Normally i use 3d max to make the basic head model and then export it as an .obj file to the zbrush …i creat the ears seperatly but when i connect the two ears to my head model what is the best way…i use union but it made no sense…plezzzzzz help 
I have very vague memories of 3DS max, and as far as I remember then Union is a Boolean operation … NEVER use Booleans, it fu*** up your objects topology.
What you need to do is to combine the two objects (head and ear) so it is one object using the Attach commands… When the two objects are attached as one object, then weld the vertices.
I hope this can help you - or someone who actually use Max will correct me 
thanx dear :D:D:D:D