Q. Dear Dr Andrew, could you please advise regarding invisalign. I have been to 2 dentists regarding that. the first dentist showed me cases where upper and lower teeth when together showed a huge gap (where you can put several pensils in there) and how imvisalign completely corrected that to straight teeth. My teeth have a very minor gap. another dentist said that invisalign will straighten the teeth only by 60%. but the first dentist showed 100% straightening. which one is true? 100% or 60%?,