• The Journal of Korean Academy of Prosthodontics
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• v.32 no.2
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• pp.235-248
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• 1994

There were many studies that distribute the partial edentulous states and examine the removable partial denture designs in the planning of removable partial denture treatment. This study was performed in the point of removable partial denture prescription to evaluate partial edentulism and its removable partial denture designs. The data was collected from the dental laboratory of each three dental colleges in Seoul and from two dental laboratories only for removable partial dentures as a prescription form. A total of 1411 cases with prescription form collected from dental laboratories were distributed for this study, then 788 cases were selected for this study. The case selection was done according to the contents of prescription form. The selected cases were divided into maxillary arch and mandibular and classified in terms of types of major connector and direct retainer, unbroken anterior teeth, Kennedy classification, the number of remaining teeth, and distribution of age and sex. The analyzed results were as follows : 1. The Kennedy classification I showed highest frequency both in maxilla and mandible. 2. The arch distribution of removable partial denture was 50.08% for maxilla and 49.92% for mandible. 3. The highest frequency in the distribution of direct retainer was the RPA clasp design. 4. The frequency of unbroken anterior 6 was 73.36% for maxilla and 82.30% for mandible. 5. The design of broad palatal strap and lingual bar revealed the highest prevalence in the major connector construction. 6. The mean number of remaining teeth per arch was 8.25 for maxilla and 8.37 for mandible. 7. The mean age of the patients supplied with removable partial denture was 52.25 years for men, 51.68 years for women, 52.11 years for maxilla, and 51.76 years for mandible and women showed more prevalence.

• Journal of Korean Dental Science
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• v.15 no.1
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• pp.61-67
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• 2022

Purpose: This study aimed to evaluate the accuracy of bite registration using intraoral scanner based on data trimming strategy for fremitus teeth. Materials and Methods: A reference model was designed by Medit Model Builder software (MEDIT Corp., Seoul). Tooth number 24 and 25 were separated as dies and tooth number 26 was prepared for full-coverage crown. Those were printed using a 3D printer (NextDent 5100). The scanning procedure was performed by a single trained operator with one intraoral scanner (i700; MEDIT Corp.). The scanning groups were divided as follows: group 1 (G1), no fremitus; group 2 (G2), 0.5 mm buccal fremitus in the maxillary left first and second premolar; and group 3 (G3), 1.5 mm buccal fremitus in the maxillary left first and second premolar. Each group was scanned 10 times and were analyzed using the reference model data. Surface-based occlusal clearance was analyzed at the prepared tooth to evaluate accuracy. Result: Mean values of control group (G1) were 1.587±0.021 mm. G2 showed similar values to those from the control group (1.580±0.024 mm before trimming strategy and 1.588±0.052 mm after trimming strategy). G3 showed significantly greater values (1.627±0.025 mm before trimming strategy and 1.590±0.024 mm after trimming strategy) and the differences were found between trimming strategy (P=0.004). Conclusion: Bite trimming strategy for fremitus teeth is a reliable technique to reduce inaccuracies caused by the mobility at maximum intercuspation.

• Journal of Digital Convergence
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• v.19 no.2
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• pp.315-322
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• 2021

The purpose of this study was to examine the correlations of oral myofunction and oral environment for the elderly with systemic diseases and to suggest need to improve oral health for the elderly. Data were collected from 64 elderly over the age of 65, from April to June 2019. Data were surveyed on general characteristics, oral myofunction, oral health-related quality of life, oral bacteria. Analysis was performed using PASW Statistics ver 18.0. The subjects were 43.8% systemic diseases, among them 40.6 percent of the people with more than two. The number of functional teeth was 18.6. Age was negatively correlated with functional teeth(r=-.384, p<.01) and tongue pressure (r=-).104, p<.001). Tongue pressure was a positive correlation with lip force(r=.279, p<.05). Age and total number of bacteria was negative correlation(r=-.336, p<.01). The functional teeth and total number of bacteria was positive correlation(r=.551, p<.001). The number of systemic diseases and total number of bacteria was positive correlation(r=.327, p<.01) the analysis of oral myofunction and oral bacteria in older patients with systemic diseases It was meaningful in suggesting a plan to improve oral health for the elderly. A practical policy plan was required to improve the quality of oral health life in a super-aged society.

• Research in Community and Public Health Nursing
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• v.20 no.1
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• pp.12-22
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• 2009

Purpose: This study was done to investigate factors associated with depression and quality of life (QoL) among the community-dwelling elderly. Methods: This study used a descriptive correlational research design. The subjects were 730 elders aged over 65 living in D district of Daegu. Data were collected using questionnaires for 30 days in April, 2007. The research instruments utilized in this study were a physical function scale of long-term care insurance system, Geriatric Depression Scale Short Form Korea Version (GDSSF-K), and Korean Quality of Life Scale (KoQoLs). The collected data were analyzed by descriptive statistics, t-test, ANOVA, Duncan, stepwise multiple regression, and Spearman correlation. Results: The mean age of the subjects was 72.6, and 68.8% and 57.9% of subjects were, respectively, female and living alone. 12.3% of variance in depression was explained by age, education, economic status, subjective health, alcohol consumption, condition of teeth, and fall experience. 18.2% of variance in QoL was explained by economic status, number of diseases, condition of teeth, incontinence, paralysis, and IADL. Economic status and condition of teeth were contributing factors to depression and QoL of the elderly. Conclusion: Findings of this study may be useful in understanding the health status of the community-dwelling elderly and developing more regionally specific health promotion strategies.

