What is the Purpose of Wisdom Teeth?
When it comes to the human body some things just seem so random. Take wisdom teeth, for example, those late-blooming third molars that humans, frankly, no longer require the services of. Some people may not get any wisdom teeth while others may have one, two, three or all four – one in each quadrant of the mouth. Heck, there are even those who will have more than four wisdom teeth – these extra teeth are called supernumerary teeth.
Some people will have their wisdom teeth come in simply fine while others will have impacted wisdom teeth that need to be removed. Scholars think that evolutionary changes in humans’ diet, from raw, rougher foods to softer, smoother foods has prompted a need for less chewing power and making the third set of molars unnecessary.
“We have teeth that were adapted for eating a very different diet than the one we eat today, at least in Western societies,” said Debbie Guatelli-Steinberg, professor of anthropology at The Ohio State University who wrote the book “What Teeth Reveal About Human Evolution”.
The fact that we can live fine without our wisdom teeth puts them in the category of vestigial organs.
Understanding Vestigial Organs in Humans
Wisdom teeth are far from alone in the human body when it comes to parts that are no longer needed or not used as they once were. Vestigial organs are parts of the human body (they also occur in animals and in plants) that no longer have a clear function.
What makes a vestigial organ?
- No apparent function and appears to be a residual part from an ancestor.
- Can become detrimental to the body but in most cases are harmless.
- Takes a long time to be phased out in the body.
Much like appendix and tonsils, wisdom teeth may need to be removed from the body to prevent invention, disease, or other illnesses.
Vestigial organs in humans include:
- Coccyx or tailbone
- External ear
- Palmaris longus muscle in foreman (absent in 15 percent of the population)
- Plica semilunaris or third eyelid
- Wisdom tooth
The Language of Wisdom Teeth
Part of the uniqueness of wisdom teeth extends not only to their timing but to a language used to describe their arrival and problems. Wisdom teeth start developing around the age of 10 but are the last set of teeth to fully arrive in the mouth, usually between the ages of 17 and 21, with a wider range between ages 13 to 25.
The fact that these third molars arrive when we are not younger but have (hopefully!) gained more knowledge or wisdom is how they became informally known as “wisdom teeth”.
When they finally arrive, dentists use the term “erupted” and when they are prevented from fully erupting, typically due to space limitations in the mouth, they are called “impacted”.
Impacted Wisdom Teeth: An Age-Old Problem
While we know that Aristotle (384-322 B.C.) waxed poetically about wisdom teeth and the pain they could cause, researchers have discovered the issue dates back a long time before the Greeks.
For his part, Aristotle said in The History of Animals: “The last teeth to come in man are molars called 'wisdom-teeth', which come at the age of twenty years, in the case of both sexes. Cases have been known in women upwards of eighty years old where at the very close of life the wisdom-teeth have come up, causing great pain in their coming; and cases have been known of the like phenomenon in men too. This happens, when it does happen, in the case of people where the wisdom-teeth have not come up in early years.”
Aristotle was not observing a new phenomenon it appears as scientists have found the earliest recorded case of impacted wisdom teeth belonging to “Magdalenian Girl”, a 13,000-to-15,000-year-old skeleton found in France in 1911.
For years, the remains were thought to be that of a girl, but recent technology has put the age of the skeleton at 25 to 35 years old. Examination of new high-quality digital X-rays revealed that the wisdom teeth were, in fact, impacted, and had thus failed to erupt at the normal time.
"Finding impacted wisdom teeth 15,000 years ago indicates that the human diet might have already changed, some would say 'deteriorated,' earlier than previously thought," said Robert D. Martin, Field Museum provost and primatologist.
Human Diet Leads to More Impacted Wisdom Teeth
While “Magdalenian Girl” gives us a clue that impaction of wisdom teeth has been around for eons, Guatelli-Steinberg argues in her book that for 99 percent of human evolutionary history our ancestors were eating food that was gathered or hunted, not processed. She says that third molar impaction is now 10 times more common since the Industrial Revolution, and its impact on our diets with processed and often sugary, softer foods. “Soft diets do not stimulate jaw growth, and teeth, especially our third molars (wisdom teeth), become impacted, she said.
Research has shown that earlier Paleolithic humans had larger jaws, and thus more room for a third set of molars, than contemporary humans. “This suggests that as human populations transitioned from a hunter-gatherer lifestyle to an agricultural one, mandibular shape changed accordingly,” concluded a National Institute of Health study.
Impaction of wisdom teeth can bring a host of issues including inflammation and infection in the surrounding gum tissue. The American Association of Oral and Maxillofacial Surgeons estimates that about 85 percent of wisdom teeth will eventually need to be removed.
Contact Northwest Oral Maxillofacial Surgery today to find out how our team of trained surgeons can help you when your wisdom teeth need removal.