I started orthodontic treatment in my early 20s, and I think it finished after about 3-4 years. I don't remember the exact cost of the orthodontic treatment, but I remember it being around 4-4.5 million won! I had a gap between my front teeth, and the upper and lower teeth were very asymmetrical. Maybe because I did it as an adult, the treatment period was long, but my teeth became evenly aligned, so I'm very satisfied!!!!
Right now, I have a wire attached to the inner side of my gums, and I'm continuing to use a clear retainer. I wear it once every 2-3 days before sleeping and take it out the next morning, and even doing it like this, the retention is going well.