About a month ago I was eating brunch at a restaurant with a bunch of relatives and bit my fork.

You’ve probably done something similar at least a couple of times in your life. It’s hard to know why it happens, but every now and then the automatic coordination of hand and chewing muscles goes awry for a split second and ouch! You feel stupid, but you bit down way too hard on that shiny metal object that was in the way.

The masseter (one of the muscles powering the jaw) is one of the most powerful muscles in the human body, depending on how you define “most powerful”:

The strongest muscle based on its weight is the masseter. With all muscles of the jaw working together it can close the teeth with a force as great as 55 pounds (25 kilograms) on the incisors or 200 pounds (90.7 kilograms) on the molars.

In that restaurant a month ago, I immediately knew I’d bitten on that fork really, really hard, harder than I’d ever bitten on a fork (or a spoon, for that matter, but isn’t it usually a fork?) before. I was with a group of people and I didn’t even cry out (too embarrassed), but I figured it would get better in a day or two.

Or three or four or five. It didn’t. The affected tooth (lower incisor on the left) continued to hurt, although I couldn’t see any chip or crack in it. I was away from home—on the west coast—for a few weeks, so I would have had to have found a dentist in a strange place in order to have it looked at, and fortunately after a week or so it started getting better. A month later, it was about 85% healed.

That was last Friday. I was having dinner at another restaurant (maybe I should stay away from restaurants??) with a friend. I wasn’t thinking about that tooth at all, which by that time only ached a bit when I brushed it or when I bit hard into something like an apple. What was I eating for dinner? Ramen. Soup with noodles, soft soft noodles.

And yet all of a sudden, apropos of nothing, while I was chewing on those soft soft noodles I felt my lower incisor on the left grind alarmingly on its lifelong companion and previous friend, my upper left incisor. What on earth?

I figured it was a fluke and started to eat my next spoonful of noodle soup. But it happened again. And again and again and again, which managed to not only be tremendously annoying, but to stir up the pain in the lower tooth.

It being Friday night (naturally!), I couldn’t race off to the dentist right then and there. I figured the grinding would go away soon, of course. But it didn’t. For approximately the next two days, every time I ate, those two teeth ground on each other terribly every third chew or so. It didn’t matter how careful I was or how slowly and mindfully I tried to chew; it happened over and over.

Until suddenly—almost as suddenly as it had begun—it stopped. I made an appointment with the dentist anyway, and went there this afternoon to find out what might be happening. After x-raying it, he told me that I’d traumatized the tooth (I already knew that, of course) so hard that the ligament that held it place showed up on the x-ray, a sign that it was still inflamed.

But why had it suddenly moved on Friday, and why did it just as suddenly go back again? Apparently, injuries to teeth can cause them to extrude, or move upwards out of the socket. Sometimes the extrusion is pretty obvious and immediate, and requires intervention. In my case it was a delayed and very slight and temporary reaction, just enough to cause the grinding but not enough to last long or need any treatment.

In other words, my tooth decided to leap up a bit in my jaw and then it got beaten down again.

[NOTE: Here’s an article that appeared in 1911 in Scientific American on the power of the human jaw. It contains this interesting piece of information:

…[C]andies that are quite hard offer much less danger to the teeth than gum drops, which ordinarily are mashed out of shape at from twenty to thirty pounds. If part of the gum drop became wedged between the cusps of the teeth, it was found that frequently it could not be completely crushed with a pressure of less than 250 pounds. Sticks of licorice proved particularly dangerous in this way. But the most remarkable discovery was that even bread might cause the breaking of a cusp. To quote Dr. Black, “With my personal observation, more teeth that seem sufficiently strong have been broken with bread crusts, and not very hard crusts either, than with any other one thing.”

Food for thought.]