Let’s continue with our light-hearted look at science and health by answering a major question about the Christmas icon Santa Claus: What causes his dimples? Wait a minute, wait a minute. Dimples? Yes, it’s right there in the poem, “A Visit from St. Nicholas”:

His eyes—how they twinkled! his dimples, how merry!

Sometimes they’re hidden by his moustache and beard, of course. But what causes dimples?

The primary cause is actually genetic and comes from a difference in the zygomaticus major muscle, the muscle that attaches to the corner of the mouth and pulls up and back when contracted, i.e., when you smile. Some people have a double smile muscle, and others have a Y-shaped muscle; with two points of attachment on the upper portion, the extra attachment causes the dimple.

Dimples become more pronounced when you smile. There’s also another reason dimples become deeper—you carry more fat in your face. Santa’s pretty chubby, so it’s no surprise he has dimples.

One more on Saturday.

What are you prepared to do today?

Dr. Chet