• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.51-61
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• 2001

Cleft lip and/or palate (CLP) is one of the most common congenital craniofacial anomalies and occurs more frequently in Asian people. Dental abnormalities in number, size, shape, and eruption of teeth are frequently associated with CLP. The purposes of this study were to investigate the effects of CLP on number, size, shape and eruption of teeth and to provide basic clinical data for diagnosis and treatment of the CLP patients. With the orthodontic and cleft charts, diagnostic models, orthopantomograms and intraoral x-ray films from 241 CLP patients who visited Dept. of Orthodontics, Seoul National University Dental Hospital, we evaluated the frequency of congenital missing teeth, supernumerary teeth, Impacted teeth, and microdontia. The results were as fellows ; 1. Frequency of congenital missing was relatively high up to $56.8\%$. Congenital missing occurred frequently in the maxillary lateral incisor and the maxillary second premolar. Among the CLP types, frequencies of congenital missing in cleft lip and Palate group and cleft lip and alveolus group were higher than those of cleft lip group and cleft palate group. And bilateral cleft showed higher frequencies than unilateral ones. 2. Supernumerary tooth was shown in $11.2\%$ of CLP patients. It occurred frequently in the area between the maxillary lateral Incisors and the maxillary canine. Among the CLP types, cleft lip group showed relatively most highest frequency. 3. Impaction was shown in $18.3\%$ of CLP patients. It occurred most frequently In the maxillary lateral incisor and the maxillary canine than other teeth. Among the CLP types, cleft lip group and cleft lip and palate group showed most highest frequencies. 4. Microdontia was shown in $15.8\%$ of CLP patients. It occurred the most frequently In the maxillary lateral incisors and maxillary canines. Among the CLP types, cleft lip and alveolus group and cleft lip and palate group showed relatively higher frequencies. There was no microdontia in cleft palate group.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.25-34
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• 2022

This study aimed to investigate a quantitative analysis of the anatomical characteristics of the maxillary supernumerary lateral incisor and its relationship with lateral incisors. Forty-four supernumerary lateral incisors from 43 patients were evaluated for analyzing the position, shape, direction, and relationship between the supernumerary lateral incisor and the normal lateral incisors, using cone-beam computed tomography (CBCT). To compare the size of crown, the mesio-distal width was measured and the Nolla stage was used for evaluating the degree of root development to compare tooth maturity. The supernumerary lateral incisors were in the normal direction at a rate of 90.9%, and in a supplemental shape at a rate of 84.1%. The supernumerary lateral incisor was smaller in size compared to the adjacent lateral incisor and opposite lateral incisor (p < .0001). There was no statistically significant difference in the development stage of root. Based on these results, the supernumerary lateral incisor is similar with the lateral incisor, but has a difference in the size of crown. It is necessary to distinguish the supernumerary lateral incisor from the lateral incisor precisely to reduce clinical complications.

• Journal of dental hygiene science
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• v.22 no.1
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• pp.57-66
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• 2022

Background: This study aimed to investigate the effect of selecting commercially available blending teas and applying them to bovine teeth on color change over time. Methods: After selecting healthy bovine teeth, using a cutting-disc, 105 specimens with a dimension of 5×5×3 mm were prepared, and 15 specimens were distributed to each group. Black tea was used as a positive control, water was used as a negative control, and blended tea of five types was used as an experimental group. First, pH and buffering capacity were measured with a pH meter, and tooth color was determined using a spectrophotometer before immersion in the blending tea solution and 1, 5, 7, 14, and 21 days after immersion. Thereafter, the shape change of the enamel surface was observed using a scanning electron microscope, and SPSS ver.26 was used to analyze the color change. Results: The average pH of the five blending teas in the experimental group was 3.78, and the pH of group 3 (strawberry rhubarb) was the lowest at 3.22. The pH levels of black tea and water were 5.19 and 7.30, respectively. The buffering capacity was the highest in group 3 at both pH levels of 5.5 and 7.0. The L^*a^*b^* color change according to immersion time was the largest in group 4 (rooibos yellow flower), and the amount of color change was large in black tea and group 4. As a result of observing the enamel surface of bovine teeth, changes in the surface shape were noted in all groups immersed in the experimental solution for 21 days, except for water. Conclusion: There was a significant difference between the experimental groups in terms of color change according to the immersion time, and color and enamel surface changes were observed in black tea and all experimental groups, except for water.

