The mouth is a different story. When older people have fake teeth, they are to be placed into the mouth before embalming. This will keep the lips from sinking into the mouth.
If the fake teeth are not given to the embalmer, the embalmer will need to place balls of cotton into the cheeks and in front of the gums. This will push the lips out, but not out too far. Number one rules is to make sure the lips make the person have a not to sad but not to happy positioning.

