• Journal of Korean society of Dental Hygiene
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• v.18 no.1
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• pp.19-29
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• 2018

Objectives: Despite a rise of an interest in tooth whitening, diverse problems are being caused in case of hydrogen peroxide that is being used as a tooth bleaching agent. Thus, the aim was to examine tooth whitening effectiveness using natural products as a plan for supplementing this. Methods: As a result of having measured a tooth color through using VITA Easyshade V after having developed toothpaste with the application of extracts such as Citrus Peels, Mulberry (Morus alba L.) Root Bark, strawberry, and lemon, and then having used it for 10 weeks, they are as follows. Both upper and lower 6 anteriors mostly got brighter. Results: A statistically significant difference was shown especially in the right canine (p=0.015), in the right central incisor (p=0.007), and in the left central incisor (p<0.001). In consequence of having measured a color change, the tooth got brighter gradually in the higher extract content and in the lengthier use time. In case of canine, it got less bright compared to other teeth. In the outcome of evaluating sensuality, most of the questions were indicated to be high in case of using a whitening toothpaste for 10 weeks. But in what "there is no stickiness in the mouth, the stickiness was more felt in the use up to 5 weeks, but was improved in 10 weeks. Conclusions: The bleaching effectiveness was proved by developing a toothpaste with the application of natural extracts. A short-term effect cannot be seen like a whitening agent of using hydrogen peroxide. But there is a continuous effect in consideration of tooth-brushing more than 3 times a day.

• The Korean Journal of Physiology and Pharmacology
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• v.17 no.2
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• pp.121-125
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• 2013

The purpose of this study is to investigate the antinociceptive effects of ginsenosides on toothache. c-Fos immunoreactive (IR) neurons were examined after noxious intrapulpal stimulation (NS) by intrapulpal injection of 2 M KCl into upper and lower incisor pulps exposed by bone cutter in Sprague Dawley rats. The number of Fos-IR neurons was increased in the trigeminal subnucleus caudalis (Vc) and the transitional region between Vc and subnucleus interpolaris (Vi) by NS to tooth. The intradental NS raised arterial blood pressure (BP) and heart rate (HR). The number of Fos-IR neurons was also enhanced in thalamic ventral posteromedial nucleus (VPMN) and centrolateral nucleus (CLN) by NS to tooth. The intradental NS increased the number of Fos-IR neurons in the nucleus tractus solitarius (NTS) and rostral ventrolateral medulla (RVLM), hypothalamic supraoptic nucleus (SON) and paraventricular nucleus (PVN), central cardiovascular regulation centers. Ginsenosides reduced the number of c-Fos-IR increased by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Naloxone, an opioid antagonist, did not block the effect of ginsenoside on the number of Fos-IR neurons enhanced by NS to tooth in the trigeminal Vc and thalamic VPMN and CLN. Ginsenosides ameliorated arterial BP and HR raised by NS to tooth and reduced the number of Fos-IR neurons increased by NS to tooth in the NTS, RVLM, hypothalamic SON, and PVN. These results suggest that ginsenosides have an antinociceptive effect on toothache through non-opioid system and attenuates BP and HR increased by NS to tooth.

• Journal of the Korea Convergence Society
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• v.7 no.5
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• pp.127-134
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• 2016

This study aims to investigate the factors affecting tooth loss and the association between smoking and tooth loss, by using the forth Korea National Health and National Examination Survey(2007-2009) of 1,565 elderly people over 65 years old. In terms of the characteristics, as age increases, tooth loss increases. In particular, according to the results of the analysis that identify the correlation between smoking to gender, socio-economic status and dental visiting patterns after correcting socio-economic factors and behavior, it is clear that male's tooth loss is higher than female's in current smoking and tooth loss is caused highly in the lower socio-economic status. In the dental visiting patterns, tooth loss is high when visiting more than twice a year. Therefore, it seems to need a preventive non-smoking policy at the level of dental services through further studies.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.1
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• pp.25-33
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• 2017

