• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.324-331
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• 2001

The present study was aimed to investigate the effects of latency period on alveolar ridge distraction using the intraoral distraction device. Nine adult mongrel dogs of either sex, weighing about 15kg, were used. They were divided into 3-day, 5-day, and 7-day groups according to the latency period. The left upper and lower premolars and first molars were extracted. Twelve weeks after the extraction, an osteotomy was performed and the distraction device was applied. After the latency period, the distraction was applied at a rate of 1.2mm for 8 days. The distraction device was left in place for 2 weeks to allow consolidation and was then removed. The animals were sacrified at 8 weeks after completion of distraction and were examined macroscopically, radiographically, and histologically. After completion of the distraction, the alveolar crest protruded prominently, showing the vertical augmentation of the alveolar bone. Soft tissues were broken down after the 6th day of distraction in 3-day latency group, and premature union occurred on the 7th day of distraction in the 7-day latency group. The average distance was $9.40{\pm}0.3mm$ in 3-day latency group, $9.35{\pm}0.1mm$ in 5-day latency group, and $8.85{\pm}0.1mm$ in 7-day latency group. In the radiograph taken at 8 weeks after distraction, there was slight bone resorption around the medial and distal edges of the alveolar bone segment, and a new bone deposition was observed in the neighboring alveolar crest area in all groups. Fibrous tissues were present in a part of the buccal cortical bone area of the distraction gap, and the woven and lamellar bones were observed in the distracted gap. There were bony bridges in the distraction gap in all animals examined. These results suggest that optimal time of latency period on alveolar ridge distraction using the intraoral distraction device is about 5 days in dogs, and about 7days in human beings.

• The korean journal of orthodontics
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• v.14 no.2
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• pp.187-202
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• 1984

There are evidences that exogenous electric currents are capable of enhancing bone formation and resolution, and that the conversion of the bioelectric response to biochemical activity provides the directional component of orthodontic tooth movement. In addition, evidence has implicated cyclic nucleotides in alveolar bone cellular activation mechanism during orthodontic tooth movement. In view of these evidences, this study was performed to investigate the effects of exogenous electric currents on cyclic nuclotide levels in feline alveolar bone and the possible clinical application of electric currents as an additional orthodontic tool. In the first study, three groups of three adult cats were subjected to application of a constant direct current of $10{\pm}2$ microamperes to gingival tissue near maxillary canine noninvasively for 1, 3, and 7 days respectively. In the second study, three groups of three adult cats each were treated by an electric-orthodontic procedure for 1, 3, and 7 days respectively. The left maxillary (control) canine received an orthodontic force of 80gm alone at time of initiation, while the right maxillary (experimental) canine received combined force-electric stimulation (80gm of force and $10{\pm}2$ microamperes of a constant D.C. currents). Alveola, bone samples were obtain from the mesial (tension and/or cathode) and the distal (compression and/or anode) sites surrounding maxillary canines as well as from contralateral control sites. The samples were extracted, boiled, homogenized, and the supernatants were assayed for cyclic nucleotides (cAMP, cGMP) by a radioimmunoassay method. And also the amount of tooth movement was measured in the second study. On the basis of this study, the following conclusions can be drawn: 1. The fluctuation pattern of cyclic nucleotide levels in alveolar bone treated by exogenous electric currents was similar to that treated by orthodontic force. 2. The cAMP levels in alveolar bone of electrically treated teeth significantly elevated above the control values. And of electrically treated teeth, the values of the anode sites were higher than those of the cathode sites. 9. The cGMP levels in alveolar bone of electrically treated teeth elevated above the control values at the initiation phase of treatment, but dropped below the control values at time of termination. And of electrically treated teeth, the values of the cathode sites were higher than those of the anode sites. 4. The rate of tooth movement in teeth . treated by force-electric combination increased with the length of treatment as compared to that treated by mechanical force alone.

• International Journal of Oral Biology
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• v.42 no.3
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• pp.137-142
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• 2017

