Over the course of evolution, teeth have adapted to different environments based on the changing human diet. There are four types of teeth in the human dental anatomy: incisors, canines, premolars, and molars. They each have different functions of cutting, grinding, crushing, tearing, and chewing food. An incisor has sharp edges to cut the food, whereas the canines are used for holding the food and tear it, the molars are flatter with four ridges and used for chewing, they all aid in the process of preparing the food for proper digestion.