Читать книгу An Illustrated Guide to Oral Histology - Группа авторов - Страница 16

The bud stage is the first stage of tooth development. It represents the first epithelial intrusion into the ectomesenchyme. The cells of the epithelium show minimal changes and the ectomesenchymal cells surround the epithelial bud. Due to the ectomesenchymal condensation (a process in which the epithelial bud propagates into the ectomesenchyme), the density of the cells increases near the epithelial outgrowth. This condensation is owed to the increased mitotic activity carried in the cells of the tooth bud and mesenchymal cells surrounding it. These buds develop at the distal side of the dental lamina and each bud represents a group of cells at dental lamina's end. The epithelial part is separated from the mesenchyme by a basement membrane. The ectomesenchyme surrounding the tooth bud is called the dental follicle or sac whereas the area directly subjacent to the condensation is called the dental papilla. The dental follicle is ultimately responsible for the formation of cementum, periodontal ligament (PDL), and alveolar bone. The dental papilla is responsible for the formation of dental pulp and dentin.