Jim, I only suggested charging for teeth as a way of discouraging those who won't take "NO, I don't paint teeth" for an answer. I've found that folks are apt to back off if you threaten their wallet.
The thought of painting a gleaming set of choppers like the ones you did Jim, would surely lead me to a complete and total nervous breakdown.
I confess, I couldn't possibly produce as good a portrait as you did in your example. Congratulations on doing the impossible!
By the way, I remember seeing in the Peabody Museum in Salem, MA a framed artist's list of prices circa 1700's. It really was a standard practice for an artist to charge by the hand, ear, etc.
This is why so many early portraits of men had one hand hidden inside their shirt...they were too poor/cheap to pay for painting two hands. (Note that there weren't many toothy grins in those days either). Next time I'm in the neighborhood, I'll get a copy of this list and post it.