thanks vim, jsprogg and arran, much appreciated
not quite finished the teeth and upper jaw but here's some quick 'progress so far' shots.
Nearly onto basic muscle masses.
https://www.flash-fx.net/3D/images/polarbear/skull6a.gif
https://www.flash-fx.net/3D/images/polarbear/skull6b.jpg
https://www.flash-fx.net/3D/images/polarbear/skull6c.jpg