• Restorative Dentistry and Endodontics
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• v.28 no.5
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• pp.419-424
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• 2003

이 연구의 목적은 원래의 치수조직과 유사한 조직을 재생하기 위한 pulp tissue engineering의 한 방법으로 건전한 조직으로부터 배양된 치수세포와 쥐의 조섬유세포(NIH 3T3 cell)를 Rat tail type I collagen solution에서 3차원적으로 관찰하기 위한 것으로, 콜라젠 젤의 수축량과 세포의 증식 량을 비교하였으며, 또한 마모된 사람치아의 표면과 배양용기에서 두 세포의 증식 량을 비교하여 다음과 같은 결과를 얻었다. 1. 콜라젠 젤에 NIH 3T3 세포를 배양한 경우 그 수축량은 최소였으나, 치수세포를 배양한 경우 그 수축량은 현저하였다. 2. 서로 다른 수의 치수세포를 콜라젠 젤에서 배양시킨 경우 세포 수가 많을수록 수축량이 증가하였으며, 세포가 없는 콜라젠 젤은 수축하지 않았다. 3. 치수세포를 콜라젠 젤에서 18일간 배양시킨 후 세포의 증식은 거의 없는 반면, NIH 3T3 세포는 계속 증식하였다. 4. 마모된 사람 치아 표면과 배양 용기에서 치수세포와 NIH 3T3세포를 배양한 경우 NIH 3T3세포가 치수세포에 비해 빠르게 증식 하였으며 , 특히 사람 치아의 표면에서 NIH 3T3세포가 현저히 빠른 증식을 보였다. 이상의 결과는 치수세포를 type I collagen gel에서 3차원 적으로 배양 후 치수조직의 재생을 유도하는 pulp tissue engineering에 관한 연구에 발판이 될 것으로 사료된다.

• Anatomy & Biological Anthropology
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• v.26 no.1
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• pp.41-49
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• 2013

Dental epithelial and mesenchymal cells that form the teeth undergo dynamic changes in cell cycle during tooth development and morphogenesis. Although proliferation has been known as a key event during odontogenesis, the cell cycle phases and their relations with the complicated molecular mechanisms of tooth development are not fully understood yet. This study comparatively examined the expression patterns of Ki-67, cyclin A, and cyclin D1 during tooth development in the mouse incisor and molar in order to identify the cell-cycle characteristics during odontogenesis. We found that Ki-67 and cyclin A were expressed in the proliferating cells in the dental epithelial and mesenchymal tissues at the bud, cap and bell stages. Cycln D1 showed distinct expression in the incisor odontoblast region and the enamel knot, in which Ki-67 nor cyclin A was expressed. Our results provide specific information on the cell cycle phases during tooth development that may provide clues to relate them with the complex odontogenic mechanisms. Furthermore, we suggest that our findings enlightened the previous studies on the incisor odontoblasts and the enamel knot during tooth development.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.4
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• pp.421-426
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• 2000

조직공학은 결손된 조직의 구조 및 기능을 신속히 수복할 수 있도록 적절한 생체소재, 세포, 활성인자 세가지 구성요소를 적절히 조합하는 것이다. 이렇게 하므로써 결손된 조직을 대체할 수 있는 세포에 대한 부착, 이동, 증식, 분화조건을 최적상태로 만들어 주는 것이다. 이러한 관점에서 치아임플랜트의 조직 공학적 적용은 다음 몇가지 관점을 고려할 수 있다. 첫째, 인공치아 임플랜트도 넓은 의미에서 그 자체로서 조직공학의 범주에 들어간다고 할 수 있다. 따라서 결손된 치아의 구조 및 기능을 신속히 회복시킬 수 있도록 조직공학적인 관점에서 검토할 수 있다. 생체소재는 표면에너지의 관점에서, 세포는 골모세표와 섬유모세포관점에서, 활성인자는 세포분화 촉진인자의 관점을 고려할 수 있다. 둘째, 치아임플랜트의 기능회복 촉진을 위한 조직공학기법을 부가적으로 적용하는 것이다. 임플랜트와 생체조직사이에 기능성 조직을 신속히 형성시키므로써 임플랜트의 기능회복을 촉진하는 적절한 생체소재, 세포, 활성인자를 적절히 이용하는 정통 조직공학기법을 적용하는 것이다.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.191-200
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• 2009

Dental Pulp Stem Cells are superior to other types of adult stem cell. Because of teeth are easy to access and are extracted throughout life. A supernumerary tooth is an important clinical problem found in various populations of the world. The incidence of supernumerary teeth varies depending on the literature source. Pediatric dentists are routinely extracted them. However, no studies have been reported regarding Dental Pulp stem cells in a supernumerary tooth, and we failed to note that a valuable source of human stem cell. Herein, we tried to show that a supernumerary tooth contains cells that display the characteristic features of stem cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.290-303
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• 2006

