The document discusses human teeth. It notes that babies have 20 teeth, adults have 32 teeth, and in the mouth there are 28 teeth called incisors, canines, premolars, and molars. It matches the different types of teeth to their functions, such as incisors for chewing, canines for cutting, and molars for tearing. The document also states that losing a tooth can make someone sad, but getting a new tooth can make them happy, and that without teeth we cannot smile, eat, sing or talk properly.