• The korean journal of orthodontics
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• v.23 no.4 s.43
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• pp.503-527
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• 1993

This paper describes a new method to create an animal model for TMJ internal derangement in the New Zealand white rabbits and the light and electron microscopical changes of posterior attachment of them. Twenty six rabbits(2.5-3.0kg), four normal and twenty two experimental, were used. The right disc of experimental animal was displaced anteriorly without sectioning the posterior attachment and tied to the zygomatic arch with nylon not to be reduced to the original position. The left TMJ was sham-operated to be compared with its right experimental one. Normal animals were sacrificed one day and eight weeks after experiment. Experimental animals were sacrificed one day, ten days, three weeks, five weeks and eight weeks after surgery respectively. They were fixed intravenously with $2\%$ glutaldehyde under general anesthesia and the samples of them were processed for light and electron microscopic examination. The purpose of this experiment is to make a suitable animal model of disc displacement without reduction for studying and understanding the cellular and morphologic events in posterior attachment of TMJ including early changes which were difficult to be observed in human TMJs. The results of this investigation suggest the following conclusions : 1. Authors induced anterior disc displacement surgically in rabbits with new method to examine histologic changes of posterior attachment. Tissue reactions of this model seem to be similar to those observed in human disc displacement. We think this animal model for anterior disc displacement may be used to explore and evaluate objectively the effects of many treatment modalities in disc displacements. 2. The animal disease model showed inflammation at early stage(one and ten days). At this stage there were mild-to-severe mononuclear inflammatory cell infiltration, numerous newly formed vessels, vessel dilatation and engormement and many fibroblasts. 3. At middle stage(three weeks), fibrosis occurred, where fibroblasts decreased in number, but their cytoplasm was profuse indicating high activity. Collagen fibers increased in number and the tissue looked more dense. 4. At late stage(five weeks and eight weeks) showed degenerative changes including perforation of posterior attachment, disintegration of collagen fiber bundles, degeneration of fibroblasts, metastatic ossification, and dystrophic calcification.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.4
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• pp.359-370
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• 2011

To identify osseointegration of implants, dentists were performed the radiographic analysis. The fractal analysis methods using periapical radiographs before and after loading on implants was to evaluate whether or not significant. 30 patients who were placed implants in dental hospital of Wonkwang university were participated in this study. Total of 42 implants were analyzed. And, 14 males and 16 females aged from 22 to 73 participated in this study. The two morphologic and Fractal analysis of the one trabecular patterns in alveolar bone were done using periapical views. Two periapical views, after implant placement, and after 2 months of functional loading were analysed. The analysis was done by software, Image J(1.40s, National Institute of Health, Bethesda, USA). The data were statistically analyzed using one-way ANOVA(P<.05). Multiple comparison was done by the Tukey HSD test. The results of Fractal analysis and change in bone density around implants showed significantly different values, especially mandibles. However, in case of implants with failure, Fractal values decreased from 1.2865 to 1.1521 and 1.1135 to 1.0478.

• Journal of Korean Neurosurgical Society
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• v.63 no.6
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• pp.698-706
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• 2020

Objective : To study the physiochemical characteristics of podophyllotoxin (PPT) conjugated stearic acid grafted chitosan oligosaccharide micelle (PPT-CSO-SA), and evaluate the ability of the potential antineoplastic effects against glioma cells. Methods : PPT-CSO-SA was prepared by a dialysis method. The quality of PPT-CSO-SA including micellar size, zeta potential, drug encapsulation efficiency and drug release profiles was evaluated. Glioma cells were cultured and treated with PPT and PPT-CSO-SA. The ability of glioma cells to uptake PPT-CSO-SA was observed. The proliferation of glioma cells was determined by 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay. The apoptosis and morphology of U251 cells were observed by 4',6-Diamidino-2-phenylindole dihydrochloride (DAPI) dye staining. Cell cycle analysis was performed by flow cytometry. The migration ability of U251 cells was determined by wound healing test. Results : PPT-CSO-SA had nano-level particle size and sustained release property. The encapsulation efficiency of drug reached a high level. The cellular uptake percentage of PPT in glioma cells was lower than that of PPT-CSO-SA (p<0.05). The inhibitory effect of PPT-CSO-SA on glioma cells proliferation was significantly stronger than that of PPT (p<0.05). The morphologic change of apoptosis cell such as shrinkage, karyorrhexis and karyopyknosis were observed. The percentage of U251 cells in G2/M phase increased significantly in the PPT-CSO-SA group compared with PPT group (p<0.05). Compared with the PPT group, the cell migration ability of the PPT-CSO-SA group was significantly inhibited after 12 and 24 hours (p<0.05). Conclusion : PPT-CSO-SA can effectively enhance the glioma cellular uptake of drugs, inhibit glioma cells proliferation and migration, induce G2/M phase arrest of them, and promote their apoptosis. It may be a promising anti-glioma nano-drug.

