Step 1  In a well-lit area tip the patients's head back.
Step 4  By pushing back and down towards the tongue, remove the key. The next hole for insertion of the key should now be visible.
Step 3  Pushing the key towards the back of the mouth, you will notice the fender will rotate and the new hole will appear. The rotation stops when the key meets the back of the expander.
Step 2  Place the key in the hole until it is firmly in place.