Although Seamless3d 3 has evolved from version 2 and maintains being a general purpose modeller, this is the very first version (3.000) to be released after major changes have been made to the design, so please treat it like a prototype as it is not yet complete and there are many scenarios it can not yet deal with, however if you follow the Modelling a Human Head Step by Step Using Free Open Source Software tutorial video, which is very easy to follow, you have the certainty of being able to model a human head in your own style.
http://www.youtube.com/watch?v=Kd7HBxozJMQ