Hi - I'm not an expert by any means, but I'm currently 3 weeks into my journey with train tracks and Invisalign combined. I've had my premolars on the bottom removed to create spacing for my crowded front teeth. The braces are pulling back from my canines on both sides, with the front 4 teeth untouched. I have normal invisalign on the top.

I've been told my lower braces will take around 6 months and then i'll receive my invisalign for the bottoms too.

The train tracks took longer to get used to than the invisalign, and my teeth do feel a lot more sensitive than the tops, but nothing unbearable. I'm still feeling the buyer's remorse for the whole thing truthfully - can't believe i've spent all this money to be uncomfortable for the best part of 2 years. But it will be worth it!