Why do we suffer from TMJ? Especially in cases where it seems to develop spontaneously without any form of major trauma like a car accident or physical violence, it seems like we ought to be able to eat and chew fine without major difficulties.
It turns out that the answer to this question might come from some of the very things that make us human: technology and talking.
These two factors have so dramatically changed our jaws from those of our primate relatives — like chimps and bonobos — and even our evolutionary ancestors that our jaws may not be suited for chewing as much anymore.
Breaking the Chewing Trap
Chewing is great. It’s a way to predigest food, which not only helps us evaluate its nutritional content (mmm . . . protein, your brain is thinking when you savor that steak), but it helps us extract more of that nutrition from our food. Birds and reptiles don’t chew. Their teeth grasp and hold prey, tear flesh off a carcass, or, at most, crunch up a beetle a few times to make sure it’s dead before it goes down the hatch.
Chewing is a mammalian trait, and it helps us get all the nutrients we need to maintain our active warm-blooded lifestyle. But it comes at a cost. Mostly, it’s time consuming. If you’ve ever driven through farm country and watched all those cows out there chewing their cud, you realize that’s what they spend most of their lives doing: chewing.
Even primates and our primitive ancestors likely spent about half of their waking hours chewing. That is, until they discovered how to process food. Processing food means a lot less chewing.
Scientists disagree about what type of processing made the big difference: some say it was cooking, while Harvard researchers recently postulated that it may have been as simple as cutting meat into chunks and pounding up tubers (like potatoes) to make them easier to digest.
They claim that adding meat and tubers to our diet and using these simple approaches to processing food may have reduced their need to chew by an average of 2.5 million chews per year, about 18% less than before. But the force demands on our jaw dropped even more: we only needed to chew 75% as hard as before.
And, later, we added cooking to our approaches, and we saw our need to chew go down even further.
The Benefits and Drawbacks of Less Chewing
When you look at the face of a chimpanzee in the zoo and compare it to your face reflected in the plexiglass, there are some definite similarities, but also some major differences. One of the biggest differences is the large snout that chimps and other primates have, the snout that is necessary to accommodate the large teeth and strong chewing muscles that primates have.
We can have a lot smaller jaw and snout because we don’t need to chew as much. And that comes with certain advantages: our mouth is smaller and more controllable for making a wider variety of precise sounds, which is what allows us to talk. Not to mention the benefit of not having to be chewing all the time. How much work would you get done if your lunch break had to be four hours long?
But nothing in life comes without tradeoff, and there’s a dark cloud to this silver lining. With weaker jaw muscles and a smaller jaw, we experience some problems, such as not having enough room for our wisdom teeth, and, yeah, being at a higher risk for TMJ.
Our smaller jaw is weaker and more susceptible to strains as well as traumatic injuries. But it’s also problematic that our temporomandibular joints are just smaller, with less room for all the muscles, tendons, cartilage, and nerves that have to run through it. Even in the absence of major trauma or strain, there’s more likelihood that something is going to get compressed or pinched if your jaw isn’t aligned quite right or gets out of balance.
If you are suffering from TMJ and you’re asking, “Why?” know that it’s a tradeoff for all those hours you didn’t spend chewing as a kid.
And know that there is a solution–you don’t have to just live with the pain. To learn how we might be able to help your TMJ in Columbia, SC, please call (803) 781-9090 today for an appointment with a TMJ dentist at Smile Columbia Dentistry.