• Applied Microscopy
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• v.27 no.2
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• pp.197-215
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• 1997

A morphologic study on the effect of butylated hydroxytoluene (BHT) on experimental hepatocarcinogenesis induced by 3'-methyl-4-dimethyl aminoazobenzene (3'-MeDAB) was investigated. A total of 110 Sprague-Dowley male rats weighting about 200 g each were used for the experiment, and divided into 4 groups; the 3'-MeDAB, BHT, 3'-MeDAB/BHT treated group, and the control group. Four to eight rats of each group were sacrified on the 4th, 8th, 14th and 16th experimental weeks, with continuous pelletized feeding containing 0.09% 3'-MeDAB and 0.5% BHT. The liver was examined by transmission and scanning electron microscopy. The results were as follows; Electron microscopically, the fine structure of the hepatocytes remained consistently abnormal up to 16 weeks after the 3'-MeDAB treatment. There was no significant difference in the groups observed earlier than in the ones observed later. Many subcellular changes were observed : nuclear change, decreased glycogen, mitochondrial abnormalities, disaggregated rough endoplasmic reticulum, marked proliferation of smooth endoplasmic reticulum, dilatation and distortion of bile canaliculi, increased lysosomes, apoptotic bodies, migration of bile ductule cell. In the BHT treated group, the ultrastructural changes of hepatocytes were not significant, except for the lipid droplets and proliferated smooth endoplasmic reticulum among hepatocytes depending on the experimental duration. The various subcellular changes of 3'-MeDAB/BHT treated groups were simillar to those of the 3'-MeDAB treated group, but the degree of changes in the 3'-MeDAB/ BHT treated group decreased compared with those of the 3'-MeDAB treated group. These results suggest that dietary butylated hydroxytoluene has a protective/inhibitory effect on the hepatocarcinogenesis induced by 3'-methyl-4-dimethyl -aminoazobenzene.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.228-243
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• 1997

The changes of microstructures, morphology of sclerotic dentin and bonding aspects generated by an adhesive resin was investigated. Incisors and premolars showing natural cervical abrasions were collected and conditioned with 10 % phosphoric acid or 10 % maleic acid. The sclerotic dentin specimens were then rinsed and blot-dried and applied with dentin adhesive (All Bond 2) to the conditioned dentin surface. To examine the morphologic change of the sclerotic dentin specimen after etching and bonding procedure, the treated specimens were examined by SEM. To analyze the chemical composition of sclerotic dentin and crystals occluding dentinal tubules, the sclerotic dentin specimen was powdered and examined with X-ray Diffractometer. To investigate the Ca/P weight percent ratio within the dentinal tubules, the sclerotic dentin specimen was fractured perpendicularly to the long axis of the tooth from the center of cervical abrasion lesion and then examined with EDX(Energy Dispersive X-ray) microanalyzer. The results were as follows : 1. The increased width of peritubular dentin and the depositions of the irregular amorphous materials within the dentinal tubules were showed in the sclerotic dentin specimens. 2. After the treatment of sclerotic dentin specimen with 10 % phosphoric acid or 10 % maleic acid, the lateral side of tubules rather than cross-sectional tubule openings was showed exclusively at the incisal and gingival incline of the specimens. 3. After the treatment of sclerotic dentin specimen with 10 % phosphoric acid or 10 % maleic acid, the hybrid layer was not formed evidently and the resin tag was not formed or shortly penetrated into the tubules with the thinner diameter. 4. According to the results of XRD analysis of the sclerotic dentin specimen, Hydroxyapatite and Octacalcium phosphate were predominent, however, Whitlockite crystals were rare. 5. The mean Ca/P weight percent ratio analysed from 5 fractured sclerotic dentin specimens was $2.322{\pm}0.170$ at the intertubular dentin, $1.826{\pm}0.051$ within the dentinal tubule.

