There's much more shape to a face.
For the chin there can be many shapes, a 'v' like shape, a 'u' like shape even a very square look.
And faces generally have more shapes to them, especially from an angle, they have numerous curves, or angles, it all depends on style and even sex.
I generally draw my females with more curves and such to their face, and my males have much more angles and slightly points.
No face is just a U shape.
It's like saying all generic humans have U shaped faces, when we all have different shapes and so on.