A few days but check with the dentist who did the extractions. They generally like the sutures to stay in for a whole week, but sometimes it doesn't hurt for them to be a couple of days early. Always call the dentist who did the extractions though if anything out of the ordinary takes place.
Resorbable stiches come out after a few days. If they fall a day following the surgery, the gum healing can still be fine, but it's better to advise the dentist and check with him or her.