• Microbiology and Biotechnology Letters
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• v.33 no.3
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• pp.169-177
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• 2005

This study focuses on investigating roles of microorganisms in decontamination of reed rhizosphere in Sunchon Bay, Korea, which is considered one of the marsh and mud environment severely affected by human activities such as agriculture and fisheries. In general, the bay is known to play the role of the buffering zone to reduce the sudden impact or change by environmental stresses. In our initial efforts to elucidate the microbial functions in decontamination process in reed rhizosphere, pure bacteria capable of degrading aromatic hydrocarbons were isolated from reed (Phragmites communis) rhizosphere of Sunchon bay by enrichment culture using either benzene, toluene, ethylbenzene, or xylene (BTEX) as a sole source of carbon and energy. Measurement of the rates of BTEX degradation and cell growth during the incubation in BTEX media under several temperature conditions demonstrated maximized degradation of BTEX at $37^{\circ}C$ in both strains. Both strains were also resistant to all the heavy metals and antibiotics tested in this study, as well as they grew well at $42^{\circ}C$. Identification of the isolates based on 16S rRNA gene sequences, and a variety of phenotypic and morphologic properties revealed that the two strains capable of BTEX catabolism were among Microbacterium sp., and Rhodococcus sp. with over $95{\%}$ confidence, designated Microbacterium sp. EMB-1 and Rhodococcus sp. EMB-2, respectively This result suggested that in the rhizosphere of reed, one of major salt marsh plants they might play an important roles in decontamination process of reed rhizosphere contaminated with petroleum such as BTEX.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.620-627
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• 2005

The purposes of early orthodontic intervention are to correct obvious problems, to intercept developing problems and prevent them from becoming worse. Myofunctional influence on facial growth and the dentition change in muscle function and initiate morphologic variation in the normal configuration of the teeth and enhance an already existing malocclusion. Myofunctional therapy has been advocated since 1960's as the treatment for tongue thrust and other oral habits. Pre-orthodontic $TRAINER^{(R)}$ is introduced as functional device usable in children of mixed dentition to correct functional problems concerning soft tissue, tooth and skeleton. The most common cases to treat with Pre-orthodontic $TRAINER^{(R)}$ are lower anterior crowding, anterior open bite, Class II malocclusion and deep bite. Also, it can be used as correction of oral habits. Patients in this cases visited Department of Pediatric Dentistry, School of dentistry, Dankook University for orthodontic treatment. Pre-orthodontic treatment with Pre-orthodontic $TRAINER^{(R)}$ was carried out for correction of the oral habits.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.713-719
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• 1995

These studies were carried out to investigate the effects of Puerariae radix catechins(PRC) administration on the biochemical parameters of liver function in liver of carbon tetrachloride(CCl4)-treated rats. Thirty six healthy Sprague-Dawley rats weighing about 120g were used for this experiment and divided intot he following 3 groups : normal control group(NCON), $CCl_4$ control group(CCON), PRC treated group(PRC). Fifty percent $CCl_4$ in oil was administered(I.P.) by 2ml per kg body weight two times a week for 3 weeks. PRC treated groups were administered orally at the leaves of 1% per day in distilled water for 8 weeks. Lipid hydroperoxides were analyzed by using chemiluminescence-high performance liquid chromatography(CL-HPLC) method as a phosphatidylcholine hydroperoxide value(PCOOH) in liver tissues. $CCl_4$ treatment significantly(p<0.05) resulted in an increase in GPT & GOT activities and liver hydroperoxide values comparing with those of the untreated control, while administration of PRC to the $CCl_4-treated$ rats significantly(p<0.001) decreased GPT & GOT activities and liver hydroperoxide value. Their ultrastructual changes of hepatocellular organelles were shown to clarify the morphologic nature of protective effects of PRC on hepatocytic injuries. $CCl_4$ treatment observed to change the ultrastructual nature of outer membrane of hepatocytes. However, the hepatic changes on PRC treatment to $CCl_4$ group was not found. PRC administration may inhibit the formatiion of liver lipid hydroperoxides in vivo and were very effective in recovering the liver function in $CCl_4-treated$ rats.

