• Journal of Korean society of Dental Hygiene
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• v.24 no.2
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• pp.121-130
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• 2024

Objectives: This study aimed to develop a virtual reality (VR)-based oral strength training program and apply it to older adults to assess improvements in oral function. Methods: The oral strength training was conducted 12 times over 6 weeks, from late August to early October 2023, at the participants' institution. Each session lasted approximately 60 minutes. Forty-one participants aged 65 and older were randomly assigned to either the intervention or control group. Results: Following the VR-based oral muscle strength training, the O'Leary index decreased by 0.42 (p<0.01), and the Löe & Silness index decreased by 1.11 (p<0.01). Additionally, there was a 1.24 reduction in tongue tie (p<0.01) and a 0.55 increase in salivation (p<0.05). Post hoc comparisons revealed significant differences between the two groups in gingival bacterial film (p<0.001), gingivitis (p<0.001), and tongue plaque (p<0.01). Conclusions: The study found that VR-based oral muscle strength training can improve oral health among older adults. Therefore, the VR-based oral muscle strength training program developed in this study could be beneficial in health promotion programs for the elderly.

• Journal of Periodontal and Implant Science
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• v.54 no.2
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• pp.75-84
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• 2024

Purpose: This study investigated the relationship between the number of days that hospital visits were postponed and changes in clinical parameters due to the spread of coronavirus disease 2019 (COVID-19), after the Japanese government declared a state of emergency in April 2020. Methods: Regarding the status of postponement of appointments, we analyzed the patients who had visited the Nihon University Hospital at Matsudo for more than 1 year for supportive periodontal therapy (SPT) and classified them into low-, moderate- and high-risk subgroups according to the periodontal risk assessment (PRA). Clinical parameters for periodontal disease such as probing depth (PD), full-mouth bleeding score (FMBS), full-mouth plaque score, periodontal inflamed surface area (PISA), and periodontal epithelial surface area (PESA) were analyzed in 2 periods, from October 2019 to March 2020 and after April 2020. Correlation coefficients between days of deferral and the degree of changes in clinical parameters were calculated. Results: The mean age of the 749 patients was 67.56±10.85 years, and 63.82% were female. Out of 749 patients, 33.24% deferred their SPT appointments after April 2020. The average total of postponement days was 109.49±88.84. The number of postponement days was positively correlated with changes in average PD (rs=0.474) and PESA (rs=0.443) in the high-risk subgroup of FMBS, and average PD (rs=0.293) and PESA (rs=0.253) in the highrisk subgroup of tooth number (TN). Patients belonging to the high-risk subgroups for both FMBS and TN had a positive correlation between postponement days and PISA (rs=0.56). Conclusions: The findings, the spread of COVID-19 appears to have extended the visit interval for some SPT patients. Moreover, longer visit intervals were correlated with the worsening of some clinical parameters for SPT patients with high PRA.

• Journal of the Korean Society of Radiology
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• v.85 no.2
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• pp.297-307
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• 2024

Coronary artery disease (CAD) narrows vessel lumens at the sites of atherosclerosis, increasing the risk of myocardial ischemia or infarction. Early and accurate diagnosis of CAD is crucial to significantly improve prognosis and management. CT angiography (CTA) is a noninvasive imaging technique that enables assessment of vascular structure and stenosis with high resolution and contrast. Coronary CTA is useful in the diagnosis of CAD. Recently, the CAD-reporting and data system (CAD-RADS), a diagnostic classification system based on coronary CTA, has been developed to improve intervention efficacy in patients suspected of CAD. While the CADRAD is based on CTA, it includes borderline categories where interpreting the coronary artery status solely based on CTA findings may be challenging. This review introduces CTA findings that fall within the CAD-RADS categories that necessitate additional tests to decide to perform invasive coronary angiography and discusses appropriate management strategies.

