Hi there and thank you for your question.
It is true that there is a possibility of temporary or permanent nerve damage following the removal of a lower wisdom tooth. I usually tend to ascertain this risk with the use of an Xray and quite often a 3D CT scan if the nerve is seen to be very close.
This nerve that you refer to, supplies sensation to the lower lip and chin area on the same side of the wisdom tooth. Hence the natural concern and worry - as no body wants a numb lip !!!
Should the wisdom tooth not need to be removed, then naturally you will not have the risk of this potential nerve damage. However if there is preexisting decay of the wisdom tooth and even of the tooth adjacent to it, then it would be prudent to have this removed with a CT scan to aid pre-surgical planning with an experienced dentist or surgeon.
There are also other options by which the dentist may opt to remove the crown of the wisdom tooth alone and hence the roots will remain in-situ and thereby the nerve not damaged in anyway. This will be clearly discussed at the consultation visit and you will be able to participate in the decision making process.
Hope that this helps
Dr Samintharaj Kumar