Dear M.A.:There are some old people who sit around with their mouths hanging open. Though they may be brilliant, this expression does not send that message. Is the cause slack jaw muscles? What can a person do to counteract this? — Harriet Gill, San Diego
Oh, Harriet, that’s a bum rap. No medical folk I checked with believed today’s popular slack-jawed look is any more common among oldsters than bewildered youth. But old or young, the most likely cause is chronic mouth breathing, maybe caused by nasal obstruction or weak diaphragm or abdominal muscles. A slouched, head-forward posture can also produce that Neanderthal jaw-drop. Poorly fitting dentures might keep more seniors than juniors open-mouthed, but all in all, it’s an equal-opportunity affliction, according to my experts.