Tooth germ invagination from cell–cell interaction: Working hypothesis on mechanical instability

The study presented a theoretical model to explain the early stage of tooth germ development, specifically the transition from a bud to a cap-like shape, which is crucial for tooth design. The model focused on the mechanical interactions between epithelial and mesenchymal cells, suggesting that tightly bound peripheral epithelial cells form an elastic sheet, while mesenchymal cells restrict growth. The study found that differences in growth rates between peripheral and interior epithelial cells, along with the size of the tooth germ, led to spontaneous buckling of the epithelium, resembling the cap-stage form. This provided a new hypothesis for understanding the histological features of tooth germ development.