Wisdom teeth, the third molars of humans, usually erupt at the age of 18 to 25. As the human jaw bone degenerates and becomes smaller without corresponding changes in the size and number of teeth, the last erupted third molar is often blocked because there is no space for eruption, which can be manifested as partial eruption, mal-eruption, or complete buried blockage. The incidence of wisdom teeth obstruction is high, and its harm is mainly manifested as the following: 1. recurrent episodes of pericoronitis. The soft tissue around the crown of the blocked wisdom tooth forms a blind pocket with the tooth, causing the accumulation of food and bacteria, and when the resistance decreases, pericoronitis is inevitable. The general anti-inflammatory treatment can treat the symptoms but not the root cause, so pericoronitis will recur. 2.Tooth decay. It is easy to accumulate food residue between the wisdom tooth and the second molar in the wrong position, and it is not easy to clean, which can form caries in several months, and directly destroy the tooth tissue, and even cause pulpitis and periapical inflammation in the neighboring teeth. 3.The blocked wisdom teeth often cannot establish normal occlusal relationship with the opposite jaw teeth, which can lead to TMJ popping, painful mouth opening, night grinding and other symptoms for a long time, which has a great impact on the physical and mental health of young adults. 4. There is evidence that some obstructed wisdom teeth are the foci of some trigeminal neuralgia. Removal of obstructed wisdom teeth does not have any adverse effects on the functions of chewing and speech, plus extraction is the most effective way to treat obstruction, therefore, it is recommended to remove the obstructed wisdom teeth causing the above mentioned hazards as early and decisively as possible.