1.A morphometric analysis of maxillary central incisor on the basis of facial appearance in Korea.
Ji Eun KU ; Hong So YANG ; Kwi Dug YUN
The Journal of Advanced Prosthodontics 2012;4(1):13-17
PURPOSE: We aimed to identify a more esthetic width-to-length ratio by analyzing maxillary central incisor of Korean adult population. Information regarding tooth ratio in the Korean population may be useful to clinicians when restoring anterior teeth. MATERIALS AND METHODS: A total of 40 men and 40 women were included in this study. The NON-MEDIA group included 40 non-celebrities, who were healthy and 25 to 39 years old, with normal dentofacial appearance. The MEDIA group consisted of 40 celebrities selected only on the basis of their soft-tissue facial appearance. The facial photographs of 40 celebrities were collected from the Internet websites. The width and length of the maxillary central incisor were measured using Adobe Photoshop(R) 7.0, a software for analysis, measurement and edition of photographs. Data were analyzed statistically using the Independent t-test at 5% statistical significance level. RESULTS: The mean ratio for the MEDIA group was 0.77, whereas that of the NON-MEDIA group was 0.88. The difference between the two groups was statistically significant. No significant gender differences were found in the width-to-length ratio in MEDIA group. In NON-MEDIA group, however, there were significant differences between female and male. CONCLUSION: After analyzing maxillary anterior teeth of Korean adults, our results were in accordance with the general Western standards of esthetics. A dentist restoring the natural look and beauty of teeth will have to consider those standards.
Adult
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Anodontia
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Beauty
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Dentists
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Esthetics
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Female
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Humans
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Incisor
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Internet
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Korea
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Male
;
Tooth
2.A morphometric analysis of maxillary central incisor on the basis of facial appearance in Korea.
Ji Eun KU ; Hong So YANG ; Kwi Dug YUN
The Journal of Advanced Prosthodontics 2012;4(1):13-17
PURPOSE: We aimed to identify a more esthetic width-to-length ratio by analyzing maxillary central incisor of Korean adult population. Information regarding tooth ratio in the Korean population may be useful to clinicians when restoring anterior teeth. MATERIALS AND METHODS: A total of 40 men and 40 women were included in this study. The NON-MEDIA group included 40 non-celebrities, who were healthy and 25 to 39 years old, with normal dentofacial appearance. The MEDIA group consisted of 40 celebrities selected only on the basis of their soft-tissue facial appearance. The facial photographs of 40 celebrities were collected from the Internet websites. The width and length of the maxillary central incisor were measured using Adobe Photoshop(R) 7.0, a software for analysis, measurement and edition of photographs. Data were analyzed statistically using the Independent t-test at 5% statistical significance level. RESULTS: The mean ratio for the MEDIA group was 0.77, whereas that of the NON-MEDIA group was 0.88. The difference between the two groups was statistically significant. No significant gender differences were found in the width-to-length ratio in MEDIA group. In NON-MEDIA group, however, there were significant differences between female and male. CONCLUSION: After analyzing maxillary anterior teeth of Korean adults, our results were in accordance with the general Western standards of esthetics. A dentist restoring the natural look and beauty of teeth will have to consider those standards.
Adult
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Anodontia
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Beauty
;
Dentists
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Esthetics
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Female
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Humans
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Incisor
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Internet
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Korea
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Male
;
Tooth
3.Comparative evaluation using cephalometric radiographs in patients with full mouth rehabilitation by changing the vertical dimension
Juyoung PARK ; Sangwon PARK ; Kwi-Dug YUN ; Woohyung JANG
International Journal of Oral Biology 2021;46(4):208-213
Increasing the vertical dimesion affects not only functional problems but also the facial appearance. In particular, when restoring the reduced vertical dimension, it is important to evaluate facial appearance because the change affects the patient’s aesthetics. Cephalometric radiographs can predict changes in the facial appearance through skeletal and vertical classifications using anatomical indicators, and the changes before and after treatment can be easily observed, which could serve as good data in evaluating treatment success. In this study, comparative evaluation was performed through cephalometric radiography, and the aesthetic and functional improvement was confirmed.
4.Antimicrobial activity of dental polishing bur material with fluoride ion
Insun JEONG ; Ji-Hyun KIM ; Kwi-Dug YUN
The Journal of Korean Academy of Prosthodontics 2020;58(3):201-206
Purpose:
The purpose of this study is to evaluate the antimicrobial activity on the dental bur with fluoride for S. mutans.
Materials and methods:
0 ppm, 300 ppm, 500 ppm, 1,000 ppm, 1,450 ppm fluoride ion is added to a specimen. S. mutans was incubated for 24 hours, the number of S. mutans were counted. Kruskal-Wallis and Mann- Whitney analysis were used SPSS 25.0 (IBM SPSS 25.0, Chicago, IL, USA).
