IK Animation Symbols vs Shapes

I’m working on an IK based character animation, and I have a question about the different IK “types”.

I’ve started by creating a charater, created using symbols to represent the various body parts, which works great, and I’ve created a shape based armature as well to handle the mouth because the shape based animation works perfectly for animating it.

Is there a way to “attach” the shape armature to the symbol armature to that the mouth will move with the head during animation? It is difficult to keep the mouth armature aligned with the face manually, and the bones don’t “stick” when I drag them from the symbol armature to the shape armature.