Ordinary fixed aligner brackets are required fine ligature wire to fix the orthodontic arch wire, while self-ligature is a specific device to directly latch, the main advantages are as follows: 1, long interval between follow-up visits, generally 6-8 weeks, saving time 2, clinical operation patient ease, the doctor is also very convenient 3, friction is much smaller than ordinary brackets, the teeth move quickly, after the review of the force, the pain response is light; 4, can reduce the proportion of tooth extraction ; 5. Higher comfort level, eliminating the stimulation of oral mucosa by ligature wire 6.Oral hygiene is easy to maintain