Results:
The mean S. mutans counts of 0 ppm, 300 ppm, 500 ppm, 1,000 ppm, and 1,450 ppm were 374.0 ± 12.6, 251.0 ± 66.7, 111.4 ± 35.6, 41.6 ± 11.7 and 13.2 ± 4.6, respectively. All groups except the control and 300 ppm showed statistically significant.
Conclusion
Thus, more than 500 ppm fluoride ion showed the statistically significant antimicrobial activity. 1,450 ppm group showed the highest antimicrobial activity. This study showed the clinical possibility for dental caries protection and antimicrobial activity of dental bur.
5.Adaptability of zirconia core fabricated by cold isostatic pressing.
Yoon Jeong SEO ; Kwi Dug YUN ; Hyun Seung KIM ; Sang Won PARK
The Journal of Korean Academy of Prosthodontics 2010;48(2):143-150
PURPOSE: The purpose of this study is to fabricate the new zirconia block (CNU block) and to evaluate fit of core and porcelain veneered zirconia crown. MATERIAL AND METHODS: The experimental blocks were fabricated from the commercial ytrria-stabilized zirconia powder (KZ-3YE Type A). The powder was uniaxial pressing and the green bodies were conducted using the Cold Isostatic Pressing. The zirconia blocks were presintered at 1040degrees C and the final sintering was performed at 1450degrees C. The Kavo Everest ZS blank(R) (KaVo, Biberach/Ri beta.) was used as a control group. The linear shrinkage of CNU block and Kavo block were compared. Twenty-one cores for porcelain veneered crowns were fabricated with CAD/CAM system (Everest(R), Biberach/Ribeta.). Group I: seven cores fabricated from Kavo blocks, Group II: seven cores fabricated from CNU blocks, Group III: seven cores from CNU blocks and porcelain veneering for crowns. All specimens were cemented and sectioned into two planes: diagonal and bucco-lingual. The measurement of the marginal, internal, and occlusal fit was carried out using SEM (S-4800(R)) at 30 x. The results were analyzed by one-way ANOVA test. RESULTS: The linear shrinkage of the CNU block and the KaVo block was 19.00% and 20.09%. The marginal gap of cores (29.67 +/- 6.58 micrometer) fabricated from CNU blocks showed significantly smaller than that of the cores of Kavo blocks (36.84 +/- 7.18 micrometer) (P < .05). The internal gaps of the porcelain veneered crowns (32.23 +/- 6.33 micrometer) were larger than those of the other two groups (37.57 +/- 6.81 micrometer and 38.14 +/- 6.81 micrometer). CONCLUSION: No statistically significant difference was found in between experimental groups and control group. The experimental groups in marginal gap showed significantly smaller than the control group.
Cold Temperature
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Crowns
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Dental Porcelain
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Ethylnitrosourea
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Zirconium
6.Implant restoration considering maintenance for a patient with excessive crown height space.
Juri MA ; Hong So YANG ; Sang Won PARK ; Hyun Pil LIM ; Kwi Dug YUN ; Mong Sook VANG
The Journal of Korean Academy of Prosthodontics 2013;51(2):107-112
Complications increases when crown height space is excessive and one should be careful of choosing type of fixed prosthesis in case crown height space is over 12 mm. In this condition, tooth seems to be longer, therefore, it is needed to use gingival shade in aesthetically important area for fixed prosthesis. In this case, fixed prosthesis which has inappropriate maintenance and hygiene could hold food, plaque, calculus, thus increase incidence of inflammation and infection. Moreover, it could lead to chronic inflammation and infection and in that case surgical improvement could be necessary. In present case report, gingival inflammation and swelling developed around prosthesis after having made it considering articulation and aesthetic view in patient who had excessive crown height space. Finding out that design of prosthesis is a factor to make it hard to maintain oral hygiene, a temporary prosthesis which has enough interproximal space and proper emergence profile was fabricated. After two months of observation, significant abnormal symptoms are not found and oral reconstruction is performed using fixed prosthesis with zircornia infrastructure and porcelain build-up based on convenient self hygiene design. Through serial treatment, inappropriate soft tissue response is not observed and satisfactory result in functional aspect comes out.
Calculi
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Crowns
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Dental Porcelain
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Humans
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Hygiene
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Incidence
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Inflammation
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Oral Hygiene
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Prostheses and Implants
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Tooth
7.Rehabilitation in a patient with limited restorable space using double scanning technique: A case report.