The lower $2^{nd}$ molar eruption is beginning to mesiolingually, then rotate to distobuccally so it has a tendency to be tilted and impacted mesially. Signs and symptoms of impacted $2^{nd}$ molar are similar to impacted $3^{rd}$ molar's. However, treatment plan for impacted $2^{nd}$ molar is different from that of impacted $3^{rd}$'s. The former is the preservation and uprighting of $2^{nd}$ molar so that it could act to recovery of mastication, symmetrical facial growth, maintaining the symmetry of dental arch, stable occlusion, while the latter is the extraction of tooth. If the uprighting treatment is planned, most proper protocol of treatment and the additional treatment opition should be applied with consideration for it's crown exposure, present of $3^{rd}$ molar which interrupt the uprighting process, extrusion of opposite tooth. Although it could not improve the esthetic result, it could prevent many dental problems. Therefore, uprighting for impacted lower $2^{nd}$ molar is meaningful treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.6
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• pp.289-291
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• 2013

Moyamoya disease is a rare neurovascular disorder that involves constriction of certain arteries in the brain. In patients with moyamoya disease, it is very important to prevent cerebral ischemic attacks and intracerebral bleeding caused by fluctuating blood pressure and increased respiration. A 40-year-old woman with moyamoya disease was scheduled for extraction of her right upper and lower impacted wisdom teeth. Her lower impacted wisdom tooth was situated close to the inferior alveolar nerve. We decided to continue her oral antiplatelet therapy and planned intravenous sedation with analgesic agents administered approximately five minutes prior to extraction of the root of the mandibular wisdom tooth. Oral analgesic medications were regularly administered postoperatively to alleviate pain and anxiety. During the perioperative period, no cerebrovascular event occurred, and the wisdom teeth were successfully extracted as per the planned procedure. It is thought that the perioperative risks of wisdom tooth extraction in patients with moyamoya disease can be minimized with the use of our protocols.

• Journal of Oral Medicine and Pain
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• v.20 no.1
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• pp.217-228
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• 1995

For the purpose of estimating the sex and age in the remains of Catholic martyrs, the authors investigated size, shape and attrition of teeth, morphology of pulp cavity, and the changes of jaws. The 22 teeth, upper and lower jaws, the 23 teeth, upper and lower jaws, the 6 teeth and the 1 tooth were referred from The Pusan Research Institute for Church History in Pusan Catholic Parish. The results were as follows : 1. The 22 teeth, upper and lower jaws presumed to be Lee, Kwan Bok were evaluated to be in the latter half of female thirties. 2. The 23 teeth, upper and lower jaws presumed to be Kim, So ja, Maria were evaluated to be in the middle of male thirties. 3. The 6 teeth presumed to be lee, Jung Suk were evaluated to be in the earlier half of male forties. 4. The 1 tooth presumed to be Lee, Sam jo was evaluated to be in the latter half of male forties.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.4
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• pp.103-112
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• 2017

Purpose : This study was conducted to improve cognitive oral healthcare care by analyzing the correlation between oral health behavior and oral health status Korean adolescents. The subjects were 65,528 youths in 798 schools monitored in the Twelfth Korea Youth Risk Behavior Web-based Survey in 2016. Methods : The general characteristics consisted of 9 items including sex, grade, and academic performance. The academic performance and economic status were restructured into "upper, middle, lower". Subjective health perception and subjective oral health perception were reorganized as "health", "normal", "no health". The sub-areas of oral health behavior include five times of daily brushing during the day yesterday. The number of brushing times was "0", "1-2", "3", "more than 4" After lunch at school, brushing was restructured as "always," "sometimes," "not." The oral health status subscale consisted of 6 items including tooth breakage and toothache at the time of eating. Result : Tooth fracture(43.7 %), pain in mastication(43.7 %), tooth tingling(47.4 %), gum pain and bleeding(45 %), pain in buccal mucosa(43.8 %) and halitosis(46.6 %) were rare in adolescent having healthy oral health status cognitively(P<.001). Nosymptom adolescents without dental sealant showed low tooth fracture(0.64 times), pain in mastication(0.67 times), tooth tingling(0.59 times), gum pain and bleeding(0.84 times), pain in buccal mucosa(0.76 times), and halitosis(0.90 times). Nosymptom adolescents without scaling showed low tooth fracture(0.88 times), pain in mastication(1.03 times), tooth tingling(0.82 times), gum pain and bleeding(0.64 times), pain in buccal mucosa(0.70 times) and halitosis(0.82 times). Conclusion : This study revealed that oral health status is correlated with oral health behavior. Development of educational media and program, and aggressive promotion required to establish oral health Korean adolescent.

