Lower Jaw – In the lower jaw the most important anatomical structure to be avoided is the ‘inferior dental nerve’. This nerve runs from the area behind the wisdom teeth, passes under the molars and emerges onto the skin of the face in the region where your premolar teeth are or used to be. This is why a normal dental anaesthetic produces a numb lip even when the needle was placed right at the back of the mouth. If this nerve is disturbed or damaged during the placement of dental implants it can lead to temporary or even permanent numbness of the lip on the affected side. This is a rare but important complication.