementoblasts. And round or oval shaped basophilic masses of cementum-like tissue were observed in the connective tissue.

• Imaging Science in Dentistry
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• v.30 no.2
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• pp.123-126
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• 2000

Pyogenic granuloma is a overzealous proliferation of a vascular type connective tissue as a result of some minor trauma and is a well circumscribed elevated, pedunculated or sessile benign inflammatory lesion of skin and mucous membrane. The clinical features of pyogenic granuloma are indicative but not specific and nearly all cases of pyogenic granulomas are superficial in nature, and there is little if any mention in the literature of these lesions producing alveolar bone even jaw bone loss. This case is somewhat unique in that the lesion was an obvious histologic pyogenic granuloma; however, it appeared to invade the mandibular bone which resulted in the loss of the adjacent teeth. A 12-year-old boy came to Seoul National University Dental Hospital with chief complaints of left facial swelling. The features obtained were as follows; Plain radiograms showed a large well-circumscribed radiolucent lesion on left mandibular ramus area, which made severe expansion of lingual cortex and displacement of lower left 3rd molar tooth germ. Computed tomograms showed large soft tissue mass involving left masticator space with destruction of left mandibular ramus. Histologically, sections revealed loose edematous stroma with intense infiltration of inflammatory cells and proliferation of vascular channels. Also, there were focal areas of extensive capillary proliferation, bone destruction and peripheral new bone formation.