Central odontogenic fibroma (COF) is an uncommon slow growing benign neoplasm that is derived from the mesenchymal tissue. Differential diagnoses include fibrous dysplasia, calcifying odontogenic cyst, and central ossifying fibroma. Clinically, the lesion shows expansion of cortical bone. Radiologically, unilocular or multilocular lesion with well-defined borders is found. Histologically, fibroblastic tissues with bundle of collagens including inactive odontogenic epithelium can be observed. In this case report, a 45-year-old male with central odontogenic fibroma of the maxilla is examined. The lesion was surgically removed without any postoperative complications. In order to diagnose the disease properly, histopathologic analysis was performed.

연구기관의 협력 네트워크 구조 및 특징은 기관의 학문적 성과에 영향을 미친 다. 특히 한국의 정부출연연구기관은 선도적인 국가 연구개발 수행 주체로서 효율적인 협력 체제를 구축해야 할 필요가 있다. 본 연구는 효율적인 네트워크 구조로 논의되어 온 좁은 세상 구조와 노드간 특징을 나타내는 중심성을 한국 과학기술계 정부출연연구기관 협력 네트워크에 적용하였다. 2010년∼ 2019년 과학기술계 정부출연연구기관의 논문 데이터를 바탕으로 좁은 세상 구조적 특징 및 중심성과 논문 성과 간 관계를 네트워크 분석과 Feasible GLS 회귀모형을 이용하여 분석하였다. 그 결과, 정부출연연구기관 협력 네트워크는 좁은 세상 구조를 취할수록 학문적 성과 에 유의미한 양의 성과를 거둘 수 있는 것으로 나타났다. 또한, 직접적인 연결 정도를 나타내는 중심성은 양의 유의성을 보였으나, 중개자 정도를 나타내는 중심성은 유의하지 않거나 음 으로 유의했다. 교류 협력하는 기관의 수가 많을수록 논문 성과가 높았으며, 협력의 중심지 역할을 하는 기관과 협력 관계인 기관의 성과가 높다. 또한, 정부출연연구기관의 협력 네트워크가 좁은 세상의 특성을 강하게 가질수록 연구 성과 창출에 효과적이라는 것을 규명하였다. 본 연구는 기존에 효율적인 네트워크 구조로서 논의되던 좁은 세상 구조와 중심성을 정부출연연구기관 협력 네트워크에 적용하고 성과와의 관계를 실증 분석할 뿐 아니라 정부출연연구기관 간 연 구개발 협력관련 정책 및 전략 수립에 시사점을 제시한다.

Central odontogenic fibroma(COF) is a very rare benign tumor that accounts for 0.1-1.5% of all odontogenic tumors. Most COF develop in the molar-premolar region in the mandible and anterior to the first molar in the maxilla. Radiographically, the lesions appear as a unilocular or multilocular radiolucent image. Some maxillary lesions have cleft like depression in the palatal mucosa are found. This report presents a COF with external root resorption and palatal soft tissue depression on CBCT images. A 27-year-old man referred for evaluation of unilocular radiolucent lesion with external root resorption in the right anterior maxillary region. On clinical examination, the right anterior maxillary teeth responded positive to the cold stimulus and its response to the vitality test remained within the normal range. On radiographic examination, osteolytic lesion with external root resorption and palatal mucosa depression as a radiolucent shadow. After excisional biopsy, the lesion was diagnosed as COF in histopathologic examination. There was no recurrence at a follow-up 10 months.

본 연구의 목적은 ‘한국 시·군·구의 네트워크 중심성 측정’이다. 이러한 연구목적의 달성을 위해 전국 229개 시·군·구 간의 중심성 크기를 ‘2015년 인구주택총조사’의 전국 229개 시·군·구의 통근통행 O-D 행렬을 이용하여 점수 형태로 측정하였다. 본 연구에서 전국 229개 시·군·구를 대상으로 중심성 점수를 측정한 것은 기존의 연구 중에는 전국 229개 시·군·구 전체를 대상으로 조사한 사례가 없기 때문이다. 본 연구에서 측정한 중심성은 세가지인데, 연결정도 중심성과 고유벡터 중심성, 그리고 연결정도 중심성과 고유벡터 중심성을 일반화시킨 보나시치 베타 중심성이 그것들이다. 본 연구에서 연결정도 중심성, 고유벡터 중심성 및 β＜ 0 인 보나시치 베타 중심성을 사용하여 전국 229개 시·군·구의 세가지 중심성을 구하고, 이 세가지 중심성의 결과값을 비교한 결과, 지역 간 상호관계는 기존 연구에서 나타난 상호보완적 관계가 아니라 상호경쟁적 관계임이 명확하게 드러났다. 특히, 지역 간 상호관계가 상호경쟁적 관계일 경우 보나시치 베타(β＜ 0) 중심성으로 측정하여야 정확성이 높은 중심성 결과값을 얻을 수 있는 것으로 나타났다.

