HMMMM.... That looks like it was lathed which can be done without a spline. Spline modeling is great especially for doing human faces and body parts or anything that requires many smoothe curves. That is one the short-comings many poser users have that I deal with. They use their poser characters and neglet many of the more difficult points in modelling like building their own human/animal models. Many out there do build models for poser but the bulk of the people that I interact with are dumb-founded when it comes to splines, nurbs, and patches