The stem cell research is emerging as a cutting edge topic for a new treatment for many chronic diseases. Recently, dental stem cell would be possible for regeneration of tooth itself as well as periodontal tissue. However, the study of the cell characterization is scarce. Therefore, we performed the genetic profiling and the characterization of mouse fetus/neonate derived dental tissue and cell to find the identification during dental development. We separated dental arch from mandibles of 14.5 d fetal mice and neonate 0 d under the stereoscope, and isolated dental cells primarily from the tissues. Then, we examined morphology and the gene expression profiles of the primary cells and dental tissues from fetus/neonate and adult with RT-PCR. Primary dental cells showed heterogeneous but the majority was shown as fibroblast-like morphology. The change of population doubling time levels (PDLs) showed that the primary dental cells have growth potential and could be expanded under our culture conditions without reduction of growth rate. Immunocytochemical and flow cytometric analyses were performed to characterize the primary dental cell populations from both of fetus (E14.5) and neonate. Alpha smooth muscle actin (α-SMA), vimentin, and von Willebrand factor showed strong expression, but desmin positive cells were not detected in the primary dental cells. Most of the markers were not uniformly expressed, but found in subsets of cells, indicating that the primary dental cell population is heterogeneous, and characteristics of the populations were changed during culture period. And mesenchymal stem cell markers were highly expressed. Gene expression profile showed Wnt family and its related signaling molecules, growth factors, transcription factors and tooth specific molecules were expressed both fetal and neonatal tissue. The tooth specific genes (enamelin, amelogenin, and DSPP) only expressed in neonate and adult stage. These expression patterns appeared same as primary fetal and neonatal cells. In this study we isolated primary cells from whole mandible of fetal and neonatal mice. And we investigated the characteristics of the primary cells and the profile of gene expressions, which are involved in epithelial-mesenchymal interactions during tooth development. Taken together, the primary dental cells in early passages or fetal and neonatal mandibles could be useful stem cell resources.

This is a case reporL of a ra re mi xed odontogenic tumo r, amelob lastic fibro-odontoma in the poste1'ior of r ight ma nd tlbe A 2-year - olcl ma le pa ti enL was referred to our department ['or large tumorous lesion 011 ri ght mandible Radiograph ic examination s howed la rge radi opaque and rad iolu cent lesion with impacted and unerupted tooth, #44‘ #45 , #46 #85 , AJ'Ler s urgi cal enuclea Li on & cu rettage of t he mass , the tumor was confirmed to ameloblastic fibro-odontoma. lt was composed with c1 enta l orga ns a ncl is la nd of odontogeni c epithelium embedded in a cell - ri ch mesenchymal s troma, AIso‘ we ca rri ed out an immunohi stochemical study. The resul ts s howed positive CK7 staining. and showed weekly positi ve for Bcl - 2‘ Ki - 67 s Laining, while CEA, CK8‘ CKl2, CKl6 showed l1egative, Follow-up studies have shown no tumot recurrence for 2 yea rs ,

Osteoarthrosis in TMJ is known to accompany characteristic features of the craniofacial malformation and malocclusion. In order to explain the mechanism that brings about the typical mandibular changes relating to the frequent clinical symptom, i.e., the limited mouth opening in TMJ patients. The present study investigated the mandibular morphology of the rabbit, also intentional TMJ osteoarthrosis was performed on the TMJ of the rabbits and their morphological changes were observed. A total of 12 New Zealand house rabbits weighing an average of 3 kgwere used and all left side joints were surgically meniscectomized and right side joints were used as controls. The rabbits were sacrificed in one week, two weeks, one month, three months and 5 months after the menisectomy, and the removed TMJs were examined by histological and radiographical methods and analyzed statistically. It was found that the mandibular morphology caused by osteoarthritis in the TMJ was characterized by the decrease in size of the ascending ramus, posterior ramus bowing, deep antegonial notch and thickening of the cortex in inferior and posterior borders of the mandible, that the similar features were also observed in the rabbit mandible. When the menisectomy was performed in the unilateral side of rabbit TMJ, the mandibular changes including the increased depth of antegonial notch and posterior ramus bowing occurred only on the affected side. These data suggested that the limitation of the mandibular movement and altered masticatory pattern by meniscectomy affects the structural remodeling of the mandible and TMJ likely the TMJ osteoarthrosis

The primary growth center (MdPGC) of human fetal mandible was conspicuously distinguished in the soft X-ray view of fetal mandibles.1) As the peripheral adaptive growth of mandible advanced during the postnatal period, the MdPGC became overshadowed by condensed cortical bone. However, in the well-processed radiograms of adult mandible a condensed radiopaque image, measuring 0.5-1.0 cm in diameter, can be observed below the apex of first premolar. In this study we aimed to trace a sclerotic sequela of mandibular primary growth center during postnatal period. Panoramic radiograms of two hundreds adults and soft X-ray views of thirty dry mandible were analyzed by statistical methods. The adult MdPGC was clearly distinguishable from the mental foramen. The area of MdPGC was seldom changed in the older persons, even in the edentulous mandibles. Additionally, the benign lesions of odontogenic cysts and tumors hardly destroyed the original structure of MdPGC, while the malignant tumors of squamous cell carcinoma and metastatic cancer rapidly destroyed and resolved the radiopaque area of the MdPGC.