I wear Invisaligns. They costed $4000 and the orthodontist takes very detailed impressions of your teeth. They send the impressions to the company and they make all of the aligners and then send them back to the orthodontist. I wear a pair of aligners for 2 weeks and then switch to a new pair. They really are pretty invisible, though, because most people don't know I have them or even forget that I have them. They're working, too, because I can tell a difference. Regular metal braces would have cost $3200 but I am happy I went with these. They don't correct as much as the metal ones do (supposedly) but if you're just interested in straigtening teeth for cosmetic purposes I think it's definitley the best option. My sister had regular metal braces and I think I've had less pain with these and will be finished with wearing them sooner. Plus, with regular braces the orthodontist can tell you that it will take 2 years and you might actually wear them for 3 or more...with these you already have all the trays made so you know exactly how long you will wear them.