Wisdom teeth are the third molar, the most posterior tooth in the mouth. They erupt after the age of 16, and are called wisdom teeth because they emerge when the human mind matures, as opposed to the milk teeth that emerge in early childhood and the permanent teeth that are replaced in childhood. The eruption of wisdom teeth varies greatly from one person to another, from 20 years of age to 40 or 50 years of age, and of course, some people do not grow them throughout their lives. If all the wisdom teeth can grow, there should be four, one on the top and one on the bottom, not all four wisdom teeth are erupted, many wisdom teeth can not even fully erupt, this situation is called wisdom teeth obstruction. Obstructed wisdom teeth are very common in the oral cavity, and these obstructed wisdom teeth are not well connected to the surrounding soft tissues, which can easily form blind pockets, where bacteria can accumulate, often resulting in pericoronitis. When pericoronitis occurs, there is significant swelling and pain. It is also associated with interstitial infection, restricted mouth opening, and systemic symptoms, so it is important to treat pericoronitis promptly. For pericoronitis, the first step is to do systemic anti-inflammatory treatment with oral anti-inflammatory drugs, such as roxithromycin and metronidazole. Secondly, local irrigation treatment should be carried out, using 3% hydrogen peroxide and saline to alternate local irrigation, and then iodine glycerin should be applied locally to reduce inflammation. After systematic treatment, wisdom tooth pericoronitis will usually heal in about three to five days. When the area around the wisdom tooth is no longer swollen and painful, the wisdom tooth should be extracted in time to prevent the recurrence of pericoronitis. For blocked wisdom teeth, it is important to do early examination and early preventive extraction so as to prevent the occurrence of oral diseases such as pericoronitis of wisdom teeth.