Numbness After 3 Weeks After Wisdom Teeth Extraction, What Should I do?

Numbness can happen after teeth extraction. The numbness could be due to a slight trauma to the nerve, such as crushing or stretching. It could be due to partial or complete cut of the nerve. The trauma to the nerve usually heals but the healing time differs according to the cause of trauma. Your treating doctor would be the best resource as he/she would not the circumstances of the surgery. Good luck. 

Numbness following the extraction of a lower wisdom tooth is a well known risk of that type of surgery. It very often can take anywhere from a few weeks to a few months to return to normal. Occasionally, it never returns to normal. It all has to do with the trauma to your mandibular nerve which lies in your jaw very close to the roots of the wisdom tooth. If that nerve is totally severed, the feeling may never return to your jaw. More often than not, however, there might have been a slight "bruising" of the nerve or simply extreme inflamation, in which case the feeling usually does return. Only time will tell. Be patient.