Matrix metalloproteinases (MMPs) are proteolytic enzymes involved in degradation of the extracellular matrix.In a previous study, MMP-13 was found to be expressed in pulp implying its involvement in the pathogenesis of dental caries. Two extracted teeth were used. A sound tooth and a tooth with wide range of dental caries were used. Two sections were obtained each from isolated crown and root. Immunofluorescence of the FITC of the MMP-13 in coronal and radicular dentin was analyzed by confocal microscopy. Immunofluorescence signals that were indicative of MMP-13 were observed in coronal dentin of sound teeth and in carious teeth with a wide range of caries. Marked immunofluorescent reaction was observed in the border line of caries infected and affected coronal dentin. MMP-13 expression was not detected in the root dentin. The expressions of MMP-13 in carious dentin imply the roles of MMP-13 in caries progression.
cording to histopathological characteristics. One is composite tumor, and the other is collision tumor. Composite tumor is a lesion showing the combined histopathological characteristics of two or more previously recognized tumor and/or cysts of different categories. Two constituent parts are mixed with each other, and histological transition is often observed. On the other hand, collision tumor is a lesion showing the independent histopathological characteristics of two or more previously recognized tumor and/or cysts of different categories. Two constituent parts are separated each other by connective tissue, and histological transition is not observed. Their origin is still unclear. In this study, a collision tumor was reported. 77-year old woman was referred to CNUH with a neck mass in right submandibular area. Incisional biopsy was carried out, and the patient was diagnosed as collision tumor of squamous cell carcinoma and neurofibroma. After reviewing studies reporting collision tumor from head and neck area, formation of a collision tumor was most frequent from a cervical area and average age is 59.6. A collision tumor commonly lead to misdiagnosis, and the prognosis is not always transparent. The variety symptom of collision tumor has to be kept in mind in the diagnosis and treatment of the lesions in head and neck area.
We report a rare case of intraosseous epidermoid cyst in mandibular body. A non symptomatic patient without trauma history had a cystic lesion on mandible close to the third molar. The lesion was enucleated while extracting of left lower third molar. The microscopic findings were consistent with an epidermoid cyst. Key words：Epidermoid Cyst, Intraosseous, Mandible
The trauma of incisive canal associated dental implant placement in the anterior maxilla can cause the nasopalatine duct cyst. It is difficult to identify the nasopalatine duct cyst or the location of the incisive canal, only using periapical radiograph or panorama radiograph. So it is necessary to take computed tomography scan for an analysis on the relation between the implant and the incisive canal. This case report present the patient had the nasopalatine duct cyst following the placement of dental implant in the anterior maxilla, and was undergone implant removal and cyst enucleation with bone graft.