Last weekend I got a toothache. It was in a tooth I’d cracked and had crowned, victim to my teeth-grinding. Maybe it’s - misaligned, or something? I’d been sleeping with my mouthguard in. Then Sunday the side of my face swelled up a little, and a spot an inch below my right eye started throbbing like a migraine, in addition to the tooth pain.

So Monday I went to my mother’s dentist. Not the one who had put in the crown. I thought it was reasonable to get a second opinion. He took an x-ray. Well, he said. Your nerve - see that? It’s dead. It died. And see that shadow around the tooth? That’s an abscess, buddy. That’s why your face blew up. All right. He swung the x-ray apparatus back into its cabinet. Let’s get this taken care of today. You don’t want the infection spreading to your brain.

My brain? I said.

I’ll send you upstairs to my friend George. Endodontist. He’s good, board-certified.

I went upstairs and got a partial root canal. Pus from the abscess shot out of the tooth when George took off the old crown. That’s good, he said. Good sign. He told me about the science of what was going on, something about macrophages. Maggie, the dental assistant, bumped my arm and gently put her elbow on my chest, knowing to distract me by activating non-mouth neurons.

They used a lot of anesthetic, tons of it. But this is what I found out later: the abscessed pus is acidic. The acid counteracts the action of the anesthetic at the nerves. So when he cut into my gums to drain the rest of the infected fluid, I felt it. Really, really felt it. “You almost passed out there,” Maggie said.

I cried in the waiting room.