I am still practicing for the portraiture demonstration I must do for my art club next week. This is my niece. She is really beautiful and has gorgeous teeth.
Teeth!! Egad!! It is really best to choose a pose without teeth, but some people are natural only with a big smile and all their teeth showing, so learning a way to paint that is necessary. I chose to paint very carefully the outline of the teeth but not the individual teeth themselves. The outline expresses her identity without making a "portrait of teeth." I also tried to remember that the teeth are on a curve and I must model them just as if I were painting any round object such as an egg. At the last minute I remembered the little highlight along the upper lip. That removed the odd look that made it seem her lip was caught and sticking to her teeth.
Really, it is best to chose a pose without teeth.