All snakes can kink. However Cinni's aren't any more prone to it than normals. There are however I'm sorry to say morphs like Caramels that do have a higher tendency to present a "Kink".
A "kink" is simply a deformation in the spine. It can be very dramatic and severely hinder the animals life and well being or it can be as simple and the tip of the tail being "misaligned".
Super Cinni's can have a deformation of the size and shape of the scales on what amounts to the bridge of their nose. It gives them a wider and concave looking snout reminiscent of a duck bill.