• The korean journal of orthodontics
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• v.19 no.3
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• pp.137-145
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• 1989

The aim of this investigation was to study the effect of orthodontic force on the flow of gingival crevicular fluid and activities of arylsulfatase and brta-glucuronidase in crevicular fluid. The material consisted of 12 persons between the ages of 13 years and 22 years and all were categorized Class I, 4-4 extraction cases Crevicular fluids were sampled from distal crevis of each canine before treatment (phase 1), after bracketing (phase 2), after application of force (phase 3) and after run out of orthodontic force (phase 4). Crevicular fluid flow did not show any significant changes during the period of treatment. The activities of arylsulfatase increased significantly after setting of orthodontic appliance without application of force, but did not show any significant difference after application of force. The activities of beta-glucuronidase increased significantly after application of orthodontic force and decreased with force deminished. These indicated that beta-glucuronidase was good indicator of bone remodelling resulted from initial orthodontic force.

• Journal of dental hygiene science
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• v.18 no.5
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• pp.319-326
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• 2018

Although scaling is the primary method for improving oral health, it is also associated with dental fear. The objective of this study was to empirically verify whether the use of gel anesthetic within the gingival sulcus during scaling relieves pain and improves other factors. A total of 128 patients scheduled to undergo scaling at a dental clinic of a general hospital located in the Gyeonggi Province, between July 2014 and July 2015, were enrolled in the study. The participants underwent scaling following the application of 20% benzocaine gel or placebo gel anesthetic within the gingival sulcus, and the data was collected using a questionnaire. There was a significant difference in the severity of pain, participant satisfaction, perceived sensitivity, overall discomfort, and fear of scaling between the two groups. The two groups were compared in terms of perceived need for gel anesthesia, willingness to pay for anesthesia costs, and willingness to receive scaling in the future. There were significant differences in all the three parameters depending on whether gel anesthesia was used or not. There were significant differences between the two groups in perceived sensitivity immediately after scaling and one day after scaling, with no difference seen one week after scaling. With regards to overall discomfort over time, there were significant differences between the two groups immediately after scaling. Based on these findings, we expect that application of gel anesthetic within the gingival sulcus during scaling will reduce pain, perceived sensitivity, overall discomfort, and fear of scaling with increased satisfaction.

• Journal of Korean Dental Science
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• v.2 no.1
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• pp.42-47
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• 2009

Objective : The purpose of this study was to evaluate the effects of low level lasers on bone healing and new bone formation around titanium dental implants in canine models. 18 oxidized surface treated implants and a Dens-bio laser were used. Study design : Low level lasers were irradiated with a total of 8J for 4 minutes by pulse wave type and 1 minute by continuous type. For the experimental group, a low level laser was used to irradiate the first premolar implant's insertion area at the time of insertion, a low level laser was used to irradiate the second premolar implant's insertion area daily for one week after implant insertion, and a low level laser was used to irradiate the third molar implant's insertion area daily for 2 weeks postoperatively. At the conclusion of the study, sacrificed tissue sections were made from investing tissue and observed under an optical microscope. Results : The rate of new bone formation around the implant showed no significant difference between the control group and the experimental group. New bone formation rates of the control and experimental group 2 weeks following implant placement were higher than that of immediately after implant placement and 1 week after implant placement. Conclusions : Based on these results, a low-level laser showed no statistically significant increase in bone formation following implant placement.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.4
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• pp.310-319
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• 2006

Submucosal type cleft palate is subdivision of the cleft palate. It is very difficult to find submucosal cleft, because when we exam submucosal type cleft palate patients, it seems to be normal. But in fact, there are abnormal union of palatal muscles of submucosal type cleft palate patients. Because of late detection, the treatment - for example, the operation or the speech therapy - for the submucosal type cleft palate patient usually becomes late. Some patients visited our hospital due to speech disorder nevertheless normal intraoral appearance. After precise intraoral examination, we found out submucosal cleft palate. We evaluated the speech before and after surgery of these patients. In this study, we want to find the objective characteristics of submucosal type cleft palate patients, comparing with the normal and the complete cleft palate patients. Experimental groups were 10 submucosal type cleft palate patients and 10 complete cleft palate patients who got the operation in our hospital. And, the controls were 10 normal person. The sentence patterns using in this study were simple 5 vowels. Using CSL program we evaluated the Formant, Bandwidth. We analized the spectral characteristics of speech signals of 3 groups, before and after the operation. In most cases, the formant scores were higher in experimental groups (complete cleft palate group and submucosal type cleft palate group) than controls. There were small differences when speeching /a/, /i/, /e/ between experimental groups and control groups, large differences when speeching /o/, /u/. After surgery the formant scores were decreased in experimental groups (complete cleft palate group and submucosal type cleft palate group). In bandwidth scores, there were no significant differences between experimental groups and controls.

