Dr. Vivek Cheba on a Long-standing Mystery of Dentistry

Dr. Vivek Cheba on a Long-standing Mystery of Dentistry

Dec 17, 2021, 2:04:46 PM Life and Styles

It is true: life was rough for early humans.

Survival was dependent on a number of factors. Fuel was important for fending off beasts and also for vanquishing them for sustenance. Hunting tools were not so advanced, so food was difficult to procure – and also to chew. Fortunately for the continuation of the species, a fourth set of molars made it more possible for cavemen to garner nourishment from raw meats and uncooked vegetables.

Similar to many mammals, humans' ancestors had four sets of three molars (or a total of 12, split evenly between the upper and lower jaws). Humans, though, uniquely experienced a period of evolution that caused the human brain to grow larger, according to Princeton University researcher Alan Mann.

Thus, the human brain has grown larger and the food has become softer, but those molars continue to grow in nearly countless human mouths.

“Fourth molars, also known as ‘wisdom teeth’ are evolutionarily unnecessary. They generally come in when people are young adults and it causes an assortment of dental issues: overcrowding of teeth, shifting of bites, impaction and even infection,” said Alberta-based orthodontist Dr. Vivek Cheba.

Wisdom teeth, despite the quaint moniker, are actually an archaic annoyance.

They prove troublesome and painful for most people – but not all.

“It is a topic that has been long discussed in the dental community: Why do some patients have wisdom teeth and others not?,” said Dr. Cheba. “It is wonderful that scientists have been looking into it.” 

Many believed for years that it was simply an evolutionary phenomenon at play – a genetic adaptation to changing circumstances. The theory was that some people were simply more evolved along the tooth spectrum.

According to oral surgeons Widner & Alford, the necessity of wisdom teeth dissipated around 400,000 years ago. Fire changed everything, softened the food and made it possible to eat without additional teeth. Also, humans learned oral hygiene, which made their teeth last longer. The late-arriving wisdom teeth no longer needed to be invited to the party, particularly as the brain became larger and the room in the jaws became tighter. Still, in general, genetics are sometimes slow to catch on.

So why are some people luckily missing one, two, three or even all four of the problematic extra molars?

Scientists have been researching and now have a theory. It is not so much a matter of being more highly genetically engineered, but rather an ancient genetic mutation that appears in higher degrees within certain ethnic groups.

Mann told Live Science that a random mutation surfaced thousands of years ago that suppressed the formation of wisdom teeth, which now explains the lack of wisdom teeth in some modern humans. 

“The oldest fossils missing third molars hail from China and are about 300,000 to 400,000 years old, suggesting the first mutation may have arisen there,” according to the article.

Mann explained that between 10-25% of Americans with European ancestry are missing at least one wisdom tooth; 11-40% of African Americans and Asian Americans are missing at least one and a whopping 45% of Inuit are missing wisdom teeth, and in fact are the population with the fewest wisdom teeth.

“The fact that we keep making these sorts of scientific discoveries and explaining the mysteries of the human body astounds me,” said Dr. Vivek Cheba.

Published by Irfan Haider

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