Since having my braces removed, my teeth have shifted. Can Invisalign fix this?

I am currently wearing braces. Can I make the switch to Invisalign?

Will I need to wear a retainer after treatment to prevent my teeth from moving again?

Are there restrictions as to what I can eat while in treatment?

Will wearing Invisalign aligners affect my speech?

Can I just wear the aligners while I sleep?

How often must I wear my aligners?

How often must I see my Invisalign doctor?

How long will treatment take?

Will Invisalign treatment be painful?