• Archives of Craniofacial Surgery
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• v.14 no.2
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• pp.119-123
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• 2013

Except for special situations, it is generally agreed that best results in the treatment of facial fractures is expected if reduction is done within the first 2 or 3 weeks after injury. We reduced facial bone fractures at 4 to 7 weeks after trauma. A 44-year-old female patient underwent open reduction for her right zygomaticomaxillary complex fracture at 7 weeks after injury. A 59-year-old female patient underwent surgery for the right mandible body and left parasymphysis fractures at 4 weeks after injury. Using traditional approaches, granulation tissue and callus were removed from the fracture sites, and malunited fracture lines were separated by a small osteotome. We reduced the displaced fractured zygoma and mandible to their normal anatomical positions and fixed them using titanium plates. No complications such as asymmetry, malunion, malocclusion, or trismus were seen. Unfavorable asymmetric facial contours were corrected, and we obtained good occlusion with favorable bony alignment. The functional and aesthetic outcomes were satisfactory. Through removal the callus and limited osteotomy, a successful approach to the previously fractured line was possible, and an exact correction with symmetry was obtained. This method can be a good option for obtaining good mobility and clinical results in treating delayed facial bone fractures.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.516-525
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• 2004

Mandibular symphyseal distraction osteogenesis is an alternative approach for correcting mandibular transverse deficiencies and dental crowding. The traditional approaches for these are extraction of teeth and arch expansion with traditional orthodontic treatment. Also extractions are usually unavoidable in patients with severe crowding. The purpose of this study is to evaluate the effect of mandibular symphyseal distraction osteogenesis by use of tooth-borne expansion appliance. All of 12 patients had been performed distraction osteogenesis. The surgical procedures were accomplished under local anesthesia and intravenous sedation in an ambulatory surgical setting using a routine distraction protocol. The latency period was 5 days or 7 days after symphyseal osteotomies. The rate & rhyth is a intermittent, 0.75mm or 1.0 mm per day and stabilized for 6, 8 weeks after distraction. The time of orthodontic tooth movement after distraction was variable from 2 weeks to 8 weeks (mean 3 weeks). All patients had been evaluated with study casts, plain periapical films, panorama radiograms before & after surgery. Mandibular symphyseal distraction osteogenesis increased mandibular arch width and corrected dental crowding, with paralleling tooth-borne movement, without proclination of the mandibular incisors.

• The Korean Journal of Pain
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• v.13 no.1
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• pp.31-37
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• 2000

Background: Recent studies suggested that a preoperative block of N-methyl-D-aspartate (NMDA) receptors with NMDA antagonists may reduce postoperative pain. In this double-blind study, magnesium sulfate, a natural NMDA receptor antagonist, was administered preoperatively to investigate the effects of magnesium sulfate on postoperative pain and pulmonary function. Methods: Seventy patients who were to undergo gastrectomy under general anesthesia were randomly assigned to one of three groups. Groups 2 and 3 received intravenous magnesium, preoperatively (Group 2: 50 mg/kg bolus, 7.5 mg/kg/hr for 20 hr, Group 3: 50 mg/kg bolus, 15 mg/kg/hr for 20 hr). Group 1 received normal saline as the control group. Visual analog scale (VAS) for postoperative pain and mood, cumulative analgesic consumption, recovery of pulmonary function and side effects were evaluated at 6, 24, 48 and 72 hours after the operation. Results: In Groups 2 and 3, plasma concentration of magnesium were significantly higher than in Group 1 at 6 and 20 hours after infusion (P<0.05). There were no significant differences in the analgesic consumption, and recovery of pulmonary function and the incidence of side effects at 6, 24, 48 and 72 hours after the operation among the three groups. In Group 3, pain scores at rest measured 24 and 48 hours after operation were lower than the control group, and pain scores when deep breathing were significantly lower than the control group at postoperative 6, 24, 48, and 72 hours. Conclusions: We conclude that intravenous infusion of greater amount of magnesium has little effectiveness in reducing postoperative pain. However, further studies are needed to characterize the clinical significance of these effects on postoperative pain.

