Hello everybody, I've had my invisalign since Aug. 2011 and I was seeing results in as little as months. I recommend them to everybody I know. It's very practical and easy. If you have an important affair you can take them off for that event and then pop them in. You have to be disiplined though because you HAVE to wear them in order for them to work. It's a bit uncomfortable the first 2 days of new aliners. You have to change them every 2 weeks. So far, I am extremely satisfied. My treatment is for 24 months.