Many friends in the orthodontic consultation, the doctor recommended the extraction of the third molar do not understand, in order to eliminate your doubts, now the orthodontic extraction of the third molar indications are summarized as follows: 1, although the third molar has fully erupted, but no jaw teeth, or poor contact with the jaw teeth; 2, the third molar position is not correct, partial eruption, food residue, bacterial growth, local irritation led to recurrent ulcers, often cause 3.The third molar is anteriorly inclined and obstructed, which affects the cleaning of the distal mesial surface of the second molar and aggravates the risk of caries of the second molar; 4.Patients with high angle cases and a tendency to open the anterior teeth; 5.Patients whose posterior teeth are locked or anticoronal and are intended to be orthodontically treated by interactive traction; 6.Patients who need to move the posterior teeth distally in orthodontic treatment. The two most common cases are: anterior open bite requires MEAW technique to straighten and depress the posterior teeth; Class III patients need MEAW technique to move the posterior teeth far from the center, or MIA to move the whole mandibular dentition far from the center; 7, for those who intend to perform orthognathic surgery, the third molar can be considered for extraction during surgery; 8, although there is a debate on the understanding of the third molar causing anterior crowding, some doctors still recommend the extraction of The third molar is still recommended by some doctors to prevent the recurrence of dental crowding after correction.