• BMB Reports
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• v.40 no.3
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• pp.368-372
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• 2007

Ghrelin belongs to the family of a gut-brain hormone that promotes food intake and controls energy balance. Recently, it has also been shown to regulate bone formation directly. Dental tissue shares several functional, developmental and anatomical similarities with bone, and in the present study we have investigated the presence of ghrelin in 44 human teeth using immunocytochemistry and radioimmunoassay. Both methods showed that the hormone is present in canines and molars, mainly in the odontoblasts but also in the pulp. Ghrelin could potentially play interesting physiological roles in teeth.

• Imaging Science in Dentistry
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• v.31 no.2
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• pp.109-115
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• 2001

The ameloblastic carcinoma is an extremely rare, aggressive odontogenic neoplasm of the jaws. It is described as an ameloblastoma in which there is histologic evidence of malignancy in the primary or recurrent tumors, regardless of whether it has metastasized. We report an aggressive case of ameloblastic carcinoma of the mandible. A 68-year-old man with the complaint of the left facial swelling and intermittent pain was referred to our hospital. Serial images of panoramic radiograph, computed tomograph, and magnetic resonance imaging showed an ill-defined destructive radiolucent lesion of the left mandible. The lesion had typically aggressive behavior with extensive local destruction of bone and extended to the adjacent soft tissues. Bone scan revealed increased uptakes in the left mandibular body and ramus regions. Histological features were generally resembled with those of an ameloblastoma but with cytologic features of epithelial malignancy.

• Journal of Korean Dental Science
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• v.15 no.2
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• pp.121-131
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• 2022

Ameloblastoma is the most representative epithelial odontogenic tumor in the craniofacial region. Through several studies on Ameloblastoma that have been conducted so far, we have been able to get closer to the reality of Ameloblastoma. However, groundbreaking insight into the pathophysiology of Ameloblastoma has not yet been provided. This review assessed three aspects of five recently published papers on Ameloblastoma: cancer stem cells, calcium signaling, and tumor microenvironment, and compared them with previous studies on tumor physiology, including cancer. In addition, the characteristics of Ameloblastoma revealed by the experimental methods presented in the currently published five papers provide the possibility of Ameloblastoma as a study model in general tumor or cancer studies. Furthermore, the mechanisms of action of the chemicals identified in the studies support their potential as candidates for the second-line treatment of Ameloblastoma.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.4
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• pp.213-220
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• 2009

Purpose: The present study was aimed to examine the usefulness of 18F-FDG PET/CT in the evaluation of cervical lymph node metastasis in patients with oral cancer. Materials and methods: Twenty-two patients who underwent neck dissection to treat oral cancer were subjected for examination. The cervical node metastasis was evaluated by means of clinical examination, CT scan, PET, and histologic examination. By comparing the results of each examination modality with those of histologic examination, it's sensitivity, specificity, positive predictive value, and negative predictive value were determined. Results: The oral cancer was more frequent in males with a ratio of 2.14:1. The sixth decade showed the highest incidence in age distribution with mean of $56{\pm}16$. Histologic findings showed that squamous cell carcinoma was the most common (15 patients), and mucoepidermoid carcinoma (3), malignant melanoma (2), and adenoid cystic carcinoma and ghost cell odontogenic carcinoma (1 each), in order. In most cases, wide surgical excision of the primary cancer and neck dissection was performed, followed by reconstruction with free flaps when necessary. When comparing the results of each examination modality with those of the histologic examination, clinical examination showed sensitivity, specificity, positive predictive value, and negative predictive value at 11%, 85%, 33%, and 58%, respectively. CT scans showed at 67%, 77%, 67%, and 77%, while $^{18}F$-FDG PET/CT at 78%, 77%, 70%, and 83%, respectively. Conclusions: These results suggest that PET is more useful, compared with clinical examination and CT scans, in the evaluation of cervical lymph node metastasis in patients with oral cancer.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1983.05a
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• pp.19.1-19
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• 1983

The dentigerous cyst involving maxilla is rare disease in Otolaryngologic field. A case of 22-year-old male patient involving dentigerous cyst of the maxilla with chronic inflammatory signs has been presented. The occurrence of odontogenic epithelium in the wall of dentigerous cyst is a well known entity. This epithelium usually remains inactive and does not have clinical significance, but these small inactive islands of epithelium may be stimulated, resulting in chronic inflammation, ameloblastoma and squamous cell carcinoma. Therefore correct diagnosis and proper treatment are very important. The authors have recently experienced a case of dentigerous cyst causing a mild disfigulation of face. The cyst was surgically enucleated through sublabial approach.