Using network betweenness centrality we attempt to analyze the characteristics of Seoul metropolitan subway lines. Betweenness centrality highlights the importance of a node as a transfer point between any pairs of nodes. This ‘transfer’ characteristic is obviously of paramount importance in transit systems. For betweenness centrality, both traditional betweenness centrality measure and weighted betweenness centrality measure which uses monthly passenger flow amount between two stations are used. By comparing traditional and weighted betweenness centrality measures of lines characteristics of passenger flow can be identified. We also investigated factors which affect betweenness centrality. It is the number of passenger who get on or get off that significantly affects betweenness centrality measures. Through correlation analysis of the number of passenger and betweenness centrality, it is found out that Seoul metropolitan subway system is well designed in terms of regional distribution of population. Four measures are proposed which represent the passenger flow characteristics. It is shown they do not follow Power-law distribution, which means passenger flow is relatively evenly distributed among stations. It has been shown that the passenger flow characteristics of subway networks in other foreign cities such as Beijing, Boston and San Franciso do follow power-law distribution, that is, pretty much biased passenger flow traffic characteristics. In this study we have also tried to answer why passenger traffic flow of Seoul metropolitan subway network is more homogeneous compared to that of Beijing.

Central odontogenic fibroma(COF) is an extremely rare benign tumor that accounts for 0.1% of all odontogenic tumor. COF is regarded by the World Health Organization(WHO) as a benign odontogenic neoplasm derived from mesenchymal odontogenic tissue. The lesion occurs most commonly in the mandible and patients ranging in age from11 to 80years with mean age of 34years. In this article, we report two case of COF. Case I was associated odontoma and impacted tooth. Odontoma and impacted tooth was removal under general anesthesia. After microscopic examination, finally we diagnosis this lesion as COF. Patients of case II showed radiolucent lesion at the mandible. Lesion was enucleated under general anesthesia. After microscopic examination, finally we diagnosis this lesion as COF. The patients which we presented did not complain any specific complications, showed good prognosis.

Mucoepidermoid carcinoma, a malignant neoplasm of salivary gland, rarely arises within the jaws. Differential diagnosis should include an odontogenic cyst because the central mucoepidermoid carcinoma usually reveals either an unilocular or multilocular radiolucency with hyperostotic border. Long-term follow-up is needed due to late recurrence and clinical slow progress like other salivary gland tumors. We would like to report an unusual case of central mucoepidermoid carcinoma with a review of literature.

The ossifying fibroma (OF), with the microscopic features of trabuclae or spherules of bone or cementum-like material in a cellular fibrous connective tissue stroma, is one of the most common benign fibro-osseous lesions in the jaw bones. The OF often occurs in patients from 20 to 40 years of age, which is a definite female predilection. The mandibles are involved far more often than the maxillas, especially the pre-molar and molar regions. It is slow-growing, bone producing, asymptomatic and well-demarcated. The OF is a disorder of odontogenesis or osteogenesis ascribed to bone marrow stroma cells (BMSCs) abnormality. However, the detailed mechanisms of OF’s oncogenesis, cytodifferentiation, and tumor progression remain unknown. In this article, we reported a huge central OF on the anterior mandible. The lesion was enucleated and peripheral ostectomy was done via intraoral approach and reconstructed with vascularized iliac block bone graft. After 25 months of follow up, the tumor had not recurred. This case shows that OF may be successfully treated by conservative surgical enucleation and peripheral ostectomy.

The osteoblastic activity of carcinoma is restricted in osteoblastic metastasis, common in the patients with prostate cancer, whereas its mechanism and the factors involved are unknown. Here, we present a case of central adenocarcinoma showing the osteoblastic activity in the mandible of the 80-year-old Korean male who had suffered from the paresthesia of lower lip during four mouths. Clinically the overlying oral epithelium was intact, but the radiologic images revealed the ill-defined radiolucent intraosseous lesions in left ascending ramus. Microscopically, the mandibular lesion was composed with carcinoma of ductal or glandular differentiation but lack typical features of any epithelial salivary gland malignancies. Intriguingly abundant new bone formation was found in the stroma, but the tumor cells expressed no reactivity for prostate-specific antigen(PSA). The patient had low ionized calcium level, normal serum alkaline phosphatase and PSA level. Positron emission tomography-computed tomopraphy scan revealed the benign prostatic hyperplasia, but failed to trace the primary site of tumor other than mandible. Therefore, pathologically diagnosis for the lesion was informed as adenocarcinoma, not otherwise specified(NOS). Because occult primary tumor associated with osteoblastic metastasis cannot be completely ruled out, periodic and careful check-ups for the patient should be performed.

