When I was in high school, I had orthodontic treatment for about 2 years. I extracted 2 at the top and 2 at the bottom for a total of 4 extractions. I am satisfied with the results, but sometimes my jaw hurts while eating. There are more cases where the device falls off while eating.. I live in Bundang, but the dentist is in Songpa, so it was very inconvenient to go back and forth.