• Journal of dental hygiene science
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• v.11 no.1
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• pp.55-61
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• 2011

The purpose of this study was to investigate the biological function of ODAM and its signal transduction pathway in the steps of ameloblast differentiation and enamel mineralization. An ODAM recombinant protein was produced and stable ODAM transgenic cell lines were also established using ameloblast-lineage cells (ALCs). To verify the ODAM signal transduction pathway, BAMBI recombinant protein, an inhibitor of BMP2 and BMP receptor 1B (BMPR-1B), was treated and BMPR-1B siRNA was used to silence expression of BMPR-1B. Mineralization was augmented by the ALCs treated with the ODAM recombinant protein and the sense ODAM overexpressing cells. The ALP activity was also increased markedly in the sense ODAM overexpressing cells and the ALCs treated with ODAM recombinant protein. The inactivation of ODAM in the ALCs down-regulated the expression of BMPR-1B, whereas its expression was up-regulated markedly when ODAM was overexpressed. These results provide deeper insights into the process of ameloblast maturation and in enamel mineralization. It also suggested that ODAM augmented enamel mineralization.

• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.144-152
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• 1996

Ameloblastomas are benign epithelial neoplasm of the jaw comprising approximately 1-3.3% of all odontogenic cysts and tumors. Although most are microscopically benign, they are generally considered to be locally aggressive and destructive, exhibiting a high rate of recurrence. Treatments of them contain the conservative treatments on unilocular types and radical treatments on multilocular types. Classifications based on the histologic features of ameloblastoma generally included the follicular, plexiform, acanthomatous, basal cell, uncystic types. However, recently a new and unusual variant has been added by Eversole et. al in 1984, the histologic features of which are characterized by marked stromal desmoplastic proliferation. This is a case report of desmoplastic ameloblastoma in the anterior maxilla of 63 year-old female treated by block excision. This provides a brief review of the literature because of the rarity and unusual radiographic-histologic features of desmoplastic ameloblastoma.

• Restorative Dentistry and Endodontics
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• v.31 no.6
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• pp.437-444
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• 2006

This study was aimed to elucidate the biological function of OD314 (Apin protein), which is related to ameloblast differentiation and amelogenesis. Apin protein, calcifying epithelial odontogenic (pindborg) tumors (CEOTs)-associated amyloid, were isolated from CEOTs, and has similar nucleotide sequences to OD314. We examined expression of the OD314 mRNA using in-situ hybridization during tooth development in mice. Expression of OD314 and several enamel matrix proteins were examined in the cultured ameloblast cell line up to 28 days by reverse transcription-polymerase chain reaction (RT-PCR) amplification. After inactivation and over-expression of the OD314 gene in ameloblast cell lines using U6 vectordriven RNA interference and CMV-OD314 construct, RT-PCR were performed to evaluate the effect of the OD314 during amelogenesis. The results were as follows: 1. In in-situ hybridization, OD314 mRNAs were more strongly expressed in ameloblast than odontoblast. 2. When ameloblast cells were cultured in the diffcrentiation and mineralization medium for 28 days, the tuftelin mRNA expression was maintained from the beginning to day 14, and then gradually decreased to day 28. The expressions of amelogenin and enamelin were gradually decreased according to the ameloblast differentiation. 3. Inactivation of OD314 by U6-OD314 siRNA construct down-regulated the expression of OD314, MMP-20, and tuftelin, whereas over-expression of OD314 by CMV-OD314 construct up-regulated the expression of OD314 and MMP-20 without change in tuftelin. These results suggest that OD314 is considered as an ameloblast-enriched gene and may play the important roles in ameloblast differentiation and mineralization.