The representation of this product has been based on physical behavior of the bones. SSS shaders have been used to achieve this effect. This can cause very slow render times so I recommend in case of animations deactivate the SSS of the skull object (turn the factor to 0), but keep the SSS on the teeth.

The cuts that appear in the images of this file have been made using the Boolean modifier using a cube object (fig.1). You can make these intersections in the position you want and thus be able to contemplate the internal parts. Then apply to skull this modifier and hidde the cube (fig.2).

                                fig.1

                             fig.2