We usually can manage to chew food without any painful bites to our cheeks or tongue.
Once in awhile something goes wrong and it’s painful. I took a chunk out of my cheek earlier today. Ouch It had been a few months since I bit myself.
How are humans able to chomp down with 32 teeth without inflicting major damage on themselves? Somehow we manage to keep our tongue and cheeks out of the way.
Or, if it’s easier, what goes wrong when we do bite ourselves? Why did that cheek get in the way?
One data point. A common warning is to never drink hot liquids or eat if the dentist numbed part of your mouth. Those that ignore that warning are in for a painful surprise after regaining full sensation in their mouth. I learned that lesson the hard way one time in my teens. I didn’t think a hamburger required all that much chewing.
WAG maybe we are subconsciously reacting to pressure and move our tongue or cheek just in time? We’re always just missing contact with our teeth as we chew. Just my WAG
I don’t have an answer (sounds like the OP was approaching one at the end of his/her post) – just wanted to say it’s a neat question. It would make for a good Radiolab segment.
Well I’d certainly like to know how that bit of cheek manages to get caught by that particular bit of tooth edge so conveniently left so very sharpened by a previous dentist’s excavations…
Scans of a mouth chewing food would be very informative. It would be interesting to see how we flex our cheeks to avoid biting them.
I protect my tongue by keeping it planted firmly down inside my bottom teeth. That’s the safest place for it. I’d assume most people do the same thing.
Trying to talk and chew can result in a bitten tongue. Yet another reason to eat first and talk later.
Right. I’ll bet the toungue’s sensory pathways (in tongue, brain, and in between) for both propioception (an organ knowing where it is at any given time) and surface stimulation are especially dense and well-developed. Remember that “homunculus,” the funny little guy with the huge tongue and big hands? That was meant to illustrate how the brain “sees” the body.
The tongue has it doubly difficult. The cheeks just kind of form a net to keep food from falling out of your mouth; they don’t tend to get bitten unless you deliberately use your cheek muscles to force them inward. The tongue, OTOH, has to actively push food out from the middle of the mouth into the gap between your upper/lower teeth without getting itself into the danger zone. It’s a bit like a factory worker positioning a workpiece in a drop forge without tongs, hoping he goes home at the end of his shift with all of his fingers.
Because animals (including humans) that bit there own tongues while eating didn’t evolve to pass on this defective behavior onto their young. Any animal that bit it’s own tongue a lot and didn’t adapt it’s behavior not to do so probably got numerous infections in childhood and died before having offspring.
I’m sitting here eating roasted pumpkin seeds and I realized that I do nothing like this. The tip of my tongue is pressed firmly into the hollow into the roof of my mouth while I chew a seed with my molars.
Doing it your way felt really awkward, like trying to write with my left hand. I also almost bit my tongue after only two seeds.
Right. Why are humans able to do it? Because every single species for millennia that led to our being here is/was able to do it. Wherever the first successful mouth developed, it was successful because it came with enough muscle control (or the right shape, or whatever) to avoid the creature eating itself with its own mouth.
That explains why we have the ability to do it, but it doesn’t explain how we are able do it. It’s like explaining walking as a survival-of-the-fittest evolutionary adaptation without discussing the roles of equilibrioception, kinesthetics, or proprioception in making it possible.
The question remains: how are we able to so reliably refrain from biting our cheeks and tongues? Is there an automatic brain circuit that pulls the tongue back just as the teeth come down? Is it a learned response that develops as teeth come in, sort of like the learned responses for riding a bike (do toddlers bite themselves more often than adults)? Does it rely on the tongue’s dense enervation to accurately sense where the teeth are and stay just out of reach?
I will speculate that the ability to not bite one’s own tongue/cheeks while chewing relies on a lot of sensory input from the nerves in those areas. The best evidence if this is that children with congenital insensitivity to pain damage their cheeks and tongue a lot, sometimes to the point of biting their tongue off.
Missed the edit window:
EDIT: thinking about it a bit more, especially the second part of the question (what goes wrong when we DO bite the inside of our mouth), I would guess that with a numb mouth your jaw/tongue/etc may move in a very abnormal way, such as walking when your foot or leg is asleep. Very clumsily, no control. It’s interesting that even if I expressly try to bite the inside of my cheek on purpose, it’s pretty difficult. But I’ve certainly done it on occasion by accident, and yes it’s kind of an interesting question what exactly happens then.
This is a good indication that is a learned skill. I’m sure we aren’t born just randomly chomping down, but we and other mammals will quickly develop the coordination required to avoid biting ourselves through negative reinforcement as long as we can feel when it happens.
As a data point, after I had a molar removed, I bit my tongue and cheek a lot more, probably due to the fact that my internal mouth map no longer matched reality. Similarly, I had a growing lump of scar tissue removed from the inside of my cheek - it started with one unintentional nip, and was becoming a major problem because as the scar tissue got more prominent, it got bit more and grew more.
It is also worth noting that while mouth and tongue control in humans is developing, we don’t have a lot of teeth, so errors of judgement at that stage are not disastrous. And we learn fast.
Natural selection. The earlier models that bit themselves more frequently were angry and bitter and in a foul mood, and unattractive breeding stock. Their oral structure was dictated by a gene that died out.
Montaigne wrote about his table manners that he was so aggressively voracious at dinner, that he often injured himself biting his fingers and hands.
Don’t forget the utility of practice and repetition.
Babies generally start eating solid food before they get a full set of teeth. The first teeth are almost always the central incisors, so biting the cheek is an impossibility. The pattern of growththereafter puts the molars last. This is a two-and-half year process. They have many thousands - millions? - of mouth movements in which to learn the proper way to convey food into their throats. They probably do make some mistakes, but it’s likely that amount of experience gets chewing down to an automatic routine at a very early age.
The advent of wisdom teeth may create some cheek biting due to unfamiliarity, but they don’t appear until well into adulthood so the accommodation period is generally short.
I had surgery to remove a benign growth on my tongue and discovered how much it’s utilized in eating. The first meal after surgery was easy to eat, but the second included meat balls. I wound up having to manually place the meatballs between my teeth.
I suspect that learning to move your cheeks out is a learned skill such as walking.
Tongue position probably changes as we eat. I noticed mine was pushed down inside my bottom teeth. There’s no way of knowing what happens when I’m not thinking about it.
Chewing and walking seem to be learned behaviors that we don’t consciously think about. You may stumble if you think about your walking stride too much.
Biting my cheek is my most common mistake. Happens a few times a year. Biting my tongue is much less common. Maybe once a year. That’s just my own experience.
Eating lunch here, I see that I instinctively pull my tongue down and back when I open my jaws, then push my tongue forward as I close. With each bite, the tip of my tongue touches my front teeth, but only after they’re far enough closed that I have no risk of biting my tongue. When I start to open my mouth, I pull the tongue down and back again.
Since we have three people here doing it in entirely different ways, that definitely supports the idea that infants are each independently figuring this problem out for themselves.
