I needed to have my 1 tooth crossbite fixed - not only for aesthetic reasons but it was affecting the health of the rest of my teeth. I had a traumatic bite which caused neighboring teeth to the crossbite to have enamel chipped off. My dentist who is also one of the best orthodontists in the country and a close friend of mine recommended Invisalign as the best solution for me. I expected my first aligners to be a bit painful but they were just a bit tight and overall no problem to wear. My invisalign is literally invisible - just makes my teeth look shiny :) Nobody noticed although I have been bragging to all my friends about them :) I am only in the beginning of the treatment and will let you know how it goes after the expected 10 months. My dentist said it is common to need some minor adjustments at the end of the 10 months - which is fine with me. Updated on 14 Jul 2009: I forgot to mention I am 25 years old and currently am at the end of my 1st week of treatment. So far I am very happy with the process. I am having my buttons put in tomorrow (3 on the bottom and 1 on the top) and also will have my teeth filed. I am a bit nervous about the teeth filing and will keep you updated about how that goes. In my case it is really necessary because there is just not enough space in my mouth for my teeth as is and my dentist said they wll only do some minor filing. The filing will mostly be on my bottom teeth which are very crowded.   Updated on 16 Jul 2009: So today I got my buttons in 1 on top and 3 on bottom. My dentist made them lighter color than my teeth because I just started whitening them - this way they will match my teeth when they become whiter too. Visually the buttons are not obvious at all, at first they felt weird but a few hours later my mouth got used to them and are no problem at all. The only pain in the butt with the buttons is the getting the aligners off and on - buttons make it sooo difficult especially getting off part. But I'm sure I will get used to that too. Today they also filed my teeth. I had dreaded having my teeth filed since I first considered starting Invisalign - but to be honest it wasn't bad at all. They dont just file down all your teeth - but little by little every few weeks or months - I can barely tell they did anything at all. It was painfree and was not drastic - so I'm pretty happy about that. I also just started with 10% concentrated Nite White gel which I will keep for only a few hours a day in my aligners. I have sensitive teeth in general so am curious wether my teeth will start hurting from this whitening gel. I will update how my whitening goes as well. Below are some pictures from my second week now with buttons and aligners on. I tried to get the camera as close as possible to capture the aligners and buttons - otherwise they are invisible. Nobody has noticed yet and my speech is perfect (on the very first day my "t"-s and "p"s sounded funky). All the photos I have uploaded so far are with aligners on. Updated on 6 Oct 2009: I am currently on aligner # 7. The changes are small, incremental but steady. Additionally i realize how important it is to wear the aligners all the time. Sometimes i will take them off ot have coffee in the morning and forget to put them back on for up to 2 hrs after that and when trying to put them back on i can feel they are tighter than before. This happens because the teeth try to move back in their original crooket position whenever there is nothing holding them in the right position. So now that I am one third in the way, it is much easier to deal with invisalign and am used to the way they feel when you change aligners (they are tight the first few days when you get a new aligner because thats when the teeth move the most). Additionally my dental hygiene is awesome - I got used to flossing every single night (which was a very radical change in my perspective haha :) )   Updated on 18 Feb 2010: Aligner# 17 and the process is going great! I get compliments on my smile all the time now - everyone notices the difference and now im proudly grinning wide :) We're not done yet - one of my upper canine teeth is stubborn and not moving according to schedule - but thats ok my orthodontist said we will need to focus on that tooth once im done with my 20 aligners. Also things are not lining up perfect yet - but there is time for that too because after all - im not finished with all my aligners yet. Overall I am an extremely happy customer  :) Updated on 10 Mar 2016: I really recommend it my teeth are just perfect! Sorry for the pixelated pic but my smile radiates with happiness as you can see!