• Tribology and Lubricants
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• v.34 no.5
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• pp.183-190
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• 2018

Tilting pad journal bearing is widely used for steam turbines because of its excellent dynamic stability. As the turbine capacity increases, power loss in the bearings becomes a matter of concern. Power loss in tilting pad journal bearings can be reduced by increasing the bearing clearance and reducing the pad arc length. In this study, the tilting pad journal bearing is tested by changing the seal tooth clearance to verify the static characteristics of the bearing. Bearing power loss and bearing metal temperature are evaluated to compare the bearing's performance and reliability for several test cases. The test bearing is a tilting pad journal bearing with 300.62mm inner diameter and 120.00mm active length. The bearing power loss, its metal temperature, and oil film thickness are measured and evaluated based on the rotor's rotational speed, oil flow rate, and bearing load. Test results show that a tilting pad journal bearing with large seal tooth clearance has 40% lower power loss compared with a bearing with a small seal tooth clearance. As the seal tooth clearance is increased, the power loss of the tilting pad journal bearing decreases. However, with respect to the bearing metal temperatures, a detuning point is observed that makes the minimum bearing metal temperature. Moreover, as the seal tooth clearance is increased, the oil film thickness increases due to high viscosity.

• The Journal of Korean Academy of Prosthodontics
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• v.27 no.2
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• pp.79-100
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• 1989

The Purpose of this study was to investigate material differences in stress transmission among various artificial teeth and denture base materials. For this study, a two-dimensional finite element model and a two-dimensional photoelastic model of a mandible with complete denture were made. A resin tooth and a porcelain tooth were used as artificial teeth, and a resin base, a metal lined base, and a soft-liner lined base were used as denture bases. An occlusal load was applied and principal stresses generated in the supporting tissues were compared. To test the impact stress transmission, strain gauge attached to the denture base specimens made of the different materials were made in thick and thin groups. Voltage outputs from hitting the specimen with a steel ball were compared. The results were as follows : 1. In FEM, increasing the mucosal thickness reduced the maximum principal stresses in the supporting tissues, but altering the tooth materials and the base materials induced no difference in the stresses. 2. In photoelastic model study, no difference in fringe order among the specimens were observed, but the thick mucosa group and the soft-liner lined group revealed a more uniform distribution of the load. 3. In strain measuring, the impact force transmission was highest in the soft-liner lined group, and was the lowest in the metal lined group(p<0.01). 4. In the thin group using the resin base, the porcelain tooth showed higher impact stress transmission than the resin tooth(p<0.01), but no difference was observed between them in the thick group. In the soft-liner lined group, the porcelain tooth showed higher impact stress transmission than the resin tooth(p<0.01), but no difference was observed between them in the metal lined group. 5. The thick group showed lower impact stress transmission than the thin group(p<0.01).

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.2
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• pp.86-90
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• 2023

Objectives: An ectopic tooth is a rare eruption of a tooth out of the normal dental apparatus and occurs commonly with the third molar. Thus, in this study, we reported a case series of ectopic teeth in rare jaw locations and highlight the associated pathology and our experience in the surgical management. Patients and Methods: All cases of ectopic tooth managed at the Department of Oral and Maxillofacial Surgery, University of Maiduguri Teaching Hospital from January 2011 to December 2020 were reviewed. The information retrieved includes biodata, location of the ectopic tooth, signs, symptoms, type of tooth and associated pathology, surgical approach and complications. Results: Ten cases of ectopic teeth were identified over the study period. This comprised 80.0% males with a mean age was 23.3 years. The antrum and lower border of the mandible accounted for 50.0% and 40.0% of the ectopic locations, respectively. Dentigerous cyst was the most associated pathology (70%) and usually presented with pain and swelling. Surgical intervention predominantly via the intraoral route was performed if indicated. Conclusion: Ectopic teeth are rare and not always associated with pathology. A high index of suspicion and radiological investigation are necessary for diagnosis. A more extensive multi-center study is however recommended to determine the prevalence of ectopic teeth other than the third molar.