Darth Malack

[Fargazer]

"Had his mouth taken off"? How is that possible? A mouth is a hole. You'd have to like sow it up and even then the hole would still technically be there.

http://starwars.wikia.com/wiki/Darth_Malak

Specifically, there's a picture of him with his "jaw casing" removed. He got his mouth cut off by his master's lightsaber.