Group 1 - The rise of oral medicine and the "dental revolution" has laid the material and physical foundation for the "smile revolution" through various restoration techniques and the invention of exquisite ceramic dentures [1][4] - The concept of smiling as a social norm is a modern invention, significantly influenced by advancements in science and medicine, particularly in the 18th century [3][4] - Prior to the late 18th century in France, smiling was not socially accepted among the upper class, and the lack of dental care led to a societal norm of not displaying teeth when smiling [4]