I recently had TADs to close my molar spaces. How long it could take, best and worst case scenario, to close the gaps?

It's difficult to answer this question without diagnostic records and clinical examination.  What I can tell you is everyone's teeth move differently.  We generally give our patients a guideline of space closure of about 1mm / month - this is not from scientific data, just what we have seen clinically.  For example, if you have 8mm of space to close, it could take somewhere around 8 months, give or take a few months either way.  The answer to this question also depends on your bite, and the biological response of your teeth and bones.  Good luck!