To be honest, I wouldn't know what it meant except that the scar was somewhere on the face near the jaw or mouth.
But I can't imagine a scenario where I was reading that and I gave it a second thought. In other words, I would just read past it. It sounds fine to the ear, and if the precise location of the scar mattered I would figure that it would become clear later.
Prose need not always tell us exactly where that scar was in order to read well. And I accept my lesser vocabulary skills when reading an author that surpasses my reading level.