RESUMO
Background: Altered molecular signaling pathways in ameloblastoma have been identified to play a pivotal role in the mechanism of oncogenesis, differentiation, and tumor progression. Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin pathway is one of the signaling pathways that are associated with the pathogenesis of ameloblastoma. Phosphatase and tensin homolog (PTEN) controls cell migration and proliferation. It monitors the level of the Akt and maintains cellular integrity. The present study was aimed to study the immunoexpression of PTEN in ameloblastoma to understand its role in the pathogenesis of ameloblastoma. Materials and Methods: Twenty cases of ameloblastoma and ten cases of normal tooth germ were subjected to immunohistochemical staining against PTEN. Results: Strong PTEN immunopositivity was seen in the tooth germs, while weak positivity was seen in the ameloblastoma. The immunoscore for PTEN was calculated by adding the percentage score and the intensity score. Seventeen cases showed the reduced PTEN expression in the epithelial component of ameloblastoma. The unpaired t-test showed a statistically significant difference in the mean PTEN immunoscore in tooth germ and ameloblastoma. Conclusion: The study showed reduced PTEN immunoreactivity, which plays a role in the pathogenesis of ameloblastoma, through Akt pathway
RESUMO
Regenerative medicine is based on stem cells.The dental pulp contains the progenitor/stem cells which have the self renewal capability, multi-lineage differentiation capacity and clonogenic efficiency. Dental stem cells can generate many types of tissues including bone, nerve, cartilage, teeth and fat. However teeth can actually be a rich source of stem cells. Deciduous teeth or the so-called milk teeth and wisdom teeth have an abundance of stem cells. Stem cells have become the rage across the world after the health potential emerged some years ago. For years scientists all over the world have been working on possibilities of using these stem cells to regenerate human cells which are damaged due to illness, developmental defects and accidents. Recently stem cell banks are present, and even some of these banks do not only freeze cord stem cells but also dental stem cells of baby teeth. Hence this paper reviews the history, current concepts, evolution of stem cells in dentistry, dental stem cell banking in India, characterization of the stem cells in dentin regeneration and stem cell therapy in dentistry.