I would work out your loop placement before you increase the density.
You need to add the main loop around the face, starting on the the chin and encompassing the mouth, nose and eyes. The bottom part of the loop will make up the chin and the top part of the loop will create the top of the forehead. RED
The second loop you need to add is around the eyes, this is often called the raccoon mask. It should loop around both eyes and the top of it should line up with were the eye brows should go. White
Finnally you need to add a large loop around the mouth and nose area, this is so that when the character is rigged it can smile with nice smile lines. Green
I have also set up the .Blend so you can take a look at the mesh yourself. Loops.Blend
I am not implying my mesh is the best layout, there are other layouts that you may find fit your needs better. It might be worth your time to search the net for “face mesh typology”. That way you can find one that fits your needs.
Typology is one of thous things that you can fudge for a still but once your character is rigged and animated all the weird creases and bad loop positions will create folds in undesired areas during animation.