• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.4
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• pp.843-848
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• 1998

Pulpotomy is a frequently used treatment modality in primary teeth. It is method by which infected coronal pulp is removed while retaining vital radicular pulp. Since its introduction in 1930 by Sweet formocresol remains the most popular medicament for this treatment. However, despite its outstanding bactericidal properties, formocresol is known to cause adverse tissue reactions. Theoretically, formocresol disinfects and fixes radicular pulp and thus prevents infection and internal resorption. In reality, however, it leads to chronic inflammation and is sometimes responsible for failures through abscess formation and internal root resorption. Also, Myers et al., in 1978, reported on the systemic distribution of FC and other studies have followed with reports of its immunological, mutagenic and carcinogenic effects. Much effort has, therefore, focused on the development of alternative medicaments and techniques. Since its introduction in 19C, ferric sulfate proven itself as an effective hemostatic agent and is used as an astringent in dentistry. In 1988, Landau and Johnsen suggested ferric sulfate be used as a medicament in pulpotomy and many studies have focused on it to overcome the toxic effects of FC. Ferric sulfate acts through its ferric ion and iron ion, which react with blood protein leading to aggregation. The aggregated protein acts to plug the blood vessels, causing mechanical hemostasis. As blood clot formation is minimal, there is reduced inflammation of radicular pulp and enhanced healing. There are no reports regarding its systemic distribution. This is a report of cases treated by the author using pulpotomy with ferric sulfate.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.1
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• pp.41-45
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• 2004

In the normal growth and development of the mandible, the molar tooth buds distal to the first permanent molar have a mesial inclination. This inclination is usually self-correcting, but, unfortunately, this self-correction does not always occur. The first case is about, 14-year-old female patient with familial history of lower second molar impaction. Her lower second molars were both impacted, and she was treated with sectional wires and open-coil springs. The second case, 14-year-old male, we treated his impacted #47 with Halterman appliance. The third case, 11-year-old male, his both mandibular second molars were impacted during full-fixed orthodontic treatment. They were treated with brass wire, sectional wire and open-coil spring.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.1
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• pp.64-71
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• 2014

Mesiodens is defined as a supernumerary tooth in the premaxillary region. It can cause several clinical manifestations in normal eruption and position of adjacent teeth, such as displacement and impaction. Although the mesiodens accompanied by a clinical complication is indicated for removal, the optimal time of mesiodens removal is still controversial. Some authors suggest immediate intervention defining the removal of mesiodens as soon as possible after the first detection. On the other hand, others recommend delayed intervention which denotes the removal of mesiodens after complete root development of adjacent teeth. This case report is presented with three cases of spontaneous correction and proper alignment of rotated maxillary central incisors by extraction of mesiodens when the crowns of rotated incisors were completely formed while the roots of them were at an early developmental stage.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.6 no.1
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• pp.19-22
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• 2010

Cerebral palsy is an umbrella term encompassing a group of non-progressive non-contagious motor conditions that cause physical disability in human development. Motor disorder of cerebral palsy is often accompanied by disturbances of sensation, perception, cognition, communication, behavior and seizure disorder. Disharmony of motor function leads to frequent falling down. Moreover patients have high prevalence of class II malocclusion. Compared to normal patients, the patients with cerebral palsy tends to have high prevalence of recurrent trauma and bruxism which make restoration of the anterior tooth more difficult. This case report is consisted of three cases of cerebral palsy patients who have challenging problems with restoration of anterior teeth.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.25 no.2
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• pp.88-97
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• 2016

Aesthetics can be affected by the interest and the trend of the time. There are the limits of the equipment and materials required for the times, aesthetic case is also considered necessary to overcome them and will introduce the following case in accordance with the patients demands and circumstances. I hope the further development of CAD/CAM by taking over the things have done in the analogue by utilizing the latest technology that is thought to challenge the current limit itself is important. Digital has the advantages in various perspectives. Especially, I am very interested in as related to "digital communication." In particular, when utilizing the data using intra oral scanner can easily direct converse about prosthesis between the dentist and the dental technician through a software program Now, as the digital communication affects the integrity of the prosthesis directly, I had a expectation of a new era for the prosthetic and aesthetics. In this case report, I would like to introduce direct and real digital communication through the following 2 parts.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.36 no.1
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• pp.7-15
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• 2010

Complex human tissues harbor stem cells and precursor cells, which are responsible for tissue development or repair. Recently, dental tissues such as dental pulp, periodontal ligament (PDL), dental follicle have been identified as easily accessible sources of undifferentiated cells. These tissues contain mesenchymal stem cells that can be differentiate into bone, cartilage, fat or muscle by exposing them to specific growth conditions. In this study, the authors procured the stem cell from pulp, PDL, and dental follicle and differentiate them into osteoblast and examine the bone induction capacity. Dental pulp stem cell (DPSC), periodontal ligament stem cell (PDLSC), and dental follicle precursor cell (DFPC) were obtained from human 3rd molar and cultured. Each cell was analyzed for presence of stem cell by fluorescence activated cell sorter (FACs) against CD44, CD105 and CD34, CD45. Each stem cell was cultured, expanded and grown in an osteogenic culture medium to allow formation of a layer of extracellular bone matrix. Osteogenic pathway was checked by alizarin red staining, alkaline phosphatase (ALP) activity test and RT-PCR for ALP and osteocalcin (OCN) gene expression. According to results from FACs, mesenchymal stem cell existed in pulp, PDL, and dental follicle. As culturing with bone differentiation medium, stem cells were differentiated to osteoblast like cell. Compare with stem cell from pulp, PDL and dental follicle-originated stem cell has more osteogenic effect and it was assumed that the character of donor cell was able to affect on differential potency of stem cell. From this article, we are able to verify the pulp, PDL, and dental follicle from extracted tooth, and these can be a source of osteoblast and stem cell for tissue engineering.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.10
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• pp.57-64
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• 2004