Tooth eruption is a complex and tightly regulated process that involves cells of the tooth organ and the surrounding alveolus. Osteoclast precursors must be recruited into the dental follicle prior to the onset of eruption. This function of dental follicle may be regarded as the ability of bone remodeling characterized by the interaction of osteoclasts and osteoblasts. This is because tooth eruption is a localized event in which many of the genes required for eruption are expressed in the dental follicle. RANKL is a membrane-bound protein that is a member of the TNF ligand family. which is present on bone marrow stromal cells and osteoblasts, and induces osteoclast formation and activation from precursor cell. The biologic effect of RANKL is inhibited by OPG and, in bone, the relative ratio of RANKL and OPG modulates osteoclastogenesis. To evaluate the roles of RANKL and OPG in tooth eruption and the relations with the expression pattern of Runx2, in situ hybridization was performed with mandibles of mice at postnatal stage 1, 3, 5, 7, 9 and 11. mRNA of RANKL, OPG, and Runx2 are expressed in dental follicle and surrounding tissue from P1 to 11. To determine the sites of osteoclastic activity during tooth eruption, mandibles were dissected. Peak osteoclastic activity in alveolar bone along the occlusal and basal regions was observed from P5 to 9, with osteoclasts in these regions being large and strongly TRAP-positive The specific spatio-temporal expression patterns of RANKL, OPG, and Runx2 in our study suggest that tooth eruption could be progressed through the interactions of molecular signaling among dental follicle, dental organ and alveolar bone, furthermore it means that dental follicle is quite important in tooth eruption In addition, it indicates that these genes (RANKL, OPG, and Runx2) play critical roles in tooth eruption.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.196-206
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• 2005

This study was undertaken to investigate the effect of vitamin C deficiency on the orthodontic tooth movement and bony remodeling processes. Thirty six male guinea pigs were divided on the basis of the given amount of vitamin C (normal group: 5mg/day, deficient group: 0.2mg/day) and 75gm of force was applied to the maxillary incisors. Experimental animals were sacrificed at day 0. day 1 day 3, day 5. day 7 and day 14 after force application and the amount of tooth movement was measured and tissues were studied histologically. The results showed that the amount of collagen fiber in the periodontal ligament and alveolar bone of the deficient group was less than that of the normal group. In the stretched side. the osteoblastic activity and alveolar bone formation of the normal group increased in a time dependent manner during experimental periods, but the deficient group showed less activity and formation. The amount of tooth movement in the deficiency group was more than in the normal group at day 0. day 1, day 3, day 5, and day 7. According to the above results, a deficiency of vitamin C resulted in a defect of collagen synthesis of the periodontium and inhibition of bone formation and stimulation of bone resorption with rapid tooth movement in early periods of force application.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.645-650
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• 2004

Calcifying odontogenic cyst(COC) is a rare developmental odontogenic cyst, which shows diverse classification and terminology. Cystic epithelial lining of COC is composed of basal cell layer of columnar cells and overlying layer of stellate reticulum. In the epithelium, ghost cells that might induce adjacent mesenchymal tissue to develop dental organ are shown characteristically. In spite of low rate of recurrence, we have to get a histopathological examination so that odontogenic lesions may recur without fully curettage of lining epithelium. 7-year-old male child came pediatric dentistry in wonkwang university dental hospital in order to check the delayed eruption of left maxillary central incisor. Radiographic examination revealed a well-defined radiopaque mass, overlapping impacted left central and lateral incisor crown. Enucleated mass was tooth-like features and also had epithelium lining. Results of histopathologic procedure, we saw the lots of ghost cell and proliferating hard dental tissues. Also we saw the cystic epithelium cells. It revealed diagnosis of the COC associated complex odontoma. For this reason one should consider of COC when patients present odontoma-like lesion with impacted tooth.

• The Science & Technology
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• v.34 no.4 s.383
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• pp.20-21
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• 2001

리젠바이오텍은 배ㆍ피부 등 생체조직을 파괴시키거나 이에 필요한 생리활성물질 및 촉진제를 개발하는 조직공학분야의 바이오벤처기업이다. 이 회사의 연구팀은 지난 5년동안 키토산을 이용해 각종 세포배양 연구를 하던중 최근 3차원 세포배양을 용이하게 할 수 있는 '다공성 키토산 구슬'을 개발하는데 성공했으며 지난해에는 자연치아 특성을 살린 혁신적인 인공치아 제조기술을 개발하기도 했다.

• The Journal of the Korean dental association
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• v.45 no.6 s.457
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• pp.370-376
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• 2007

"내 치아를 백옥 같이 예쁘게 보이도록 해 주세요!" 라는 환자들의 요청을 만족시키기 위해서 개원 치과의사들이 지난 30여년간 치과진료시에 전 세계적으로 이용하고 있는 과산화 수소가 포함된 각종 치아 미백제의독성에 대한 현실적인 문제점을 지적해 보면서 과학적인 견지에서 현대 분자생물학이나 세포생물학이 제공할 수 있는 해결방안을 제시하고져한다.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.394-399
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• 2000

Odontoma is defined as a benign odontogenic tumor containing enmel, dentin as well as cementum. It has come to mean a growth in which both the epithelial and the mesenchymal cells exhibit complete differentiation. Most authorities accept the view today that the odontoma represents a hamartomatous malformation rather than a true neoplasm. The etiology of odontomas is uncertain but hypothesized to involve local trauma, infection, inheritance or mutant gene. The odontomas often cause various disturbances in the eruption and position of the teeth. The steps in removal of an odontoma in close relation to an adjacent impacted normal tooth should comprise 1) removal of odontoma and 2) exposure of the impacted tooth. Orthodontic therapy may be applied. Before treatment, the necessary space for the impacted tooth should be evaluated. If there is lack of space in the dental arch, orthodontic treatment should be carried out before operation.