• The Journal of Korean Academy of Prosthodontics
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• v.50 no.3
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• pp.191-197
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• 2012

Esthetics is important in restoring maxillary anterior area. Alveolar bone resorption and loss of interdental papilla may be minimized by immediate implantation. Previous studies showed successful results with the immediate implantation in healthy extraction socket, while many of these studies objected the immediate implantation into extraction sites with periapical lesions. Recent studies, however, reported successful results of the immediate implantation into extraction sites with periapical lesions with careful debridement of extraction sockets and general medication of antibiotics prior to implantation. A 73-year-old female visited the department of Prosthodontics in ${\bigcirc}{\bigcirc}$ University Dental Hospital with the chief complaint of fallen post-core and crown on left maxillary incisor. Although the incisor was with vertical root fracture and periapical lesion, the immediate implantation following the extraction of tooth was planned. Thorough socket debridement, irrigation with chlorhexidine, and tetracycline soaking were followed by immediate implantation. The general medication of antibiotics (Moxicle Tab.$^{(R)}$, 375 mg) was prescribed before and after the surgery. Immediate provisional restoration was delivered two days after the surgery, and the definitive metal-ceramic restoration was placed about six months later after reproducing the emergence profile from the provisional restoration. This case presents satisfying result esthetically and functionally upto two years after the placement of prosthesis with the harmonious gingival line and no loss of marginal bone.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.12
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• pp.1005-1011
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• 2016

The fundamental reason for gear noise is transmission error. Transmission error occurs because of STE (static transmission error) and DTE (dynamic transmission error), while a pair of gears is meshing. These errors are generated by the deflection of the teeth and the friction on the surface of the teeth. In addition, the vibration generated by transmission error leads to excited bearings. The bearings support the shafts, and the noise is radiated after exciting the gear casing. The analysis of the contact stress in helical gear tooth flanks indicates that it is due to impact loading, such as the sudden engagement and disengagement of a gear. Stress analysis is performed for different roll positions, in order to determine the most critical roll angle. Dynamic analysis is performed on this critical roll position, in order to evaluate variation in stresses and tooth contact force, with respect to time. In this study, transmission error analysis was implemented on a spur and helical gear with involute geometry and a modified geometry profile. In addition, in order to evaluate the intensity of impact due to sudden engagement and significant backlash, the impact factor was calculated using the finite element analysis results of static and dynamic maximum bending stresses.

• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.1-16
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• 2000

It is difficult to treat the endodontic apical perforation successfully. In this study, we hypothesized that the application of PDGF-BB and IGF-I into periapical perforation site may accelerate periapical healing and lead to bone deposition. And the specificity of osteonectin in periapical healing was investigated. The experiments were performed on the upper and lower 51 premolar teeth of 4 beagle dogs. The pulp chamber of each tooth was opened and the dental plaque was inserted into the canal for developing the periapical lesion for 5 weeks. Then, the roots were artificially perforated at the apex with the number 4 profile of .06 taper. In each step, standard periapical radiographs were taken to compare the size of lesion each other. The radiographs were scanned and analyzed by image analysis system. The mean and standard deviation of periradicular radiolucency ratios were calculated in each group. ANOVA was used for comparison. 51 premolars were grouped into 3 groups; control group, calcium hydroxide-treated group and calcium hydroxide plus growth factors-treated group. In the control group, the apical perforations were not sealed and obturated with gutta-percha and ZOE sealer by lateral condensation technique. In the experimental groups, the apical perforation were sealed with calcium hydroxide and with/without $4{\mu}g$ of PDGF-BB & IGF-I in cellulose gel and obturated by lateral condensation technique. Fluorescent bone markers were used to measure new bone formation. Following 2, 4, 12 weeks after experiment the dogs were sacrificed and histologic sections were prepared. Each tooth block including periapical lesion was sectioned mesiodistally. One half of the sections were decalcified with 6% nitric acid and processed by standard paraffin embedding technique. The sections were stained by hematoxylin and eosin, and immunostained for osteonectin. Histomorphometrical measurement of neoformed bone was performed using a light microscope. And the other half of the sections were prepared by undecalcified preparation, and confocal laser scanning microscopic investigations were done.

• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.1
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• pp.48-60
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• 2021

Patients who have extruded anterior teeth and deep bite with pathologic tooth migration, it is necessary not only periodontal treatment for reduce inflammation, but also orthodontic treatment for intrusion of anterior teeth. However, it is difficult to place the orthodontic brackets due to the deep bite, and there is a problem that the extrusion of the posterior teeth occurs more easily than the intrusion of the anterior teeth biomechanically. In particular, in patients with long face, relative intrusion of the anterior teeth by extrusion of the posterior teeth causes the clockwise rotation of the mandible and makes the facial profile worse. Therefore the biomechanical consideration and appliance design that can block these problems are required from the treatment plan. This is a patient who had a deep overbite with extruded anterior teeth, treated by periodontal treatment and intrusion of mandibular anterior teeth using cute brackes and miniscrews, and resulted in favorable maintenance during 8-year retention.

• Journal of dental hygiene science
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• v.16 no.6
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• pp.415-423
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• 2016

This study examined the relationship between oral health behaviors and in senior citizens to determine how to improve their happiness index. The subjects in this study were 260 senior citizens aged 65 years or older, who resided in North Jeolla Province. A survey was conducted from June 17 to 30, 2016. The happiness index of elderly people who brushed their teeth more often and had dental checkups on a regular basis was significantly higher (p<0.05). Evaluation of subfactors associated with quality of life related to oral health showed significant differences in functional disturbances according to gender, age, the presence or absence of a spouse, and the use or nonuse of dentifrice (p<0.05). Physical pain significantly varied with the presence or absence of a spouse, educational level, monthly mean allowance, and regular dental checkups (p<0.05); significant differences were found in psychological discomfort according to gender, tooth brushing frequency, and regular dental checkups (p<0.05). There were significant differences in declining physical capacity according to gender, age, educational level, and monthly mean allowance (p<0.05); waning mental capacity significantly differed with age, living alone or with another person, the presence or absence of a spouse, and regular dental checkups (p<0.05). The factors that influenced the happiness index in senior citizens were age, living alone or with another person, educational level, monthly mean allowance and the Oral Health Impact Profile score (p<0.05). The study showed that measures are needed to improve the quality of life and happiness index in elderly people, including the development of oral health programs for this population.

• Journal of dental hygiene science
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• v.15 no.5
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• pp.594-602
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• 2015

The purpose of this study was to examine the relationship of oral health status and oral health care to life. The subjects in this study were the patients who visited dental hospitals and clinics in several regions for seven months from March 2013. They got dental checkups, and a survey was conducted. The patients who received general treatment scored highest in Oral Health Impact Profile-14. Among the subfactors, the patients who received general treatment scored higher in functional limitation (8.27), physical pain (7.24), physical restrictions (7.90), social restrictions (7.79), physical limitations (8.14) and social difficulties (8.24). The patients who received orthodontic treatment scored higher in handicap (8.78). All the differences were statistically significant. As for gender gaps, the men scored higher in every factor. By age group, the older patients led a worse quality of life. By occupation, the homemakers mostly led a worse quality of life, and the patients who had no systemic diseases lived a better quality of life. All the differences were significant. Concerning self-rated health status and self-rated oral health state, the patients who found themselves to be in better health and in better oral health led a better quality of life. The differences were significant. Regarding oral health care, the patients who didn't get regular dental checkups and who could visit a dental clinic whenever they had a pain lived a better quality of life. The differences were significant. In terms of oral health status, a higher quality of life was found among the patients who had sound teeth, whose teeth received no sealant treatment, whose teeth received no filling therapy, who had no missing tooth, whose teeth received no prosthetic treatment and who had no dental implants teeth.

• Restorative Dentistry and Endodontics
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• v.33 no.4
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• pp.397-404
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• 2008

The purpose of this study was to evaluate the effects of MTAD, EDTA and sodium hypochlorite(NaOCl) as final irrigants on coronal leakage resistance to Enterococcus faecalis. Forty extracted human maxillary molars were used in this experiment. The teeth were randomly divided into positive control group (Group 1; n = 5), negative control group (Group 2; n = 5) and three experimental groups (n = 30). In Group 3 (n = 10), the root canals were irrigated with sodium hypochlorite. In Group 4 (n = 10) and 5 (n = 10), the root canals were irrigated with sodium hypochlorite and rinsed with EDTA and MTAD, respectively. The teeth in each group were cleaned and shaped to #40 profile with .04 taper, and obturated with gutta-percha and AH-26 root canal sealer. The coronal portion of each tooth was placed in contact with inoculum of Enterococcus faecalis in Brain Heart Infusion (BHI) culture media. Each root tip was placed in a vial containing sterile culture media. The vials were placed in anaerobic chamber and observed everyday for turbidity for 180 days. Statistical analysis was performed using Fisher's Exact Test. After 180 days, Group 3, 4, and 5 showed 7, 4 and 5 leaking samples respectively. The differences in leakage resistance were not statistically significant among Group 3, 4 and 5.

