Nerve Repositioning- the lower jaw has a nerve that runs through the back part of it which supplies sensation (feeling) for the lip and the chin. This must not be damaged otherwise one might get a numb lip. Even though this nerve does not cause any deformity or drooping of the mouth it must not be damaged. Many times there is not enough bone above this nerve. Trying to place implants into a little bit of bone can be risky. It is sometimes safer to move the nerve to the side to prevent damage and to enable large, strong implants to be placed.