Jun Yub KIM ; Sang Won PARK ; Hyun Pil LIM ; Kwi Dug YUN ; Hongso YANG
The Journal of Korean Academy of Prosthodontics 2017;55(2):205-211
Loss of posterior support may cause extrusion of antagonistic teeth and excessive wear of remaining teeth which often leads to the destruction of the occlusal plane. In such cases, it is critical to verify the need to increase vertical dimension of occlusion (VDO). Should you increase VDO, provisionalization is crucial in evaluating function and esthetics. Double scanning technique is a useful method when fabricating definitive restoration that mimic provisional restoration. In this case, a patient with apparently no loss of VDO and insufficient interocclusal space for dental materials due to loss of posterior support and extrusion of antagonistic teeth was rehabilitated using double scanning technique.
Dental Materials
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Dental Occlusion
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Esthetics
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Humans
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Methods
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Rehabilitation*
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Tooth
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Vertical Dimension
8.Three-dimensional finite element analysis of stress distribution for different implant thread slope and implant angulation.
Young Hun SEO ; Hyun Pil LIM ; Kwi Dug YUN ; Suk Ja YOON ; Mong Sook VANG
The Journal of Korean Academy of Prosthodontics 2013;51(1):1-10
PURPOSE: The purpose of this study was to find an inclination slope of the screw thread that is favorable in distributing the stresses to alveolar bone by using three dimensional finite element analysis. MATERIALS AND METHODS: Three types modelling changed implant thread with fixed pitch of 0.8 mm is the single thread implant with 3.8degrees inclination, double thread implant with 7.7degrees inclination and the triple thread implant with 11.5degrees inclination. And three types implant angulation is the 0degrees, 10degrees and 15degrees on alveolar bone. The 9 modelling fabricated for three dimensional finite element analysis that restored prosthesis crown. The crown center applied on 200 N vertical load and 15degrees tilting load. RESULTS: 1. The more tilting of implant angulation, the more Von-Mises stress and Max principal stress is increasing. 2. Von-Mises stress and Max principal stress is increasing when applied 15degrees tilting load than vertical load on the bone. 3. When the number of thread increased, the amount of Von-Mises stress, Max principal stress was reduced since the generated stress was effectively distributed. 4. Since the maximum principal stress affects on the alveolar bone can influence deeply on the longevity of the implants. When comparing the magnitude of the maximum principal stress, the triple thread implant had a least amount of stress. This shows that the triple thread implant gave a best result. CONCLUSION: A triple thread implant to increase in the thread slope inclination and number of thread is more effective on the distribution of stress than the single and double thread implants especially, implant angulation is more tilting than 10degrees on alveolar bone. Thus, effective combination of thread number and thread slope inclination can help prolonging the longevity of implant.
Crowns
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Finite Element Analysis
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Longevity
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Prostheses and Implants
9.Rehabilitation using twin-stage method for a Sjögren's syndrome patient with severe discoloration and attrition on upper and lower anterior teeth.
Seon Ki LEE ; Hong So YANG ; Sang Won PARK ; Hyun Pil LIM ; Kwi Dug YUN
The Journal of Korean Academy of Prosthodontics 2016;54(3):291-297
Patients with Sjögren's syndrome usually suffer from teeth discoloration and attrition due to xerostomia. If the anterior teeth are badly worn, problems such as loss of anterior guidance, occlusal disharmony, and limited space for restoration may occur. However, ideal occlusion is obtained in both centric and eccentric relation by regaining the disocclusion of the posterior teeth through the anterior and lateral guidance using twin-stage method. In this case, rehabilitation was performed for a Sjögren's syndrome patient with maxillary and mandibular incisor's severe attrition and teeth discoloration by using twin-stage method.
Dental Occlusion
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Humans
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Methods*
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Rehabilitation*
;
Tooth*
;
Xerostomia
10.Rehabilitation using twin-stage method for a Sjögren's syndrome patient with severe discoloration and attrition on upper and lower anterior teeth.
Seon Ki LEE ; Hong So YANG ; Sang Won PARK ; Hyun Pil LIM ; Kwi Dug YUN
The Journal of Korean Academy of Prosthodontics 2016;54(3):291-297
Patients with Sjögren's syndrome usually suffer from teeth discoloration and attrition due to xerostomia. If the anterior teeth are badly worn, problems such as loss of anterior guidance, occlusal disharmony, and limited space for restoration may occur. However, ideal occlusion is obtained in both centric and eccentric relation by regaining the disocclusion of the posterior teeth through the anterior and lateral guidance using twin-stage method. In this case, rehabilitation was performed for a Sjögren's syndrome patient with maxillary and mandibular incisor's severe attrition and teeth discoloration by using twin-stage method.
Dental Occlusion
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Humans
;
Methods*
;
Rehabilitation*
;
Tooth*
;
Xerostomia