The objective of this study is to suggest the form rolling technology to produce high precision worm on the base of three dimensional finite element simulation and experiment. It is important to determine the initial workpiece diameter in form rolling because it affects the quality of tooth profile. The calculation method of the initial workpiece diameter in form rolling is suggested and it is verified by finite element simulation. The form rolling processes of worm shaft used as automotive part using both the rack dies of counter flow type and the roll dies are considered and simulated with the same numerical model as actual process by the commercial finite element code, BEFORM-3D. Deformation modes of workpiece between the form rolling by the rack dies of counter flow type and the roll dies are investigated from the result of simulation. The experiments using rack dies and roll dies are performed under the same conditions as those of simulation. The surface roughness, the straightness and the profile of worm are measured precisely using the worm shafts obtained from experiment. The results of simulation and experiment in this study show that the form rolling process of worn shaft using the rack dies is decidedly superior to that using roll dies from the aspect of the precision of worm such as the surface roughness, the straightness and the profile of worm.

• Korean Journal of Plant Taxonomy
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• v.32 no.4
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• pp.397-416
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• 2002

A taxonomic study of Viola section Chamaemelanium in Korea, based on morphological characters, was conducted with light microscopy and scanning electron microscopy. Two species, V. orientalis W. Becker and V. brevistipulata (Fr. et Sav.) W. Becker, are recognized by rhizome and cauline habits, trichomes on the ovary and the shape and beards of stigmas. The latter can be split further into three varieties, var. brevistipulata, var. minor Nakai and var. laciniata (Boiss.) W. Becker, according to the leaf morphology in particular. Viola brevistipulata var. laciniata has the most tooth number, and its teeth are irregular erose but the other two varieties are regular sinuate or serrate. As for the size of leaves, V. brevistipular var. brevistipulata is the largest but V. brevistipulata var. minor is the smallest among the varities. Of them, V. brevistipulata var. laciniata is newly recorded in Korea. It was also revealed that both development and arrangement of the beards developed on the ovary and stigma were particularly diagnostic in the identification of the Viola section Chamaemelanium species.

• Journal of Korean society of Dental Hygiene
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• v.7 no.1
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• pp.1-13
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• 2007

In Korea, respect for the aged and filial devotion is treated as basic ethics for human life, and family takes care of the aged person mainly. Nowadays, family support on the aged person is prioritized than the others. However, number of aged person is growing, and family, which is used to protect the aged, becomes nuclear through industrialization. In addition, social advancement of female induces weakened supporting function of family, and all these issues generate the problem of protection for the aged as significant social problems. Author conducted oral inspection and questionnaire for the aged in some welfare facilities in Gyeongnam location from December 2005 to February 2006 to improve quality of life and oral hygiene of the aged. Through gathered data, the actual condition of oral hygiene management on the aged person in welfare facility was evaluated as fundamental data for project development on oral hygiene of aged person. Through the analysis of inspected data, the following conclusions are derived. 1. Management status of oral hygiene is mostly not good, and toothbrushing per day is 'one time' for the most cases. 2. In free-of-charge facility, monthly allowance is 'under 50 thousand won' for the most cases. 3. Time for visiting oral treatment facility is on 'when toothache is occurred' for the most cases. For treatment content, 'prosthetic dentistry' takes 36.8% in charged facility, and 'tooth extraction' is 27.0% for free-of-charge facility. 4. Average DMFT index of the aged in charged facility is 16.81, and free-of-charge facility is 21.71. 5. Average number of functional teeth in charged facility is 15.22, and free-of-charge facility shows 7.29. 6. Average number of remained teeth in charged facility is 15.71, and the umbe in free-of-charge facility is 9.04. 7. Average number of extractable teeth in charged facility is 0.48, and for free-of-charge facility, the number goes up to 1.70.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.2
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• pp.61-68
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• 2004

Electric stimulation of teeth has been used for assessing pulp vitality. The principle is based upon the assumption that a subject feels the pain produced by electrical current stimulation of intradental nerve. Because of very high and wide range of impedance of the enamel, it is very difficult to determine stimulation levels regardless of teeth status. Most pulp testers adopt voltage stimulation method and thus, their stimulating threshold levels significantly depend on each individual. Therefore, a constant current stimulator is necessary to minimize the effect of wide variation due to different enamel thickness. And it is also necessary to test teeth vitality with a wide current range regardless of tooth impedance. In this study, we constructed a burst-wave type pulp tester to reduce the pain using a current stabilizing circuit with the maximum current of 150 uA.