This logo is a combination between tooth and face. It represent a stetic and dental care
Symbol wise- this one is a fail. It looks way more forced than your other versions. And the tooth/face in this one is bordering on creepy! I don't understand the white under the neck? Try simplifying the whole symbol. Sometimes going all the way to just the bare minimum of whats needed can yield some cool results.
You had the connection with (Leon) in some of the other options, but it is not here. I do not think the face is related.
I like how you made things very simple in option 5.
Keep trying am sure you will get what you want eventually.