In the dental clinic, we often encounter pregnant women with painful expressions coming to see their teeth, either with swollen teeth or toothache, which cannot be treated with injections or medicines. The most common dental disease in this part of the population is pericoronitis of wisdom teeth, followed by pulpitis, apical inflammation, etc. The soft tissue inflammation around the crown of the wisdom tooth (third molar) is called pericoronitis. It often occurs in young people aged 18-25 years and is one of the common oral diseases. The main symptom is painful swelling of the soft tissues around the crown of the tooth. If the inflammation affects the masticatory muscles, it can cause varying degrees of mouth opening restriction, and if it affects the pharyngeal side, painful swallowing can occur, resulting in difficulty in chewing, eating and swallowing. In severe cases, there may be systemic symptoms such as peripheral discomfort, headache, increased body temperature, and loss of appetite. The cause of this disease is mainly the third molar because the gap is not enough to grow out, the crown is mostly covered by the gums, the gums are easy to retain food residues, the human body resistance is reduced when the onset. If wisdom tooth pericoronitis occurs in normal people, the treatment is very simple, only need to remove after anti-inflammatory, but if pregnant women suffer from this disease, the trouble can be big, serious individual pregnant women even had to terminate the pregnancy. It is not advisable to perform tooth extraction during the first and second trimesters of pregnancy. Tooth extraction in the first trimester is likely to cause miscarriage, and tooth extraction in the second trimester is likely to cause premature birth. This is mainly due to the nervousness and panic of the pregnant woman during the extraction and the painful stimulation of the anesthetic. Therefore, women who are ready to have a baby should go to a regular dental hospital for an oral examination before preparing for pregnancy, and it is best to take a digital surface tomography dental film to get a comprehensive understanding of the dental situation and listen to the oral surgeon’s opinion, the fillings, the extraction, to avoid the suffering of dental disease during pregnancy.