Wisdom teeth are the third set of molars located at the back of the mouth. They look exactly like the first and second molars, but sometimes they can be a little smaller.
They are commonly called wisdom teeth because they are the last of the 32 permanent teeth to emerge between 17 and 25 years oldwhen you are older and wiser.
You might know it not everyone grows up all four wisdom teeth. You may also know that many people pull them. So it’s fair to ask – why do people have them?
We study teeth and can tell you that the answer has a lot to do with the distant past – and a little with the present day, too.
Stronger jaws
Just as you share many characteristics with people you are related to, humans share characteristics with their extended family – the primates. Monkeys, gorillas and chimpanzees everyone has wisdom teeth.
A few million years ago, early human ancestors had larger jaws and teeth than humans do today. For example, a species called Australopithecus afarensis, nicknamed Lucy’s species after a famous fossil specimen named Lucylived about 3 to 4 million years ago.
The jaw and teeth of one Australopithecus afarensis individually they were enough bigger and thicker from yours. They had three large molar teeth with thick enamel. The fossilized skulls of some of these very early humans also show clues strong masticatory muscles.
Dietary changes
Scientists believe that they needed stronger jaws and teeth because the foods that early human ancestors ate, such as raw meat and plantsthey were much harder to chew than the food today.
Researchers are looking at things like marks and tiny wear patterns in fossilized teeth to understand what the extinct ancestors might have eaten.
Today’s food is much softer than in the past due to many factors, among them Agriculture, cooking and pantry. Softer, easier-to-chew food means the teeth have less work to do.
As a result, modern human jaws have evolved smaller and the faces to be flatter than our extinct ancestors did, because our meals do not require the same large, sharp teeth that theirs did.
Given these changes, which occurred very slowly over millions of years, the third molars – the wisdom teeth – may not be as important now as they once were.
Wisdom teeth are missing
About 25% of people today are missing at least a wisdomite completely, meaning it never formed at all. While people occasionally don’t grow back teeth, they are much more common for wisdom teeth.
Scientists aren’t sure why this is, but it is it may have to do with genes you inherit from your parents. Some scientists have argued that the The lack of wisdom teeth is a plus for modern people with a smaller jaw. It’s definitely easier to fit fewer teeth into a smaller jaw.
Sometimes, due to lack of space, wisdom teeth can get stuck inside the jawbone and never fully emerge – or only partially emerge.
The so-called entrapped wisdom tooth occurs more often in the lower jaw than in the upper jaw. In cases where the wisdom teeth are only partially lifted, people can sometimes experience pain, tooth decay or gum inflammation, which is why they are pulled by the dentist.
But wisdom teeth usually do not need to be removed if they are fully repositioned in the mouth, properly positioned and healthy.
Dentists can examine your mouth to see if your wisdom teeth are present, or look at X-ray pictures of your jaw if those last molars haven’t yet erupted and you suspect they may be impacted.
Dentists can also advise you if any treatment – or removal – is recommended for your wisdom teeth. In the meantime, brushing at least twice a day and dental floss daily will help keep all your teeth healthy.
Ariadne LetterProfessor of Dentistry, University of Pittsburgh and Seth M. WeinbergProfessor of Oral and Craniofacial Science and Human Genetics, University of Pittsburgh
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