• Dementia and Neurocognitive Disorders
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• v.23 no.1
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• pp.22-29
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• 2024

Background and Purpose: Alzheimer's disease (AD) is a neurodegenerative disease characterized by a progressive decline in cognition and performance of daily activities. Recent studies have attempted to establish the relationship between AD and sleep. It is believed that patients with AD pathology show altered sleep characteristics years before clinical symptoms appear. This study evaluated the differences in sleep characteristics between cognitively asymptomatic patients with and without some amyloid burden. Methods: Sleep characteristics of 76 subjects aged 60 years or older who were diagnosed with subjective cognitive decline (SCD) but not mild cognitive impairment (MCI) or AD were measured using Fitbit^® Alta HR, a wristwatch-shaped wearable device. Amyloid deposition was evaluated using brain amyloid plaque load (BAPL) and global standardized uptake value ratio (SUVR) from fluorine-18 florbetaben positron emission tomography. Each component of measured sleep characteristics was analyzed for statistically significant differences between the amyloid-positive group and the amyloid-negative group. Results: Of the 76 subjects included in this study, 49 (64.5%) were female. The average age of the subjects was 70.72±6.09 years when the study started. 15 subjects were classified as amyloid-positive based on BAPL. The average global SUVR was 1.598±0.263 in the amyloid-positive group and 1.187±0.100 in the amyloid-negative group. Time spent in slow-wave sleep (SWS) was significantly lower in the amyloid-positive group (39.4±13.1 minutes) than in the amyloid-negative group (49.5±13.1 minutes) (p=0.009). Conclusions: This study showed that SWS is different between the elderly SCD population with and without amyloid positivity. How SWS affects AD pathology requires further research.

• Journal of Korean society of Dental Hygiene
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• v.24 no.4
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• pp.291-300
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• 2024

Objectives: To develop a program that combines the oral health promotion program for the elderly and to investigate the effect of improving oral function by applying the oral health promotion program to elderly people using welfare facilities. Methods: From June to October 2022, a total of 29 elderly individuals utilizing welfare facilities in the Gyeongnam region were recruited. The control group underwent surveys and objective oral health assessments. The experimental group participated in an oral health promotion program, consisting of oral functional rehabilitation exercises and expert oral health management, conducted once a week for 8 weeks at the facilities. Objective oral health assessments were conducted before, during (at 4 weeks), and after (at 8 weeks) the intervention period for both groups. Results: As a result of the oral health promotion program, it was confirmed that there was an improvement effect in bad breath (p<0.001), saliva secretion amount (p<0.001), orbicularis oculi muscle (p<0.001), and plaque index (p<0.001). Conclusions: A revitalization plan is needed so that the efficient oral health promotion program for the elderly can be reflected as a systematic and professional community care oral health management program.

• Korean Journal of Veterinary Research
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• v.9 no.1
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• pp.23-62
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• 1969

Throughout the studies the following experimental results were obtained and are summarized: 1. Multiplication of agents in primary cell cultures of both GF classical and CR-64 acute strain of Marek's disease infected chicken kidneys was accompanied by the formation of distinct transformed cell foci. This characteristic nature of cell transformation was passaged regularly by addition of dispersed cell from infected cultures to normal chicken kidney cell cultures, and also transferred was the nature of cell transformation to normal chick-embryo liver and neuroglial cell cultures. No cytopathic changes were noticed in inoculated chick-embryo fibroblast cultures. 2. The same cytopathic effects were noticed in normal kidney cell monolayers after the inoculation of whole blood and huffy coat cells derived from both forms of Marek's disease infected chickens. In these cases, however, the number of transformed cell foci appearing was far less than that of uninoculated monolayers prepared directly from the kidneys of Marek's disease infected chickens. 3. The change in cell culture IS regarded as a specific cell transformation focus induced by an oncogenic virus rather than it plaque in slowly progressing cytopathic effect by non-oncogenic viruses, and it is quite similar to RSV focus in chick-embryo fibroblasts in many respects. 4. The infective agent (cell transformable) were extremely cell-associated and could not be separated in an infective state from cells under the experimental conditions. 5. The focus assay of these agents was valid as shown by the high degree of linear correlation (r=0.97 and 0.99) between the relative infected cell concentration (in inoculum) and the transformed cell foci counted. 6. No differences were observed between the GF classical strain and the CR-64 acute strain of Marek's disease as far as cell culture behavior. 7. Characterization of the isolates by physical and chemical treatments, development of internuclear inclusions in Infected cells, and nucleic acid typing by differential stainings and cytochemical treatments indicated that the natures of these cell transformation agents closely resemble to those described fer the group B herpes viruses. 8. Susceptible chicks inoculated with infected kidney tissue culture cells developed specific lesions of Marek's disease, and in a case of prolonged observation after inoculation (5 weeks) the birds developed clinical symptoms and gross lesions of Marek's disease. Kidney cell cultures prepared from those inoculated birds and sacrificed showed a superior recovery of cell transformation property by formation of distinct foci. 9. Electron microscopic study of infected kidney culture cells (GF agent) by negative staining technique revealed virus particles furnishing the properties of herpes viruses. The particle was measured about $100m{\mu}$ and, so far, no herpes virus envelop has been seen from these preparations. 10. No relationship of both isolates to avian leukosis/sarcoma group viruses and PPLO was observed.

