The innermost tooth is called wisdom tooth. If the wisdom tooth has erupted, the innermost tooth is the wisdom tooth. If the wisdom tooth has not erupted, the innermost tooth is the second molar. Wisdom tooth is the third innermost molar on the alveolar bone in the mouth, which is only the eighth molar from the central incisor. It usually erupts at the age of 16 to 25, when the physiological and psychological development of the human body is close to maturity, and the innermost tooth is called wisdom tooth. Generally, adults have three molars, which are called the first molar, the second molar, and the third molar. The third molar is often called wisdom tooth. 1. The judgment of wisdom tooth cannot be based on one's own feeling. It needs to be examined by a formal dentist, and then take a panoramic tomography to see if the wisdom tooth has erupted. Some wisdom teeth have occurred, but are buried in the jawbone and cannot erupt or partially erupt. Some wisdom teeth are congenitally degenerated and cannot be seen in the jawbone. Degenerated wisdom teeth can never erupt. 2. Wisdom teeth and appendix are naturally grown by humans. The appendix is an organ used by humans in primitive times to digest coarse fibers, such as tree roots and other foods, while wisdom teeth are teeth used to chew coarse food fibers, such as tree roots and bark, to help the human digestive system. With the progress of humans, food has become more and more refined, and humans have gradually degenerated unnecessary things. The volume of the jaw has become smaller, and there is almost no growth space for wisdom teeth on the jawbone, and there is no opposing tooth on the upper jaw.