Question about sliding genioplasty: should I wait until teeth are aligned to fix my weak chin?

Far more important than the technique is the skill and experience of your plastic surgeon. Choose your surgeon rather than the technique and let them explain why one technique may be better than another.  See the below link on some suggestions on finding the most qualified Plastic Surgeon for you.  Always insist on a board certified plastic surgeon.

Sliding genioplasty is an extreme surgery that I don’t recommend unless you have functional issues. To fix the cosmetic problem of a weak chin, a chin implant would give you the correction you want. You must find an expert facial plastic surgeon to help you with this. I hope this helps.

Chin surgery produces no interaction or interference with teeth orthodontics; that is one of its primary advantages, it is not orthognatic surgery.The only point is the imflammation during the postop; may interfer your dentist's work during 1-2 months; do discuss better with your dentist.