• The Journal of Korean Academy of Prosthodontics
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• v.44 no.1
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• pp.112-123
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• 2006

Purpose: The biocompatibility and bio-adhesive property of a dental implant abutment are important for proper soft tissue healing and maintenance of osseointegration of implant. However, studies of soft tissue healing and mucosal attachment of various materials of implant abutment other than titanium are still needed. In this study, cell attachment, proliferation, cytotoxicity of human gingival fibroblast for ceramic, gold alloy, Ni-Cr alloy and, commercially available pure titanium as a control were evaluated, using MTS and scanning electron microscopy. Materials and Methods: Specimen was designed to disc, 4mm diameter and 1mm thickness, made of ceramic, gold alloy, Ni-Cr alloy and commercially available pure titanium. Primary culture of human gingival fibroblasts were grown in Dulbecco's modified Eagle's medium with 10% fetal bovine serum and 1% antibiotics. Cells were inoculated in the multiwell plates placed the specimen disc. Cell Titer 96 AQucous One Solution Cell Proliferation Assay were done after 1hour 3hours, 24hours, 3days, 5days of incubation. The discs were processed for scanning electron micrography to evaluate cell attachment and morphologic change. Results: The results were obtained as fellows. 1. The ceramic showed high cell attachment and proliferation and low cytotoxicity, which is as much bioadhesive and biocompatible as titanium. 2. The gold alloy represented limited proliferation of human gingival fibroblast and the highest cytotoxicity among tested materials (p<0.05). 3. The Ni-Cr alloy limited the proliferaion of the human gingival fibroblast compared to titanium(p<0.05) but cytotoxicity on the bottom of well was not so considerable, compared to titanium. 4. On the scanning electron micrographs , the ceramic showed good attachment and proliferation of human gingival fibroblast, which was similar to titanium. But gold alloy and Ni-Cr alloy showed the shrinkage of gingival fibroblast both after 24 hours and 3 days. On 5th day, small amount of the human gingival fibroblast proliferation was observed on the Ni-Cr alloy, while the shrinkage of gingival fibroblast was still observed on the gold alloy. Conclusions: These results suggest that the ceramic abutment is as biocompatible as titanium to make proper mucosal seal. The gold alloy has a high cytotoxicity to limit proliferation of gingival fibroblast, which suggest limited use on the anterior tooth where soft tissue healing is recommeded.

• The Journal of Korean Academy of Prosthodontics
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• v.34 no.3
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• pp.593-610
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• 1996

The objective of this paper was to evaluate the shear bond strength of luting glass ionomer cement with defferent calcium based solution treatment on dentin surface. 120 extracted human teeth were classified into 12 group based on presence of smear layer on dentin surface and type of treatment solution. Smear layer remove on dentin surface was done using 6% citric acid for 60 seconds. Five different dentin surface treatment solutions(calcium acetate, calcium carbonate, clacium chlorided, calcium hydroxide, and calcium phosphate) were evaluated in this study. After surface modification, metal ring(inner diameter : 3mm, depth : 1mm) was placed to expose the same dentin surface area and inner space was filled with luting glass ionomer cement according to the recommended procedure for stadard clinical procedure. The shear bond strength of glass ionomer cement was determined after 24 hours. SEM was used for the evaluation of the surface morphologic changes and EDAX analysis was done for determination of the change of the calcium contents of treated dentin. Follwing conclusion can be drawn : 1. In the group of the dentin surface with smear layer, the calcium carbonate solution was the most effective for the increase of the clacium content and the shear bond strength of glass ionomer cement to dentin surfaces. 2. In the group of the calcium carbonate treated dentin with msear layer, the shear bond strength was increased twice compared to the control group and cohesive failure mode was observed. 3. The shear bond strength of cement was increased significantly be the removal of smear layer using 6% citric aicd. However, additional calcium solution treatments were not effective for further bond strength increase. 4. The shear bond strength of cement was significantly improved by both of the removal of smear layer and the calcium solution treatment, and the former was more effective for bond strength improvement. 5. The smear layer removed/calcium solution treated groups showed dentinal tubule obstruction and crystal attachment in SEM evaluation. However, the shear bond strengths of these groups were not increased compared to the smear layer removed/no dentin treatment group.