I first noticed it on Alice Ann, LAHS Class of ’59, a slight vertical groove visible on the tip of her nose, a normal, even appealing, characteristic that differentiates one nose from another. Wiggling my finger on the end of my own nose, I could feel a similar groove under the skin.
Many years ago, my sister and her husband adopted an infant boy of unknown parents that showed more and more psychological problems as he matured. His face had no philtrum, that vertical depression in the middle of our upper lip. This omission is a common physical characteristic of fetal alcohol syndrome, the root of his psychological problems, but no one knew it back then.
A recent YouTube animation from the BBC, http://youtube/wFY_KPFS3LA, shows how the human face forms on an embryo by three pieces coming together at the center and fusing during the second and third month of development. Anything impeding the fusion during that brief window of opportunity results in a cleft palate or a missing philtrum. When everything goes right, we are left with a philtrum and that vertical dent in the tip of our nose. Groves around the middle of our face are good.