When I was in the third grade, we were learning about teeth. I remember being fascinated by their internal structure: the pulp, the dentin, the enamel. At the same time, it was like bile fascination, since I thought they were creepy little things to look at in real life. Nonetheless, I’d find myself doodling on my worksheets cross-sections of model teeth, even if we were supposed to be learning multiplication tables or about the newly elected President, Bill Clinton.
At the heart of each tooth is the pulp, a collection of nerves and blood vessels that supply the tooth with sensation and life. That’s why they scoop out the pulp when you get a root canal procedure: now your painful tooth shouldn’t feel anything at all. Now I’ve always wondered how pulpy the pulp really is: maybe squishy like an octopus? In Spanish, pulpo means octopus, so I could never get that creepy image out of my head.
Wrapped around the pulp is the dentin, which is most of the living tooth. It’s similar to bone in structure, and like living bone, you don’t want this layer exposed to the outside world. In a healthy tooth, it’s completely covered. But when we develop cavities, the dentin becomes exposed and vulnerable to bacterial attack. Worse than just causing a toothache, bacteria can spread from the cavity into other parts of the body to cause havoc, like to the brain or glands in the neck and jaw.
The enamel is probably what you’re most familiar with, the outermost and the hardest layer. It’s actually the hardest material in the human body aside from some people’s skulls. The enamel covers what could be called the head of the tooth, but is actually called the crown, the exposed tooth above the gumline. (On the other hand, the root or roots are embedded in the jaw under the gumline) Our enamel wears down over our lives and not replaced, unlike in animals like rodents, who have to keep biting crap to keep their teeth short. I suspect that at one time our enamel was replaced regularly. Just how fair would it have been to Methuselah to have to spend 900 years of his 969 year life all gummy. Gross.
Now right outside the root’s dentin, instead of enamel there is ligament tissue that holds the tooth within its socket. The tissue is called the cementum because reasons. Despite the name, there’s wiggle room for the tooth in its socket as you can tell for yourself if you bite down hard, but generally teeth fit securely.
Unless you’re in a comic or cartoon. Then your teeth go flying out with any kinda hit. And have you noticed it’s invariably molars that come out? Even if the blank space left behind is where your front teeth, the flat and blade-like incisors, should be, the character still spits out molars, your big, fat back teeth. As a kid, I imagined the characters having mouths full of only molars, and that I found creepier than all get out.
Speaking of molars, the name comes from a Latin word meaning “grind,” which is what the teeth do. Incisors are so-called because they “incise,” a Latin derived word meaning “cut,” into food when you bite. Now usually when I think of an incision I think of surgery, so I wonder why scalpels weren’t ever called incisors. Yeah, I know why… too creepy.
Speaking of increasing levels of creepiness, I’m sure you’ve seen images of cross-sections of children’s jaws. Both the upper and lower seem otherworldly and eldritch with their crammed double rows of teeth. The adult set of teeth are just forming within the bone of the jaws, while the ones sticking out already are the baby, or deciduous, teeth. Deciduous derives from a Latin word meaning “fall down”—like in deciduous trees that let their leaves “fall down” each Fall. Fortunately for our sanity, our teeth don’t pop out each October, though I imagine that would make a Halloween treat for some who enjoy… creepiness.
What do I find most creepy about teeth? How about that name gum. Now that thing is something that had me staring wide-eyed at the wall as I sat in third grade. Instead of poring over my issue of the Weekly Reader, I wondered why we would chew something called gum with teeth embedded in something called gums. For the longest time I was freaked my gums could be as weak as the Bubble Tape I loved so much. Then again, they could also be as hard as the Double Bubble pellets I for some reason also loved. No—then my gums would be dry and crumbly and… ugh…
…the childhood mental image of chewing my own gums like gum has returned to haunt me. The two gum words aren’t related, I later found out, but the damage had been done. And I thought I could handle the tooth.