Orthokeratienized odontogenic cyst (OOC) is a comparatively unusual developmental odontogenic cyst arising from odontogenic epithelium. Recurrence has rarely been noted, and has been reported in less than 2% of cases. Epidermoid cyst (EDC) is a benign cystic lesion, which is lined by stratified squamous epithelium and includes keratin debris. They can present anywhere in the body but are rare in the head and neck areas. In this report, we present an uncommon case of simultaneous occurrence of OOC in mandible and EDC around the areas of both ears in a patient who has no history of genetic syndrome.

Odontogenic cysts are classified into inflammatory and developmental origins. The most common representative inflammatory cyst is periapical cyst and the most common representative developmental cyst is dentigerous cyst and cyst which show character of tumor is odontogenic keratocyst and cyst of which cystic epithelial lining cells transform to ameloblastoma is unicystic ameloblastoma. Proliferation studies are needed because of various causes, different clinical and pathologic findings. Recently Ki67 has been generally used as cellular proliferation marker, which is closely related to proliferation. Because Ki67 exists in all the time of cell mitosis stage including G1, S, G2, and M, but disappear in resting phase, G0, it is widely used in the evaluation of cell and tissue proliferation activity. The purpose of this study was to establish clinical therapeutic standard through clinical prognosis associated with Ki67 protein expression because of various causes, different clinical and pathologic findings. Immunohistochemical study was performed in selected each 10 biopsy cases through LSAB reaction and HRP system using anti-Ki67 monoclonal antibody. Ki67 expression was mainly seen in the basal layer of periapical cyst, dentigerous cyst and unicystic ameloblastoma, and in suprabasal layer of odontogenic keratocyat, while positive cells appeared very low frequently in unicystic ameloblastoma. Ki67 expression was mainly observed around inflammatory area. Ki67 expression appeared to be independent on the destruction and recurrence of cystic lesion. Conclusively, high cellular proliferation could not represent destruction and recurrence degree of lesion, but this proliferation might be closely associated with circumstance such as inflammation

Odontogenic cysts are classified into inflammatory and developmental origins. The most common representative inflammatory cyst is periapical cyst and the most common representative developmental cyst is dentigerous cyst and cyst which show character of tumor is odontogenic keratocyst and cyst of which cystic epithleial lining cells transform to ameloblastoma is unicystic ameloblastoma. About ten years ago p63 protein that are closely related to p53 protein was found. Authors studied about comparative pattern of expression of p63 protein in periapical cyst, dentigerous cysts, odontogenic kertocysts and unicystic ameloblastomas. Authors selected 10 cases for every four types of cyst and performed immunohistochemical staining by using monoclonal antibody about p63 protein, LSAB(labelled streptoavidin biotin) reactant and HRP(horse raish peroxidase) system. Positive cells about p63 protein were expressed at basal layer of cystic lining epithelium in periapical cysts, odontogenic keratocysts and unicytic ameloblastomas. On the contrary, in dentigerous cysts positive cells were expressed at surfce layer. Perapical cysts and odontogenic keratocysts showed significantly high values of labelling indices.(periapical cyst:72.49%, odontogenic keratocyst:64.72%, dentigerous cyst:8.94%, unicystic ameloblastoma: 5.25%) Odontogenic keratocyst showed the most strong staining intensity and the second was periapical cyst, the third was dentigerous cyst, and lastly unicystic ameloblastoma. Conclusively cause that the positive cells appeared at surface layer in dentigerous cyst reflected the position of epithelium to the enamel, and labelling indices of p63 protein were closely related to proliferative capacity and intensity of expression closely related to the labelling index and thus labelling index was also closely related to proliferative capacity of cystic lining epithelium.

Glandular odontogenic cyst (GOC) is a rare odontogenic cyst, which shows cystic structures lined by stratified squamous epithelium with various thickness. Glandular duct-like spaces lined by eosinophilic cuboidal or columnar cells constitute the epithelial surface. The purpose of this study was to present 7 cases of GOC retrieved from the files of the Department of Oral Pathology, Seoul National University Dental Hospital and to investigate the immunohistochemical expression of cytokeratins (CKs) in the epithelial components. A total of 7 GOCs were reviewed clinically and radiographically and immunostainning for CK 5, 7, 14, 18 and CK-pan were performed. There were five males and two females aged from 36 to 53 years (mean 45 years). Maxilla was more affected than mandibles (6:1). Radiographically, all cases showed multilocular radiolucencies with well-defined borders. Histologically, lining epithelium of GOC was composed of nonkeratinized stratified epithelial cells with focal plaque-like or whirl pool-like thickenings. Surface epithelial layer contained eosinophilic cuboidal cells or mucous cells. Mucin pools of microcystic areas was also detected in the epithelium. Immunohistochemical study demonstrated that epithelium of GOCs was positively reactive for CK 5 7, 14 and CK-pan with a slight variation in their patterns and there was no reaction for CK 18.