• Journal of Dental Rehabilitation and Applied Science
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• v.40 no.2
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• pp.82-90
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• 2024

It often happens that a removable partial denture needs to be repaired due to tissue changes in the remaining alveolar ridge, fracture of the denture, or fracture of the abutment tooth. There are several advantages to retrofitting a customized surveyed crown under the existing RPD. Retrofitting a crown to the RPD decreases the economic burden to the patient and avoids the need for several appointments to fabricate a new RPD. It is difficult for artificial teeth used to repair dentures due to fractured natural teeth to have a shape similar to that of natural teeth, and to repair aesthetic artificial teeth, it is necessary to manufacture customized artificial teeth similar to the shape of each patient's teeth. Recently, CAD/CAM technology has been used to fabricate customized prosthetics on existing RPD to achieve high retention and fitness accuracy, and by manufacturing customized artificial teeth, more aesthetic and harmonious artificial tooth repair is possible. This is a case in which a denture was repaired using a digital method to fabricate a customized prosthesis on an existing partial denture and customized artificial teeth that mirrored the adjacent dentition, saving time and cost, simplifying the process, and achieving aesthetically and functionally satisfactory results.

• Journal of dental hygiene science
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• v.11 no.2
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• pp.121-127
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• 2011

This study was conducted to improve patients satisfaction by comparing patients expectation prior to the implant therapy to patient satisfaction after the implant therapy. The data of 158 patients with dental implant in Seoul, Gyeonggi-Do and Cheonan city was obtained. The results are as follows : 1. 40.5% of patients placed one implant and 36.1 % of patients answered that the average cost for each implant is from 1,500,000 to 2,000,000won. 23.4% of them answered they decided to have implant because no tooth preparation is required. 2. Overall, the expectation level for implant therapy in general properties, women showed higher level of expectation than men. Especially, 'Implant has a longer life than other denture' showed significant difference between women(4.29) and men(3.87). Expectation by age, 'Implant has similar color and shape' was found the highest in age 20(4.38). Satisfaction by general properties, 'No tooth preparation required' was found the highest in age 20(4.57) and was statistically significant(p<.002). 3. Comparing patients' expectation prior to implant therapy to satisfaction afterward, 'Implant prevents jawbone resorption and keeps facial appearance' showed 3.7 of expectation but satisfaction was found increased to 3.87(p=.020). No tooth preparation required' was found 3.95 in expectation prior to implant therapy but after therapy it was found 4.23 in satisfaction (p<.001). 4. Overall satisfaction in implant therapy was found 4.25, recommendation to other patients was found 4.18 and repurchase was found 4.17.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.5
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• pp.567-578
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• 2007

Statement of problem: The endodontically treated tooth is generally restored with post and core, owing to the brittle and the loss of large amount of tooth structure. As periodontal treatment was developed, there are many cases that periodontally involved teeth used in prosthetic treatment. Purpose: The purpose of this study was to analyze the stress distribution in the dentin and post structures by the various post materials and the amount of remaining alveolar bone height. Material and method: The 3-dimensional finite element models of mandible 1st premolars were divided into six types according to the various amount of remaining alveolar bone and post type. All types were modeled using equal length, diameter and shape of the post. Three types of post and core materials were used: prefabricated titaniumpost and amalgam core, prefabricated stainless steel post and amalgam core, and cast gold post and core. 300 Newton force was applied to functional cusp of mandible 1st premolar. Results: The results were as follows: First, there was no apparent difference in the pattern of stress distribution according to the alveolar bone condition concentrate on the post middle area. Second, there was difference in pattern of stress distribution according to the core materials, gold post and core generated same than amalgam core. Third, there was no apparent difference in the pattern of stress distribution within the dentin according to the post and core materials. But a cast gold post and core generated the lowest maximum stress value, a stainless steel post generated the highest maximum stress value. Fourth, in the reduced alveolar bone model, maximum stress value is 1.5 times than that of the normal alveolar bone model. Conclusion: Within the limitations of this study, to provide minimal stress to the root with alveolar bone reduced, the post length may be as long as apical seal was not destroyed. To prevent fracture of tooth, it is rational to use gold alloy which material was good for stress distribution for post materials.

• Korean Journal of Plant Taxonomy
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• v.42 no.2
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• pp.150-156
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• 2012

While preparing a floristic study of Korean hepatics, we discovered the six unrecorded species of Lejeuneaceae from Mt. Seolak, Mt. Gaya, Geojedo, Wando and Gageodo. Archilejeunea kiushiana, Drepanolejeunea angustifolia, Lejeunea aquatica, Lejeunea otiana, Leucolejeunea japonica, and Spruceanthus semirepandus, are reported here. A. kiushiana was characterized by unlobed underleaves, homogeneous oil-bodies, and four to six perianth-keels. D. angustifolia is similar to D. ternatensis, but it differs in the dorsal margin of the leaf-lobe, which is entire or denticulate, spines never present, and leaf cells smooth or with minute dorsal bulging. L. aquatica is similar to L. japonica in that it has a wider and similar shape (wider than long) of its underleaves and has homogeneous oil-bodies. The former, however, has minute leaf-lobules (5-15 cells), 1/10 to 1/5 the length of the leaf-lobe, versus leaf-lobules 1/4 to 1/3 the length of the leaf-lobe. L. otiana is similar to L. kodamae in that it has a large and acute first tooth of the leaf-lobule but differs in having plain leaf-lobules obliquely quadrate and an indistinct second tooth. Drepanolejeunea (Spruce) Schiffn. is widely distributed in tropical and subtropical regions (Mizutani, 1961). L. japonica is characterized by entire underleaves; one large, coarsely segmented oil-body per leaf cell; and a large second tooth of the leaf lobule, two to six cells long, and two to three cells wide at the base. S. semirepandus is widely distributed in tropical and subtropical regions in Asia. This species is characterized by small homogeneous and numerous oil-bodies, up to 10 smooth perianthkeels, and leaf-lobe acute at the apex.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4354-4359
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• 2010