• Korean Journal of Clinical Pharmacy
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• v.27 no.4
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• pp.250-257
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• 2017

Objective: The prevalence rate of osteoarthritis in Koreans aged 50 years or older is 14.3%, and the total amount of medical costs is more than KRW 1 trillion. Recently, the reimbursement guidelines for osteoarthritis treatment have changed. Methods: In this study, we sought to describe prescription patterns of nonsteroidal anti-inflammatory drugs (NSAIDs) and gastro-protective agent (GPA) and analyze the clinical and economic impacts of the new policy using the national health insurance claims data. The incidence of upper gastrointestinal adverse event by policy change was identified through the odds ratio, and changes in medicine and medical costs related to osteoarthritis through mean and median. Results: There were 204,552 patients before the reimbursement guidelines relaxation and 239,710 after it, a 17.2% rise. The prescription ratio was 3.3% for the patients prescribed with COX-2 selective NSAIDs alone and 1.3% for those with both COX-2 selective NSAIDs and GPA combination before the reimbursement guidelines relaxation. The reimbursement guidelines relaxation significantly increased their ratios to 6.9% and 2.8%, respectively. Gastrointestinal adverse events significantly reduced by 1.21%p after reimbursement guidelines relaxation. The average medicine cost per person increased significantly to KRW 140,291 from KRW 137,323 after the reimbursement guidelines relaxation, while the average medical cost per person slightly decreased from KRW 311,605 to KRW 310,755 after the relaxation, showing no meaningful difference. Conclusion: The reimbursement guidelines relaxation may influence on decreasing the upper gastrointestinal adverse event, increasing the medicine costs and maintaining the medical costs for osteoarthritis.

• Journal of Korean Neurosurgical Society
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• v.50 no.6
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• pp.503-506
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• 2011

Objective : The aim of this study was to assess the safety and efficacy of radiation-sterilized allografts of iliac bone and fascia lata from cadaver specimens to repair skull base defects after transsphenoidal surgery. Methods : Between May 2009 and January 2010, 31 consecutive patients underwent endonasal transsphenoidal surgery and all patients received sellar reconstruction using allografts following tumor removal. The allografts were obtained from the local tissue bank and harvested from cadaver donors. The specimens used in our approach were tensor fascia lata and the flat area of iliac bone. For preparation, allografts were treated with gamma irradiation after routine screening by culture, and then stored at $-70^{\circ}C$. Results : The mean follow-up period after surgery was 12.6 months (range, 7.4-16 months). Overall, postoperative cerebrospinal fluid (CSF) leaks occurred in three patients (9.7%) and postoperative meningitis in one patient (3.2%). There was no definitive evidence of wound infection at the routine postoperative follow-up examination or during re-do surgery in three patients. Postoperative meningitis in one patient was improved with the use of antibiotics and prolonged CSF diversion. Conclusion : We suggest that allograft materials can be a feasible alternative to autologous tissue grafts for sellar reconstruction following transsphenoidal surgery under selected circumstances such as no or little intraoperative CSF leaks.

• Tribology and Lubricants
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• v.24 no.4
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• pp.190-195
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• 2008

Many researchers have tried to improve the tribological characteristics of lubricant by adding various nano particles in the base lubricant. But the reliability evaluation of the lubricants are rarely performed in its real operation condition. In this study, the physical property and the tribological characteristics of the graphite nano lubricant were evaluated and compared with raw lubricant after thermal degrading. In order to evaluate the tirbological characteristics, the disk-on-disk tribotester was adopted to measure the friction coefficient of the graphite nano lubricants. Also the temperature variations of friction surfaces were measured by the thermocouple installed on the fixed plate in the test chamber of the tribotester. The kinematic viscosity was measured using a capillary viscometer on the temperatures of 40, 60 and $80^{\circ}C$. The results showed that the graphite nano lubricant had lower friction coefficient and less wear on the friction surfaces than raw lubricant. After thermally degrading, the friction coefficients of graphite nano lubricant increased, but the friction coefficients after thermal degradation were still maintained lower than those of raw lubricant.