Since it's so close to the wisdom teeth, it can be accidentally cut with a scalpel or with a high speed bur during tooth
sectioning during a wisdom tooth extraction
The patient has a TOTALLY numb tongue if the lingual nerve is cut in two. I know this will sound strange but it's a good sign that only half of your tongue is numb. If there's tingling, burning or pain in the tongue, part of the lingual nerve is working and not completely cut.