Resin heads: Chin padding?

So I'm working on aresin head currently, one that was built off a proportional armature head, mind you, and I feel the chin was too small, and so sawed out a huge dip in the resin for the jaw for your chin to fit in there. Though now,  the resin jaw has to be on the tip of your chin in order for it to function, otherwise , if placed under your chin, it kind of is pushed and hangs open.  I was thinking of extending the lower jaw downwards at an angle, something for your chin to rest comfortably, before padding that area and such. 

Just want to hear how other's articulate the chin, your opinions ,etc? 

Thanks!