When a tooth turns rotten, it's impossible to think about anything else. And a rotten tooth is very much on my mind right now. A week ago, while munching a heel of Italian bread, my fourth and final mandibular molar (those bottom grinders in the back) produced a tiny twinge. I tried to convince myself the tooth was fine. Just because its three brothers had, under similar circumstances, cracked to their roots and gotten infected didn't mean this one would.

Alas, the molar's crankiness soon progressed to rage. Now, one week of putrefaction later, my jawbone has become a symphony of suffering.

Half out of my mind, I trek to see David Iurlano, D.M.D., a Pittsburgh-area dentist whom I view in a spiritual light. On three prior occasions he spelunked his way deep into my jaw, extracting demon molars and extricating me from hell on earth.

"Another one, Jim?" he asks. I nod, eyes watering.

Most patients who lose teeth can blame tooth decay or gum disease. In my case, a predisposition to cracks appears to be the culprit. I am an identical twin, and both my brother, John, and I have lived our 55 years almost entirely free of cavities and gingivitis. Despite this, over the past decade we have both lost — in identical order — the same three molars. (Our wisdom teeth got pulled in college.) It became a race to see which of us would lose his last bottom grinder first. Unfortunately, I've just won.

Over the next hour, Iurlano arm-wrestles the fiend with an assortment of tools, his forearm muscles and veins bulging from effort. At last, the villain surrenders to its fate.

"The socket area is going to be pretty sore for a couple of days," Iurlano says. "But after that, you should start feeling a lot better."

His prediction proves correct — at least physically. As pain recedes, disquiet courses in. With each previous loss, I had managed to chew by shifting to an ever-dwindling number of bottom grinding surfaces. But the difference between having one mandibular molar and having zero is profound. Nuts, raw vegetables, hard pretzels: Will I ever eat them again? I envision myself hamster-chomping pabulum and veggies boiled to mush.

Suddenly I feel very old. What's more, after the swelling abates, I look old. With no back teeth in my lower jaw to brace my jowls, I resemble Edvard Munch's famous screamer.