In this tutorial I had to add in teeth/gums and the tongue to the model in order to continue rigging the face. I had to readjust the teeth and tongue a little bit (using a lattice) to fit with my model correctly since my model was a different shape to the one in the video. Afterwards I made sure I updated the UV's by unfolding and laying them out again. A rig was then made for the tongue which was parented into the rest of the head after being skinned. A control was then made to control the tongue and some extra attributes were added to the lip controls to move the teeth if needed.