To determine the effect of the tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) in odontoclast formation, we administrated a $TNF-{\alpha}$ inhibitor in rats with diabetes rats with periodontitis. The rats included in the study were divided into three groups: control rats without diabetes or periodontitis (the C group), rats with periodontitis and diabetes (the PD group), and rats with periodontitis and diabetes treated by infliximab, the TNF inhibitor (the PD+infliximab group). The PD and PD+infliximab groups received intravenous administrations of streptozotocin (STZ, 50 mg/kg) to induce diabetes. After 7 days of STZ injections, the mandibular first molars were ligatured to induce periodontitis. The PD+infliximab group was intrapenitoneally administrated by infliximab (5 mg/kg). On days 3 and 20 after the ligature administration, odontoclast formation along root surfaces was evaluated by tartrate resistant acid phosphatase (TRAP) staining and cathepsin K immunohistochemistry. On day 3, the number of TRAP- and cathepsin K-positive cells increased more so in the PD group than in the C group. The PD+infliximab group showed a lower number of positive cells than the PD group. There was no difference in all the groups on day 20. On day 3, the cathepsin-K positive multinucleated and mononucleated cells were higher in the PD group than in the C group. The number of cathepsin-K positive multinucleated cells was lower in the PD+infliximab group than in the PD group. The PD group showed more cathepsin K-positive cells in the furcation and distal surfaces than the c group. The Cathepsin K-positive cells of the PD+infliximab group were lower than that of the PD group in furcation. These results suggest that $TNF-{\alpha}$ stimulates odontoclast formation in diabetes with periodontitis.

• Journal of Oral Medicine and Pain
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• v.25 no.4
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• pp.415-425
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• 2000

In order to obtain the basic data concerning the optimal lasing conditions in using Nd:YAG laser as an adjunctive modality of periodontal therapy of root planing without irreversible structural deterioration of cervical cementum, the author selected 36 human teeth having no cervical abrasion and caries (; 12 anteriors, 12 premolars. 12 molars) extracted due to periodontal diseases, and divided them into 4 groups as Group I, II, III and IV (; each group of 3 anteriors, 3 premolars, 3 molars), and prepared a cementum specimen with thickness of $1.0mm{\pm}0.2mm$ sectioned longitudinally at the middle of mesio-distal thickness (; Group I) or horizontally at 1mm-2mm below the cemento-enamel junction (; Group II, III, IV) from each tooth of each group by low speed diamond wheel saw, and treated them with 0.5 M ethylene diamine tetraacetic acid (; EDTA, pH=7.4) for 2 minutes for elimination of remnants during tooth-sectioning. And the author applied the laser energy from a fiberoptic delivered, free running, pulsed Nd:YAG laser (; wavelength 1064nm. pulse duration $120{\mu}sec$, fiber diameter $320{{\mu}m}$) to cementum surfaces in triplicates of one experiment under the following lasing conditions: 1. stationary mode of fiber in contact to cementum surfaces without air-spray (; Group I )/with air-spray (; Group II), 2. unidirectional moving mode of fiber in contact to cementum surfaces under speed of 3mm-4mm/sec without air-spray (; Group III)/with air-spray (; Group IV), 3. energy per pulse (mJ/pulse) [; energy density ($J/cm^{2}$)] in order of 1.0W/10Hz (100J/pulse); $124J/cm^{2}$, 0.5W/10Hz (50mJ/pulse); $62J/cm^{2}$, 0.4W/10Hz (40mJ/pulse); $50J/cm^{2}$, 0.3W/10Hz (30mJ/pulse); $37J/cm^{2}$, 4. exposure time of 1 second. And the author applied the platinum coating on surfaces of cementum specimens, and evaluated the characteristics of ultrastructural change on surfaces of cementum using the scanning electron microscopy. In general the ultrastructural loss of cervical cementum irradiated under the same lasing condition of laser energy density occurred least in specimens of Group IV. And especially, the ultrastructural loss of cervical cementum irradiated under the laser energy density of $37J/cm^{2}$ almost did not occur in specimens of Group IV. Therefore, it is considered that the pulsed Nd:YAG laser should be applied with the lasing conditions of unidirectional moving mode of fiber in contact to cementum surfaces under speed of 3mm-4mm/sec with air-spray and of laser energy density within $37J/cm^{2}$ as an adjunctive modality of periodontal therapy of root planing without irreversible structural deterioration of cervical cementum.

• Journal of Korean Foot and Ankle Society
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• v.21 no.4
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• pp.135-138
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• 2017