• Journal of Oral Medicine and Pain
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• v.31 no.2
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• pp.121-126
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• 2006

Hypohidrotic ectodermal dysplasia refers to a group of disorders with the following common features : thin, sparse or absent hair, missing or peg-shaped teeth and inability to sweat adequately. Both the primary and secondary dentition are affected. Teeth may be absent (anodontia) or reduced in number (oligodontia) and abnormally shaped. In case, A 5-year-old man presented with hypohidrosis and dry skin. He had no teeth in mouth. We report a case of hypohidrotic ectodermal dysplasia with anodontia.

• Conservation Science in Museum
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• v.16
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• pp.114-121
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• 2015

Two pieces of comb-shaped jewelry which are made of animal bones were discovered in Daeseong-dong tomb No.88 in Gimhae. Foreign material was removed from the surface of the objects using ethanol and various small instruments. Fractures or cracks were repaired using cellulose-type synthetic resin and epoxy resin. Acrylic paint was applied repaired areas to match the color and finished conservation treatment. The two comb-shaped accessories, although differing in number of teeth and thickness, were produced by using the same method. A series of fine bone pieces, shaped like comb teeth, are placed between two long bones, assuming animal ulnas, and are fastened together by tying silk thread around them several times, then by placing a coat of lacquer.

• Tribology and Lubricants
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• v.35 no.4
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• pp.215-221
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• 2019

A gerotor set consists of two elements, an inner rotor and an outer rotor. The outer rotor has one more tooth than the inner rotor and has its centerline positioned at a fixed eccentricity from the centerline of the inner rotor. Although gerotors come in a variety of geometric configurations, all gerotor sets share the basic principle of having generated tooth profiles that provide continuous tight sealing during operation. The size of the gerotor is proportional to the number of teeth and the amount of eccentricity. The interior of an inner rotor with a large number of teeth has an enough space to include other machine elements. In this paper, the double gerotor mechanism, constructed by putting a small gerotor in the interior of a large inner rotor, is conceptualized. The double gerotor set is composed of an inner rotor, a planetary rotor, and an outer rotor. The inside profile of the planetary rotor corresponds to the outer rotor profile of the small gerotor, and the outside profile is the inner rotor profile of the large gerotor. In the double gerotor, the centers of the inner and the outer rotor are coincident because the eccentricities of two gerotors are balanced. The operation of a double gerotor is examined by analyzing the planetary motion, and a feasibility study for application of the double gerotor for hydraulic motors and pumps is performed. The double gerotor set has much application potential as a component of hydraulic systems.

• Journal of Korean society of Dental Hygiene
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• v.13 no.5
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• pp.881-888
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• 2013

Objectives : The purpose of the study is to investigate the risk factors of dental caries in early childhood. Methods : Subjects were 197 mothers having 5 year old children. They completed the questionnaire from June 1 to July 14, 2012. Results : At birth, the age of mother and the number of teeth experiencing dental caries showed high correlation(r=0.163, p<0.05). Early beginning(r=-0.441, p<0.05) and long period(r=0.441, p<0.05) of mix feeding were closely related to dental caries outbreak. Long period of supplementary food caused deciduous dental caries (r=0.643, p<0.001) and dental caries experience (r=0.723, p<0.001). Long period of breast feeding (r=0.261, p<0.001) also caused deciduous dental caries. Low BMI of mother was colsely related to high dental caries(r=-0.206, p<0.01). Deciduous dental caries accounted for 61.8% and the number of teeth experiencing dental caries was 68.5%. Conclusions : Appropriate breast feeding habit is the most important behavior of preventing deciduous dental caries in 5 year old children.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.3
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• pp.135-141
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• 2023

Objectives: This study aimed to develop and validate machine learning (ML) models using H₂O-AutoML, an automated ML program, for predicting medication-related osteonecrosis of the jaw (MRONJ) in patients with osteoporosis undergoing tooth extraction or implantation. Patients and Methods: We conducted a retrospective chart review of 340 patients who visited Dankook University Dental Hospital between January 2019 and June 2022 who met the following inclusion criteria: female, age ≥55 years, osteoporosis treated with antiresorptive therapy, and recent dental extraction or implantation. We considered medication administration and duration, demographics, and systemic factors (age and medical history). Local factors, such as surgical method, number of operated teeth, and operation area, were also included. Six algorithms were used to generate the MRONJ prediction model. Results: Gradient boosting demonstrated the best diagnostic accuracy, with an area under the receiver operating characteristic curve (AUC) of 0.8283. Validation with the test dataset yielded a stable AUC of 0.7526. Variable importance analysis identified duration of medication as the most important variable, followed by age, number of teeth operated, and operation site. Conclusion: ML models can help predict MRONJ occurrence in patients with osteoporosis undergoing tooth extraction or implantation based on questionnaire data acquired at the first visit.

• Journal of Periodontal and Implant Science
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• v.23 no.3
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• pp.442-453
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• 1993

In order to determine the relationship between probing pocket depth and trypsin-like activity in subgingival plaque, probing pocket depth and loss of attachment were measured by Michigan-O probe on mandibular incisors of 30 patients with adult periodontitis. And the trypsin-like activity of Treponema denticola, Porphyromonas gingivalis, and Bacteroides forsythus was evaluated by the hydrolysis of N-Benzoyl-DL-Arginine-2-Naphthyla-mide (BANA) using PerioScan reagent cards(Oral-B Laboratories, Redwood City, CA). The obtained data were statistically analyzed by Microstat program. The results were as follows. 1. The number of teeth showing negative trypsin-like activity was more in shallow periodontal pocket groups, but the number of teeth showing positive trypsin-like activity was more in deep periodontal pocket groups. 2. There was a significant positive correlation between probing pocket depth and trypsin-like activity in subgingival plaque(y=0.413X - 0.955, r = 0.7024, p<0.001). 3. There was no consistent relationship between loss of attachment and trypsin-like activity in subgingival plaque(p>0.01).