• The korean journal of orthodontics
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• v.36 no.4
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• pp.251-262
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• 2006

Objective: The purpose of this study was to compare the bacterial flora at the peri-implant sulcus of the orthodontic mini-implant placed in the alveolar mucosa with the bacterial flora at the adjacent healthy gingival sulcus. Methods: Two plaque samples from 7 patients were collected by inserting paper points into the sulcus between the mini-implant and ligature wire connected to the mini-implant head and inflamed alveolar mucosa, and from the gingival sulcus of a healthy tooth adjacent to the mini-implant. Results: Using 16S rDNA clone library, the 24 kinds of bacteria including Haemophilus aphrophilus, Sphingomonas species, Capnocytophaga species, Prevotella melaninogenica, Lachnospiraceae species, Porphyromonas species, Neisseria flava were identified only from the sulcus around the mini-implant. These bacteria constituted only 9.2% of total clones, and the bacteria identified from both the sulcus around mini-implants and the gingival sulcus constituted 80.4% of total clones. Of these bacteria, clones of Prevotella species, Atopobium rimae, Veillonella species, Streptococcus intermedius/constellatus, Streptococcus salivarius were more frequently isolated from the peri-implant sulcus. Conclusion: This study suggests that a broad epidemiological study is needed to find causative bacteria which induce inflammation from the peri-implant sulcus.

• The korean journal of orthodontics
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• v.31 no.2 s.85
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• pp.173-185
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• 2001

The orthodontic osseointegrated titanium implant, a kind of intraoral skeletal anchorage can be an alternative to tooth-borne anchorage, in case that the conventional tooth-borne anchorage is not available or the anchorage is critical. This study was conducted to elucidate the effect of early loading on the osseointegration of the orthodontic titanium implant and the healing process of the impaired bone at the site of implant after removing it. In two adult beagle dogs24 osseointegrated titanium implants were inserted into the alveolar bone, with 12 implants placed in each dog. In dog1, 6 out of 12 implants were loaded with 200-300gm of force immediately after placing, and the remaining 6 implants were not loaded for 4weeks. In dog2, all 12 implants had healing period of 4weeks, and then were loaded with 200-300gm of force for another 4weeks. Following an observation period of 4 and 8 weeks, the animals were sacrificed. Then the implants and the surrounding bone of dog1 and dog2 were removed, respectively. Undecalcified sections along the long axis of implant were made and the degree of osseointegration was examined under the light microscope. The results were as follows. 1. In the histologic features of tissues around implants anchored in dog1, there was no difference between immediately loaded implants and unloaded implants. Immature woven bone was ingrowing into the thread spaces from the original compacta and in direct contact with the implant surface in part. 2. The premature loading just after 4weeks healing period did not halt the progress of the osseointegration between bone and implant surface. The woven bone around the implants was maturing into the lamellar bone which resembled the structure of the original compacta at the end of 8weeks observation period. 3. Most implants with the inflammed surrounding mucosa were lost or mobile. The mobile implants were encapsulated by fibrous connective tissue which separated the implant surface from the bone. 4. The impaired bone at the site of the implant failed to anchor was showing recovery without inflammatory reaction 2weeks after removing, with the immaure woven bone lined by active osteoblasts and osteoid. Based on the results of this study, the integration of this orthodontic implant seemed to be impaired by the inflammation of the tissue surrounding the Implant rather than by early loading on implant, and increased with time lapsed after placing the implant. The use of implant described in this report can be recommended as an orthodontic anchorage unit immediately after insertion under the careful control of orthodontic force applied and plaque.