Purpose: The purpose of this study is to determine the correlation between the correction loss of hallux valgus angle and the severity of valgus angle of the second toe. Materials and Methods: We selected 312 cases from 268 surgical patients with hallux valgus deformity receiving distal chevron osteotomy. For a radiological evaluation, we analyzed the changes in the hallux valgus angles, first to second intermetatarsal angles, and valgus angle of the second toe post index operations. All patients were women; the mean age was 46 years. The mean follow-up period was 17 months. Results: The mean hallux valgus angle was $33.6^{\circ}$ preoperatively (range, $25.7^{\circ}{\sim}44.8^{\circ}$), $13.1^{\circ}$ (range, $8.4^{\circ}{\sim}16.4^{\circ}$) after 4 weeks of postoperative period, and $17.1^{\circ}$ (range, $9.4^{\circ}{\sim}28.5^{\circ}$) at their final follow-up. The mean valgus angle of the second toe was $8.4^{\circ}$ preoperatively (range, $2.0^{\circ}{\sim}25.8^{\circ}$) and $8.3^{\circ}$ (range, $1.7^{\circ}{\sim}24.9^{\circ}$) at the final follow-up. Preoperatively, there was a positive correlation between the valgus angle of the second toe and hallux valgus angle (r=0.747, p=0.001). The correction loss of hallux valgus angle had a significant correlation with the severity of valgus angle of the second toe (r=0.802, p=0.001). Conclusion: The existence of the second toe valgus deformity may present itself as a cause of correction loss of hallux valgus angle. The preoperative measurement of the second toe valgus angle may be a good predictor of correction loss; therefore, thorough preoperative warning on the possibility of correction loss should be conducted to maximize patient satisfaction after the procedure.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.4
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• pp.425-442
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• 2004

Statement of problem: A difficulty in achieving a passive-fitting prosthesis can be overcome by individual crown restoation of multiple implants. But individualized crown has another difficulty in control of contact tightness and stress distribution. Purpose: This in vitro study is to evaluate the stress distribution and the magnitude in the supporting tissues around Endopore implants with different crown lengths, interproximal contact tightness, and the splinting effects. Material & methods: Three Endopore implants($4.1{\times}9mm$) were placed in the mandibular posterior edentulous area distal to the canine and photoelastic model was made with PL-2 resin(Measurements Group, Raleigh, USA). Restorations were fabricated in two crown lengths: 9, 13 mm. For non-splinted restorations, individual crowns were fabricated on three custom-milled titanium abutments. After the units were cemented, 4 levels of interproximal contact tightness were evaluated: open, ideal($8{\mu}m$ shim stock drags without tearing), medium($40{\mu}m$), and heavy($80{\mu}m$). For splinted restorations, 3-unit fixed partial dentures were fabricated. This study was examined under simulated non-loaded and loaded conditions(6.8 kg). Photoelastic stress analysis was carried out to measure the fringe order around the implant supporting structure. Results: 1. When restorations were not splinted, the more interproximal contact tightness was increased among the three implants, the more stress was shown in the cervical region of each implant. When crown length was increased, stresses tended to increase in the apex of implants but there were little differences in stress fringes. 2. When nonsplinted restorations were loaded on the first or third implant, stresses were increased in the apex and cervical region of loaded implant. Regardless of interproximal contact tightness level, stresses were not distributed among the three implants. But with tighter interproximal contact, stresses were increased in the cervical region of loaded first or third implant. 3. When the nonsplinted restorations were not loaded, there were little stresses on the supporting structure of implants, but low level stresses were shown in the splinted restorations even after sectioning and soldering. 4. With splinted restorations, there were little differences in stresses between different crown lengths. When splinted restorations were loaded, stresses were increased slightly on the loaded implant, but relatively even stress distribution occurred among the three implants. Conclusions: Splinting the crowns of adjacent implants is recommended for Endopore implants under the overloading situation.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.800-806
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• 2013

The purpose of this study was to evaluate the marginal fitnesses on the effect of span length of bridge and the marginal gaps within the clinically allowed range. The samples were fabricated with zirconia core using CAD/CAM system. The test groups were divided by four groups, single crown, 2-units bridge, 3-units bridge and 4-units bridge and 10 zirconia cores per each group. The results of mean marginal gaps were $42.95{\pm}6.93{\mu}m$ in the single crown, $43.53{\pm}5.27{\mu}m$ in 2-unit, $53.43{\pm}13.38{\mu}m$ in 3-unit, and $50.85{\pm}8.25{\mu}m$ in 4-unit on each. The marginal gap of mesial and distal surfaces were statistically significant differences between single, 2-unit group and 3-unit, 4-unit group (p<.05) and this results was effected by the span length. The buccal and lingual surfaces were no statistically significant differences within all groups(p>.05). From this results the span length of the zirconia core may have influence on marginal fitness and the marginal gaps were within the clinically allowed range.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.281-287
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• 2012

This experiment was conducted to investigate the effect of various type of Magma seawater (MSW) concentrations on plant growth and useful mineral contents in Bletilla striata. In the RO (Reverse Osmosis) and ED (Electronic Distal) treatment, hardness of medium was poored in 3.0 g/L gelrite but increased in 8.0 g/L plant agar, 38,000 and $2,000g/cm^2$ respectably. We analyzed the morphological and physiological characteristics differences of B. striata treated various MSW. Survival frequency of plant and growth (shoot length, shoot diameter, root length, root diameter, shoot/root ratio) were significantly increased in RO and ED treatment at 50% and 10%, especially. Chlorophyll contents in ED treatments were higher than those in control and RO treatment. The content of strontium (Sr) in 20, 50, 75, 100% ED treatment, were higher than those in the control and RO, ED 1, 5, 10% treatment. These results showed that treatment of ED with the range of 20~100% could be used to supply the strontium enriched orchid plant. It is considered that MSW may be applied for use in Magma seawater to promotion of growth and produced functional plant.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.12-47
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• 2005

