Here is another video with kids smiling. As in the previous example, tag when you see a toothy smile.

Here’s another one. Same as the last two, tag when you see a toothy smile.

Discussion for this practice exercise:

What you will start to see is that the more comfortable you get with this, the more critical you are of your criteria. You may decide to define your criteria more precisely. For example:

• I want to see the top and bottom teeth
• I just want the lips separated
• I want to see only the top teeth