• Journal of dental hygiene science
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• v.8 no.3
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• pp.123-129
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• 2008

The purpose of this study was to investigate the actual conditions of the subjective oral malodor perception of the survey subjects. Through the subjective questionnaire method over about 3 months from June to August in 2007, the data was collected targeting 275 adults. Statistical methods used were Chi-square test, Fisher's exact test and One-way ANOVA. And, the following results were obtained. 1. When having seen the ratio of those who were conscious of oral malodor, the adults, who responded with saying of feeling oral malodor at present and at ordinary times, accounted for 68.4% and 79.3%, respectively. And, the adults, who responded with saying of not feeling, were indicated to be 31.6%(at present) and 20.7%(at ordinary times), respectively. 2. Almost 83.5% of total people answered that they had most severe oral malodor at the time of awakening and 51.9% of subjects answered tongue contributed to the their oral malodor. 3. About the type of oral malodor, although 37.2% of the group thought the type of oral malodor was a food smell and fetid smell was second general burning smell occurred the time of hunger(22.5%). 4. In the answers of hoping for treatment of oral malodor, 66.9% of the people showed positive response to dental treatment for controlling their oral malodor. Especially 7.3% of subjects showed very big desire for treatment. 5. In the level of oral malodor that is felt now according to the time of a meal, the case of within 1 hour after having a meal was responded to be not felt the oral malodor with 44.7%. And, there was response with saying of not feeling oral malodor in 37.6% as for 1-2 hours, 16.3% as for 2-3 hours, 14.8% as for 3-4 hours, and 23.7% as for more than 4 hours. Thus, the level of oral malodor according to the time of a meal showed the statistically significant difference(p<0.01). Through the results of this study, it could be known about whether or not being conscious of oral malodor in general people, the main cause and region for oral malodor, the importance and practicing method of tongue brush through literature. Accordingly, there is necessity of further researching and comparing whether or not being conscious of oral malodor by diversely surveying relevancy with factors of causing oral malodor based on the objective oral malodor measurement value. The future diverse researches are thought to be necessarily performed in order to prevent or reduce oral malodor.

• Journal of Korean society of Dental Hygiene
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• v.8 no.2
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• pp.39-51
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• 2008

The research was conducted to 100 child patients selected by random sampling, which got a Dentocult-SM test in the first visit and then was being continuously managed, out of child patients of a pediatric clinic located in Gyeonggi-do. The period of there search is one year from June 2007 to May 2008, Using Dentocult-SM test, we analyzed the correlation between the distribution of dental plaque, a streptococcus mutans in saliva and condition of dental caries cavity in the teeth of child patients, then we measured the distribution of a streptococcusmutans. According to SM score, we applied incremental oral heath care for child patients to clinical and obtained the following results, 1. In terms of the age of child patients in research, the number of 3 years old patients was 29(lst ranked), the number of 2 years old patients was 28(2nd ranked). 2. The result of SM score showed that female child patients(52.0%) was higher than male ones in negative, male child patients(52.0%) was higher than female ones in mild, female child patients(68.2%) was higher than male ones in moderate, male child patients(57.1%) was higher than female ones in severe. 3. At the first visit, the SM score showed statistically remarkable difference between dt and dmft. We can also confirm the average of severe is the highest. 4. At the second visit, the SM score showed statistically remarkable difference among dt, ft, and dmft index We can also confirm the average of severe is the highest. 5. At the third visit, The SM score showed statistically remarkable difference among dt, ft, and dmft index We can also confirm the average of severe is the highest. 6. The comparison of dmft index differences to SM score showed statistically no remarkable difference in incremental oral heath care for negative and mild, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences in moderate and severe. 7. The comparison of dt index differences to SM score showed statistically no remarkable difference in incremental oral heath care for negative, mild, and moderate, In addition to that, we can con firm that the incremental oral heath care makes statistically remarkable differences in severe. 8. The comparison of mt index differences to SM score showed statistically no remarkable difference in incremental oral heath care for mild and moderate, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences m severe. 9. The comparison of ft index differences to SM score showed statistically no remarkable difference in incremental oral heath care for mild, In addition to that, we can confirm that the incremental oral heath care makes statistically remarkable differences in negative, moderate, and severe. 10. According to the comparison of dmft index to the age, the 4 years old patients showed the highest number(5.50 in the first visit and 6,08 in the second one). In the third visit, the 6 years old patients showed the highest number(7.00). By the above results, we can find that the incremental oral heath care by SM score makes the results of oral care better. Therefore, the improvement or maintenance in oral health of child patients needs continuing personal oral health management and regular systematic management focused on prevention by the specialist.