Acute pericoronitis is a severe infection-related pain in the gum tissue around the crown of a tooth, most commonly in the wisdom tooth, and is therefore called wisdom tooth pericoronitis. The main cause of pericoronitis is poor eruption of the wisdom tooth, which is the last tooth to erupt. As people chew finer and finer foods nowadays, there is not enough room for the wisdom tooth to erupt, which leads to various ectopic eruptions of the wisdom tooth, resulting in gaps around the wisdom tooth. These gaps are particularly prone to retaining food debris and bacteria, which over time can lead to pericoronitis. The treatment of pericoronitis in the acute phase is local irrigation and systemic medication, and after the acute phase, wisdom tooth extraction is considered to cure pericoronitis.