I had one that was slightly impacted, but didn't have any probs with it. Had the procedure done while I was sleeping. Kept icebags on my cheeks routinely and didn't even swell much. They asked me if I had any questions (after they'd started my IV) and sillly me asked if I could keep my teeth. I remember hours later when I'd come to my sense at home, my dad was like, "Um, here are your teeth that you wanted...?"
Now sis on the other hand...
Hers had impacted her sinus cavities even. SHe could drink something and then blow her nose and it would come out!
She had to take some heavy antibiotics to keep it from getting infected and could only eat certain foods for a few days. Best I can remember though, it still only took her less than a week to get back to normal, and that was an extreme case.