percentage is nothing. Always it can be you ..
Any surgery close to nerves = risk of permanent nerve damage. Avoid surgery if the nerves are so important for you
Moreover if you think the nerves are so important for you, you may get irreversible mental problem when the s**t happen
Make a test.
Take a sticky tape and put it on your face on the area supported by a particular nerve
Wear it at least whole day. Do not remove it.
This is how can it be after surgery for the rest of your life. Never better
If you can accept OK undergo surgery
if you think you you would become crazy with such feeling THEN FORGET SURGERY,
This is the best test IMO. Sticky tape on the skin really gives quite similar sensation of not fully recovered sensory nerve.
Dulled feeling and something is pulling the skin. In that way most people feel loss of feeling.
You can get even parasthesia
AND THE MOST IMPORTANT!! ALWAYS DIVIDE BY 2 WHAT SURGEON TELLS YOU.
By the way, take a look here:
http://jawsurgeryforums.com/index.php?topic=6064.msg49573#msg49573