First, mice were dosed with 50mg/kg of streptozotocin(STZ) twice every 24 hours to cause high blood-sugar. Then, after three days, mice were injected with 100mg/kg of STZ again. Two different dosages of Saengjihwangeumja-gami were given to the experiment groups: SA group, 15mg/kg/day, and SB group, 90mg/kg/day, in order to determine the effects of Saengjihwangeumja-gami, which has been known to be good for DM(Diabetes Mellitus). By observing weight and blood-sugar level changes, blood tolerance, the numerical value of BUN(Blood Urea Nitrogen) and creatinine in blood, and through light-electronicmicroscopic and immunohistologic investigations of pancreas and kidneys, the following results were obtained: 1. The experiment groups showed a high suppressive effect of weight-loss. 2. The experiment groups' blood-sugar and blood tolerance showed an effective lowering of blood-sugar levels. 3. The experiment groups did not show any noticeable change in the numerical value of BUN and creatinine in blood compared with that of the control groups. 4. The experiment groups showed a higher Insulin positive reaction of pancreatic islets ${/beta}-cell$ than the control groups. 5. The experiment groups showed a higher immuno-reaction against IGF- II than the control groups. 6. Observation of apoptosis of the pancreatic islets showed that the cells of experiment groups were less injured compared with those of the control groups, and fewer apoptag-positive reaction cells were seen in experiment groups than in the control groups. 7. Uunder electron-microscopy, the insulin-containing granules in pancreatic islets ${/beta}-cells$ had increased more in the experiment groups than in the control groups. 8. Under light microscopy, the injury on the inner & outer membrane of the glomerulus and epithelial cells of capillaries and cells among vessels were fewer in the experiment groups than in the control groups. 9. More apoptag-positive reaction cells in the kidney were seen in the control groups than in the experiment groups. 10. PAS-positive reaction substances had increased more in the substrate among the vessels of a glomerulus belonging to the control group than those of the experiment group. 11. Uunder electron-microscopy, the nucleonic membrane, nucleoplasm and mitochondria of proximal and distal renal tubular were more injured in the control groups than in the experiment groups. In conclusion, strong evidence for the efficacy of Saengjihwangeumja-gami in lowering blood-sugar, and in recovery and generation of pancreatic tissues injured by DM was observed. Results suggest Saengjihwangeumja-gami is an effective treatment for DM. Further study of the principles of blood-sugar dropping effects of Saengjihwangeumja-gami are needed, as well as further study of recovery and regeneration of pancreatic tissues injured by DM.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.428-446
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• 1997

Restorative procedures can lead to weakening tooth due to reduction and alteration of tooth structure. It is essential to prevent fractures to conserve tooth. The resistance to fracture of the restored tooth may be influenced by many factors, among these are the cavity dimension and the physical properties of the restorative material. The placement of direct composite resin restorations has generally been found to have a strengthening effect on the prepared teeth. It is the purpose of this investigation to study the relationship between the cavity isthmus and the fracture resistance of a tooth in composite resin restorations. In this study, MO cavity was prepared on maxillary first premolar. Three dimensional finite element models were made by serial photographic method and isthmus(1/4, 1/3, 1/2 of intercuspal distance) were varied. Two types of model(B and R model) were developed. B model was assumed perfect bonding between the restoration and cavity wall and R model was left unfilled. A load of 500N was applied vertically at the first node from the lingual slope of the buccal cusp tip. This study analysed the displacement, 1 and 2 direction normal stress and strain with FEM software ABAQUS Version 5.2 and hardware IRIS 4D/310 VGX Work-station. The results were as follows : 1. Displacement of buccal cusp in R model occurred and increased as widening of the cavity, and displacement in B model was little and not influenced by cavity width. 2. There was a significant decrease of stress resulting in increase of fracture resistance in B model when compared with R model. 3. With the increase of the isthmus width, B model showed no change in the stress and strain. In R model, the stress and strain increased both in the area of buccal-pulpal line angle and the buccal side of marginal ridge, therefore the possibility of crack increased. 4. The stress and strain were distributed evenly on the tooth in B model, but in R model, were concentrated on the buccal side of the distal marginal ridge and buccal-pulpal line angle, therefore the possibility of fracture increased.