The central granular cell odontogenic tumor is a rare benign odontogenic neoplasm of uncertain hisotogenesis characterized by varying amounts of eosinophilic granular cells and apparently inactive odontogenic epithelium with variable presence of calcified tissue. We present a case of central granular cell odontogenic tumor involving the maxilla of 35-year-old man with immunohistochemical characterization of granular cells. In microscopic view, the granular cells densely packed in sheets and lobules with abundant eosinophilic, granular cytoplasm and eccentric round-to-ovoid nuclei revealed immunoreactivity for vimentin, α1-antitrysin and CD68, and NSE but not for cytokeratin and S-100 protein while the interspersed odontogenic epithelial cells were positive for cytokeratin only. Granular cells also revealed strong PAS staining. Numerous concentric structured round to ovoid calcified aggregates were also noted. The lesion was treated with excision without recurrence for 8 years. Our immuohistochemical staining findings also suggest that the granular cells of central granular cell odontogenic tumor are mesenchymal in origin with possible histiocytic differentiation

Central granular cell odontogenic tumor (CGCOT) is a rare benign odontogenic neoplasm, with approximately 30 cases having been reported. The pathogenesis of CGCOT as well as the designation of this lesion is controversial because of unknown histogenesis of the granular cell. We present an additional case of CGCOT involving the mandible of a 50-year-old Korean man who complained of asymptomatic swelling of the right buccal gingiva. Current lesion is microscopically characterized by densely packed polyhedral granular cells surrounding interspersed islands or strands of odontogenic epithelium. Immunohistochemically, granular cells were positive for Vimentin and CD68, and negative for cytokeratin and S-100. These features support a mesenchymal origin for the granular cells as other results previously reported.

교사들이 과학 교수학습에 대한 새로운 신념을 형성하려면, 학생들에게 제공할 것과 유사한 교수학습 방법을 직접 경험할 필요가 있다. 지구과학 교사 20명을 포함한71명의 한국 중등 과학교사들이 미국 중부 아이오와 대학교에서 실시된4주간의 여름 연수 프로그램에 참가하였고, 학생중심 수업에 대한 여러 가지 수업 및 활동을 경험하였다. 아울러 교사들은 각자 학생 역할과 교사 역할을 맡아서 모의 수업을 진행함으로써 학생중심 수업을 실제로 체험하기도 하였다. 본 연구는 교사들에게 제공된 이러한 교사 재교육프로그램에서의 경험이 교사들의 과학 교수 학습에 대한 신념에 어떤 영향을 미쳤는지를 조사하였다. 연구대상이 된 신념은 구체적으로 과학학습의 목적, 교사와 학생의 역할 그리고 수업에 대한 것으로 총 7문항으로 제시되었다. 즉 교사들의 교사중심적인 교수, 학습에 대한 신념의 양상이 학생중심으로 옮겨갔다는 점이다. 물론 그 변화가 교사중심에서 완벽하게 학생중심으로 옮겨간 것을 의미하는 것이 라기보다 교사중심에서 탈피하거나 이에 반하는 쪽으로 변화했다는 것에 의의가 있다. 한편, 연수에서 경험한 협동학습이 참여 교사들의 긍정적인 방향으로의 신념변화를 초래한 주요 요인들 중의 하나였음을 보고한다.

The aim of this study is to analyze the green-tourism centrality considering spatial interaction using Gravity Model and social network method. The degree centrality and prestige centrality were applied as green-tourism centrality index. The rural amenity resources and human resources were counted as attraction factors, and a distance among villages was used as friction factor in gravity model. The weights of rural tourism amenity resources were calculated using the analytic hierarchy process(AHP) method and applied to evaluate green-tourism potentiality. The distance was measured with the shortest path among villages using geographic information system(GIS) network analysis. The spatial interaction from gravity model were employed as link weights between nodal points; a pair villages. Using the spatial interaction, the degree-centrality and prestige-centrality indices were calculated by social network analysis and demonstrated possibility of developing integrated green-tourism region centered on high centrality villages.