• The korean journal of orthodontics
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• v.47 no.2
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• pp.130-141
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• 2017

The aim of this case report was to describe an innovative orthodontic treatment method that combined surgical and orthodontic techniques. The novel method was used to achieve a positive result in a case of moderate crowding by employing a computer-guided piezocision procedure followed by the use of clear aligners. A 23-year-old woman had a malocclusion with moderate crowding. Her periodontal indices, oral health-related quality of life (OHRQoL), and treatment time were evaluated. The treatment included interproximal corticotomy cuts extending through the entire thickness of the cortical layer, without a full-thickness flap reflection. This was achieved with a three-dimensionally printed surgical guide using computer-aided design and computer-aided manufacturing. Orthodontic force was applied to the teeth immediately after surgery by using clear appliances for better control of tooth movement. The total treatment time was 8 months. The periodontal indices improved after crowding correction, but the oral health impact profile showed a slight deterioration of OHRQoL during the 3 days following surgery. At the 2-year retention follow-up, the stability of treatment was excellent. The reduction in surgical time and patient discomfort, increased periodontal safety and patient acceptability, and accurate control of orthodontic movement without the risk of losing anchorage may encourage the use of this combined technique in appropriate cases.

• Journal of Korean Biological Nursing Science
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• v.22 no.3
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• pp.192-203
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• 2020

Purpose: The purpose of this study was to identify the influencing factors of oral environment and self-care behavior on the oral health-related quality of life in the elderly with diabetes. Methods: The participants were 110 elderly patients with diabetes and follow-up care on their outpatient clinic in D and G city. Data were collected September-December 2018, using questionnaires of the Oral Health Impact Profile (OHIP-49) and Kim's Self-care Behavior, measuring with the tooth-pick (Premiers Dental), Halitosis Checker (HC-212M), and Moisture Checker for Mucus (MCM) for oral environments. The data were analyzed the by independent t-test, oneway ANOVA, Pearson's correlation, and stepwise multiple regression analysis using an IBM SPSS Statistics 25.0 Program. Results: There was positive correlation between oral health-related quality of life and self-care behavior (r= .61, p< .001), negative correlations among halitosis (r = -.34, p< .001), gingival index (r = -.31, p= .001) and plaque index (r = -.32, p= .001). Self-care behavior (β= .46, p< .001), subjective health status (good) (β= .23, p= .002), halitosis (β= -.16, p= .030), and plaque index (β= -.15, p= .041) explained 46.0% of the variance in the oral health-related quality of life. Conclusion: It is necessary to develop nursing care for elderly patients with diabetes that can enhance the self-care behavior and subjective health status, and lower halitosis and plaque index, the factors influencing the oral health-related quality of life in elderly patients with diabetes.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.37.1-37.7
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• 2018

Background: Fibrous dysplasia (FD) is characterized by the replacement of normal bone by abnormal fibro-osseous connective tissue and typically treated with surgical contouring of the dysplastic bone. When dysplastic lesions involve occlusion, not only is surgical debulking needed, orthognathic surgery for correction of dentofacial deformity is mandatory. However, the long-term stability of osteotomized, dysplastic bone segments is a major concern because of insufficient screw-to-bone engagement during surgery and the risk of FD lesion re-growth. Case presentation: This case report reviewed two patients with non-syndromic FD that presented with maxillary occlusal canting and facial asymmetry. Le Fort I osteotomy with recontouring of the dysplastic zygomaticomaxillary region had been performed. The stability of osseous segments were favorable. However, dysplastic, newly formed bone covered the previous plate fixation site and mild bony expansion was observed, which did not influence the facial profile. Including the current cases, 15 cases of orthognathic surgery for FD with dentition have been reported in the literature. Conclusion: The results showed that osteotomy did not appear to significantly reduce the long-term stability of the initial fixation insufficiency of the screw to the dysplastic bone. However, based on our results and those of the others, long-term follow-up and monitoring are needed, even in cases where the osteotomized segment shows stable results.