Medicine: The Deadly Toothbrush

"A kiss without a mustache is like an egg without salt," runs an old Spanish saying. That is only one of dozens of attempts to define the psychology of the mustache. Scientists examining the ticklish subject have offered assorted explanations: mustaches are telltale signs of political conservatism or father worship, emblems of confident nonconformity, or "epigamic adornments designed to win mates, like phosphorescence in fireflies."

Astonishing Contrast. By any definition, the mustache is supposed to bespeak virility. Thus it has long been associated with that most virile of pursuits—war.* German soldiers used to grow mustaches when they found their Kraft ebbing....