In some cases, when you have a very irregular bone
next to the extraction
site, especially very thin bone
, after an extraction, it becomes like an edge of a knife, and will cut through. It happens, and if that is in your case, the dentist or an oral surgeon, needs to round the edge of that bone , it will then heal. It usually appear on extractions of lower wisdom teeth, on the tongue side, the bone there, can be very thin.