The study performed questionnaire to the patients receiving implant operation, who visited dental clinics and hospitals(2 hospitals and 5 clinics) from Jul. 1, 2009 to Sep. 12, 2009 in order to study the factors giving effects to patient's satisfaction in the selection of implant. 145 questionnaire papers collected from patients were analyzed with SPSS12.0 program. The result revealed that the satisfaction with implant operation was usually normal when implant was operated because of tooth extraction due to dental caries and periodontal disease and it was usually high when implant was operated because of wound(P<0.05). When considering each cause of tooth extraction, the satisfaction with pronunciation function was usually normal(P<0.001), the satisfaction with functional part including foreign body sense was very low when the cause of operation was periodontal disease(P<0.01). The satisfaction with hospital environment depending on the cause of hospital selection was usually high when hospital was selected because of doctor's fame. It was low when hospital was selected because it was close to home(P<0.001). The satisfaction with the number of hospital visits depending on the number of implanted teeth was usually low when many teeth were implanted(P<0.01). The analysis on the satisfaction with tooth shape and color showed that the satisfaction was high when '1~2' teeth and 'more than 6' teeth were implanted(P<0.05). In order to improve patient's satisfaction with implant, it is necessary to recognize individual's oral status and request correctly. It is determined that proposal of operation period, number of hospital visits, function and expected aesthetic satisfaction degree will contribute to the improvement of mutual reliance between doctor and patient and post-operation satisfaction degree.

• The Journal of Korean Academy of Prosthodontics
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• v.57 no.4
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• pp.397-404
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• 2019

Bone and soft tissue conditions are important for successful implant treatment. But, the placement itself is also very important. Implants which is installed in the wrong position result in the biological, esthetical and mechanical problems. In order to place an implant in the correct position, the final restoration and diagnostic wax-up should be considered prior to the surgery. If the artificial teeth for the interim denture are directly transferred from the diagnostic wax-up, the operator can try the form of diagnostic wax-up in the mouth. If the surgical template is produced by duplicating the interim denture, the implant can be placed in the planned position. In this case, the polymethyl methacrylate (PMMA) artificial tooth was precisely milled by the digital duplication of diagnostic wax-up. And interim denture was fabricated by using these milled teeth. After the patient adapted for a sufficient period, the implant was placed at the planned position with surgical template produced by duplicating the interim denture. After confirming sufficient osseointegration, the final prostheses were made to reflect the shape of diagnostic wax-up. Through this procedure, the satisfactory functional and esthetic outcome could be acquired.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.145-152
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• 2012

Whenever pediatric dentists choose the preformed stainless steel crowns for restoration of primary molars, we usually prefer the crown forms that most fit to the abutment teeth. Despite some previous reports on significant ethnic difference in the size and shape of tooth crowns in primary dentition, only the imported products have been available to date, which might show some discrepancy with tooth anatomy of Korean. However, a domestic product of preformed stainless steel crown has been marketed recently that is expected to show more accurate fit to the primary tooth of Korean. To investigate the morphological characteristics of primary molars of Korean children, their mesiodistal and buccolingual diameters from the dental casts of 263 children in Pusan and Kyungsangnamdo province were measured by digital calipers. The measured data were compared with those of the three types of preformed stainless steel crowns(3M ESPE Stainless Steel Primary Molar Crown, Kids Crown, Sankin Anatom Primary Crown) by statistical processes with regression analysis. The results were as follows: 1. In every primary molar crown of three brands, the bucco-lingual width to mesio-distal width ratio (MD-BL ratio) showed higher values compared with those of natural teeth. 2. While the products of 3M ESPE and Shinhung showed similar features, those of Sankin showed some difference from both, and these difference was more marked in mandibular primary molars. 3. The nearer is the mesio-distal width of the crown to the average, the better was the adaptation of the preformed crown, and the reverse was true. 4. The teeth which revealed more discrepancy between preformed crown and natural tooth were upper and lower first primary molars.