Jia, 21, has always been proud of having a mouthful of white and beautiful teeth, but in the past six months, she found that her lower jaw front teeth have gradually become crowded and uneven. Last week, she came to the stomatology department with confusion, and after examination, it was found that Jia Jia had 28 teeth in her mouth without any abnormalities, so she was asked to take a surface tomography film, which showed that in addition to the 28 teeth that had grown, there were still four unerupted teeth at the end of the upper and lower left and right arches, and these two teeth in the lower jaw were growing forward, which was the cause of Jia Jia’s teeth becoming uneven from neat. This is the reason why Jia Jia’s teeth became uneven. It turns out that we humans will grow four third molars after the age of 16, when the physical and psychological development of human beings is close to maturity, so it is seen as a symbol of the “arrival of wisdom”, so it is called “wisdom teeth”. In the process of human evolution, as food becomes more and more refined, the burden on the jawbone decreases accordingly, resulting in a continuous decrease in the amount of bone in the jaw, but the volume of the teeth does not decrease, which eventually makes the teeth erupt in insufficient positions, with some completely buried in the jawbone, some partially buried and partially erupted, and some fully erupted but positioned either to the buccal side or to the lingual side. In terms of the direction of growth of wisdom teeth, there are vertical, horizontal, oblique forward and oblique backward. Of course, there are a few people who have normal wisdom teeth. 14-18 years old is the most active period of wisdom teeth eruption, if the amount of bone and teeth in the jaw is not balanced, there is not enough space for wisdom teeth eruption, and the propulsion of wisdom teeth eruption movement will cause crowding and uneven alignment of teeth. In addition, the blockage and ectopic eruption of wisdom teeth will cause the accumulation of food residue around the crown and between the second molar, leading to pericoronitis, caries of the second molar and periodontitis between the two teeth; the blockage and ectopic eruption of wisdom teeth will also cause repeated biting of the buccal mucosa and erosion, ulceration and cancer; the tilted forward eruption of wisdom teeth will cause root resorption of the second molar; the completely blocked wisdom teeth may form Tooth-bearing cysts. To avoid the above, wisdom teeth that do not erupt normally or are not functional should be extracted as soon as possible.