Are Wisdom Teeth Becoming Obsolete?
For many of us, it may seem like our wisdom teeth didn't get the memo that our evolved jaws are lacking space. But some people never develop wisdom teeth;in fact, these teeth don't appear in about 35 percent of the population [source: Spinney]. Are we on an evolutionary track to losing them altogether?
Some experts say it's possible these teeth will eventually disappear [sources: Flam, Usbourne]. Still, there are a few unknowns in the equation. Scientists aren't sure of the role that DNA plays in creating teeth at the third molar position [source: Colf]. Third molars develop entirely after birth, the only teeth to do so. Because these teeth aren't present at birth, it may be harder for nature to select against them [source: LePage]. For wisdom teeth to form, the tissue that starts the process of tooth building has to migrate back in the mouth to interact with the back jaw tissue. If this migration doesn't happen, then no tooth will grow there.
There may also be some environmental factors at work, including disease or head trauma, that stop the tissue migration [source: Silvestri, Singh]. It could also come down to differences in how various cultures use their jaws. For example, in the 1970s, researchers tied the larger jaw that was present in Eskimo women to their tradition of chewing leather to soften it. In parts of East Asia, it's more common to find people with fewer wisdom teeth, if any [source: Vines]. If people of a culture have reached the point where they don't use a trait, they may lose it.
But some scientists are beginning work on stopping the teeth from appearing altogether, so that we might bioengineer these teeth out of existence before evolution does it for us. Because there's a window of time in which there's no third molar, it might be possible to administer a laser or a chemical agent that would prevent the tooth growth. Preliminary studies have shown some success in dogs and rats [source: Silvestri, Singh].
Wisdom tooth extraction is expensive, and recovering from the surgery is no easy feat, considering that pain, bleeding, swelling, infection and nerve injury are but a few of the complications. Still, removing wisdom teeth is recommended by many dentists to avoid the pain and periodontal disease that results from an impacted tooth. The surgery should be done during young adulthood, before the teeth attach to the jaw and become too difficult to extract.
In 2007, however, dentist Jay W. Friedman claimed in the American Journal of Public Health that at least two-thirds of wisdom tooth extractions are unnecessary [source: Friedman]. He and some other dentists argue that these teeth will come in at the proper position and cause no trouble. These dentists say that instead of simply doing preventative removals for most young people, we should only remove wisdom teeth that are impacted. Other dentists say that these teeth are still difficult to clean and should be removed.
Currently, the lack of wisdom teeth doesn't produce any great evolutionary advantage, particularly with the abundance of oral surgeons who can remove the wisdom teeth that do emerge. That makes it hard to say exactly how the trait might adapt in the future. Certainly, oral surgeons probably have their fingers crossed that these teeth continue to appear for a good long while. The rest of us will have to make do with lots of ice cream and the continuous exchange of surgery stories. Sure, those wisdom tooth lackers may claim they're more highly evolved because they don't have to go through a few days of misery, but what do they talk about at boring parties?
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