Mind Bomb 35: How does your wisdom tooth relate to your brain

Mind Bomb 35: How does your wisdom tooth relate to your brain

Recently, I got my x-ray done to see how many wisdom tooth I have to remove. My scan revealed 2 wisdom tooth.

See that wisdom tooth over the right? That's an impacted wisdom tooth and it is caused by the restriction of space in the jaw, making it grow sideways.

And that got me wondering, why would nature allow wisdom tooth to grow when there is not enough space for it? Why is it called a wisdom tooth, does it have anything to do with our brain?

Apparently, YES! But first...

Why do we have wisdom teeth?

Photo Credit:Jim Lord

Photo Credit:Jim Lord

The answer to the question lies in the lifestyle of our ancestors. The caveman's diet consisted of raw meat, roots and other vegetation such as nuts and berries.

In a time where meat was eaten fresh from the carcass, without fire to cook it or knifes to cut it, the cavemen needed large strong jaws and all 32 of their teeth to get the job done.

Having all three molars meant that they would be able to chew and consume such a tough diet. Not to mention the fact that there weren't any dentists around, so having all their teeth available meant that some would still be left when others eventually decayed and wore out.

Smaller jaws = bigger brain

As we discovered cooking and our lifestyle changed through the ages, we begin to evolve.

Photo Credit: Richard Wrangham

Photo Credit: Richard Wrangham

Our jaws started to shrink. But it seems our wisdom teeth haven't gotten the memo yet as they continued to grow despite the lack of space, thus causing it to erupt abnormally and grow sideways, causing complications.

The shrinkage of our jaw might relate to our dietary change. Our food is usually cut to "bite-sized" proportions and meat is cooked to tender.

Not only that, but our food are more readily available. Our daily diet can now be controlled and adjusted and we don't have to spend energy hunting for food. This is far from the days of the caveman, whose menu depends on how they catch.

All these easy-to-eat sources of protein resulted in a startling outcome, one that makes us irrevocably human - the increased size of our brain.

The book "Catching Fire: How Cooking Made Us Human" elaborates this simple hypothesis - with less energy needed forage, chew and digest food, humans have developed a smaller, more efficient digestive tract, freeing up more energy for brain development.

Photo Credit: Waldir

Photo Credit: Waldir

The weakening and shrinking of our jaw also freed up space for our brain. And so that how our wisdom tooth relates to our brain. But there's more...

Why is it called a wisdom tooth?

Our wisdom tooth only starts to appear after reaching a certain age (between 17 to 25). As one usually becomes wiser with age, the growth of his third molars is seen as a sign of wisdom. Thus, the wisdom tooth was named.

It may have lost it's necessity, but at least for now, it is curiously tucked on the edges of our jaws, reminding us of our distant past.

Why do some of my friends don't have them?

Photo Credit: AFS

Photo Credit: AFS

Some of my other friends have four, some have none. Some of my friends have large enough jaws to accommodate their wisdom teeth, others do not.

For my case, I have got two wisdom tooth, my right wisdom tooth is impacted and is highly recommended to be removed. However, my left wisdom tooth is well accommodated.

Such differences aren't just random, there are even patterns in populations. Nearly 100% of Mexican Indians have wisdom teeth, while only 0.2% in Bantu speakers from Angola. In fact, these teeth do not appear in the jaws of 35% of the world population. The difference lies in a single gene - PAX9.

So if you don't have wisdom teeth to begin with, that could mean you are part of that 35% who are slightly more evolved than the rest. But if you have them and your jaw is large enough to accommodate them, your primal instincts are still very much alive inside you, and that is something to brag about.

Photo Credit: James McElveen 

Photo Credit: James McElveen 

For the rest of us, like me, we just got to bare with the cost and the pain of removing them - Thank god for aesthetics!