The purpose of this study was to evaluate the role of c-fos and c-jun expression in the odontogenic cysts. For this study, 20 subjects of odontoenic dysts: 8 subjects of keratocysts and 12 subjects of periodontal cysts referred to the Dept. of Oral Pathology, School of Dentistry, Kyung Hee University, were used as experimental group, and 5 subjects of normal oral mucosa without any inflammatory changes. were used as control groups respectively. All the tissues of experimental and control group were fixed in neutral formalin solution and embedded in paraffin, serial tissue section were made 5㎛ in thickness and processed in the standard way for immunohistochemical method, using primary antibodies, for c-fos, c-jun was diluted at 1:100 each, followed by the super sensitive non-biotin horse radish peroxidase system with DAB as chromogen application, counter stained with Gill's hematoxylin stainmethod, mounted. And examined under the biologic microscope with the criteria of -(no epithelial stain), +(weak or focal epithelial stain), ++(moderate or focal intensive epithelial stain), +++(intense generalized epithelial staining) for the epithelial, and stromal tissues on each. Attained results as follows. In normal oral mucosa, it is noted that moderate positive responses in cytoplasm and nuclei to c-fos and c-jun protein on each.. In the responses to c-fos, c-jun protein, moderate positive responses in nuclei and cytoplasms of the epithelial lining in keratocysts and periodontal cysts, but more intense reaction is noted on the periodontal cyst compare to that on the keratocysts. In the responses to c-fos, c-jun, it is noted that more intense responses in odontogenic cyst compare to that in the oral mucosa. In the responses to c-fos and c-jun on submucoas of oral normal mucosa, focal epithelial stain was noted. and more intensive reaction was noted on the odontogenic cysts, most in periodontal cysts. This results suggests that c-fos and c-jun protein effected on the induction of development and growth of the cysts

In odontogenic osteolytic lesions, the mechanism involved in inflammation 때d osteolysis is still under debate. We investigated the role 。OL-l ~ -1 ß, -4, -6, -8, TNF- a in the expansion of the odontogenic cysts, by using 50 cases of excised odontogenic cysts. The degrees of inflammation were graded into 2 groups and immunohistochernical stainings were performed, The cytoplasrnic reaction in squamous epithelial cells, stromal cells and infIitrating inflammatory cells was examined. The relationship between the expressions of IL-1 q -1 ß, -4, -6, -8, π-JF- aand the degree of inflammation and the correlation among them were analyzed. 까1e 비Stilαγtic expressions of IL-l ~ IL-l ß and TNF-awere 66.6%, 66.6% and 4O.00Al respeαively and the epithelial exp~않sions of IL-4, -6, -8 were 32.00Al, 38.00Al and 24.00Al respeαively. IL-4, -6 and 용 were positively stained in plasma cells in 38.00Al, endothelial cells in 40.00/0 and neutrophils in 24. 00Al respectively. The expresssion rate of IL-4 in plasma cells and IL-8 in epithelium and neutrophils were inα얹sed in ca않s with marked inflammation. 까1e exp!1않sion rate of IL-1 ßin 피해ocytes and IL-4 in plasma cells were positively correlated with the expæssion of TNF-1 ain histiocytes. π1e expression rate of anti-inflammatory cytokine IL-4 in the epithelium were correlated with the expression of IL-6 in the epithelium and endothelial cells. A1though statistically insi.맑표ìcant， the expression rate of IL-6 were decreased in cases with marked inflammation and nega디vely correlated with IL-8, the proinflammatory cytokine, and the expressions of IL-4 and IL-6 in the epithelium can be considered as inhibiting the inflammatory reaction. These results suggest that the expressions of IL-4 and IL-6 suppress and IL-8 stimulates the inflammatory reaction in Odontogenic Cysts.

Department of Oral Pathology, Dental Science Research Institute, College of Den디'suy， Chonnam National University It is well known that the expansion of radicular and dentigerous cyst is related to the change of osmotic pressure, while the prolifera디on ofthe 비피19 epithelium in odontogenic keratocyst. When the dentigerous cyst and odontogenic keratocyst has secondary infection, they present the loss of unique sπuctures and epithelial hyperplasia. There is a question whether inflammatory reaction affects cystic formation, expansion and their treatment. Present study is to evaluate the relationship between inflammation and epithelial hyperplasia using immunohistochemial study. Followings are result; 1. 까1e age of patients ranged from 10 to 73 years (mean age, 39 years) in radicular 이5t， 10 to 71 years (mean age, 35 years) in dentigerous cyst and 10 to 54 years (mean age, 23.4 years) in odontogenic keratocyst. The sex distribution of patient distributed 32 cases for male and 16 cases for female in radicular cyst, 13 and 10 in dentigerous cyst and equally 5 and 5 in odontogenic keratocyst. 2. Inflammatory cyst in the present study distributed 44/48 cases (9 1.7%) for radicular cyst, 15/ 23 cases for dentigerous cyst and 1/ 10 case for odontogenic keratocyst. 3. Evaluation of inflammatory reaction and antigen expression, ki-67 , cox-2 and glut-1 expression increase in the inflammatory radicular and dentigerous cyst. 4. In odontoge띠c keratocyst, expression of antigens increase regardless of inflammation. Above results showed that inflammation stimulate the proliferation of lining epithelium leading to cystic expansion.

In the expansion of odontogenic cyst, degradation of extracellular matrix and resorp디on of bone are accompa띠ed ， but its mechanism is under debate. The degrees of inflammation and fibrosis were graded in 39 cases of odontogenic cysts. Cytoplasrnic expressions in various cell types according to them were analyzed using immunohistochemis띠， for MMPs and πMPs. In epithelial cells, MMP-2 expression was increased with marked fibrosis(p=O.018) and in stromal cells, MMP-2,-9 and TIMP-2 expressions were slightly higher in cases with mild inflammation and marked fibrosis. Tendencies of positive correlation were found between MMP-2,-9 and TIMP-2 expressions in epithelial cells and between MMP-l and MMP-9 expressions in stromal cells. These results suggest that MMP-l ,-2 ,-9 and TIMP-2 expression might be related to the expansion of odontogenic cysts, and the expression rate of them was different according to cell types and the degree of inflammation and fibrosis.