Life Science

Why Do We Have Wisdom Teeth?

- asks Rachele Cooper, a scienceline staff member

February 5, 2007
A troublesome tooth. [CREDIT: DR.BUNN.COM]
A troublesome tooth. [CREDIT: DR.BUNN.COM]

Not just a year ago my wisdom was tucked tightly away in my mouth, just below the surface of my gums, bothering no one. And then, last fall, it decided to emerge in the shape of three large, impacted teeth that had to come out. As I lay under the dental surgeon’s tools over the holidays, slowly coming out of my anesthesia, I wondered to myself: where did these teeth come from?

Anthropologists believe wisdom teeth, or the third set of molars, were the evolutionary answer to our ancestor’s early diet of coarse, rough food – like leaves, roots, nuts and meats – which required more chewing power and resulted in excessive wear of the teeth. The modern diet with its softer foods, along with marvels of modern technologies such as forks, spoons and knives, has made the need for wisdom teeth nonexistent. As a result, evolutionary biologists now classify wisdom teeth as vestigial organs, or body parts that have become functionless due to evolution.

Why do wisdom teeth wait to erupt long after the tooth fairy has stopped leaving change under your pillow? Tooth development, from baby primary teeth to permanent teeth, takes place in an organized fashion, over a course of years, with the first molar erupting around the age of six and the second molar erupting around the age of 12. Wisdom teeth, which begin forming around your tenth birthday, are the last set of molars on the tooth-development timeline, so they usually don’t erupt until you are between the ages of 17 and 25. Because this is the age that people are said to become wiser, the set of third molars has been nicknamed “wisdom teeth.”

Some people never get wisdom teeth, but for those who do, the number may be anywhere from one to four – and, on very rare occasions, more than four, according to a study published in the Journal of the Canadian Dental Association. Scientific literature has yet to be able to explain why the number of teeth per individual varies, but for those who do get these extraneous, or supernumerary, teeth, it can lead to all sorts of problems.

Because human jaws have become smaller throughout evolutionary history, when wisdom teeth form they often become impacted, or blocked, by the other teeth around them. Also, if the tooth partially erupts, food can get trapped in the gum tissue surrounding it, which can lead to bacteria growth and, possibly, a serious infection.

Wisdom teeth that do not erupt but remain tucked away can also lead to oral problems, such as crowding or displacement of permanent teeth. On very rare occasions, a cyst (fluid filled sac) can form in the soft tissue surrounding the impacted wisdom tooth. These cysts can lead to bone destruction, jaw expansion, or damage to the surrounding teeth. Even more uncommonly, tumors can develop in the cysts, which can lead to the jaw spontaneously breaking if the tumor or cyst grows too much.

There are patients that develop wisdom teeth that function just as well as every other tooth in the mouth, and as a result they do not need to go under the knife. But no one can predict when third molar complications will occur, and the American Association of Oral and Maxillofacial Surgeons estimates that about 85 percent of wisdom teeth will eventually need to be removed.

If you do have wisdom teeth that you are thinking of having taken out, the association strongly recommends that patients remove wisdom teeth when they are young adults, in order to “prevent future problems and to ensure optimal healing.” People who have oral surgery after the age of 35 have higher risks for complications, harder surgeries, and longer healing times than those who get them removed in their late teens or early 20’s. The best time to get those suckers out is when the roots are about two-thirds formed, which is generally between the ages of 15 to 18. Though I was…well, a lady never tells her age, but suffice it to say that for me, a weeks long lack of locution and a diet of soup and applesauce was worth no longer having pain in my jaw and food in my teeth.

About the Author



Randol says:

I see people love speaking or in this case typing while opioids(Tylenol 3,vicodin,percocet).I had my wisdom teeth out and I waited too long, about 30 yrs old. I recommend removing them sooner than later!

Taylor says:

The information in this article is simply incorrect. We are meant to have space for 32 teeth in our jaws. It is only recently in our history that our jaws have become too small for all 32 teeth, due to our nutrient-deficient industrialized diet. When the mother does not eat the necessary amount of minerals, the bones in the face of her baby will become malformed. Please see the work of Dr. Weston A. Price, who studied healthy populations that ate traditional diets without refined grains/sugars or pasteurized products. The people he studied all had 32 teeth and the incidents of cavities were very low. He documented his research in the book On Nutrition and Physical Degeneration. Think about it – at what point in evolutionary history did it become necessary for humans to surgically extract wisdom teeth? Wouldn’t the potential for infection and death have caused this trait to be selected out a long time ago, if they were really unnecessary?

Kitty R says:

Speculation leads some to think wisdom teeth are ” leftovers” from some evolutionary change. There are many people who never had to have their wisdom teeth removed, or their appendix removed. There is always a purpose for whatever is a natural part of our bodies, even if we can remove it and do without it. I had my spleen removed many years ago and I have been fine ever since. That doesn’t mean that organ is left over from ” evolution”, it just means that I have lived without it and did well anyway. Please stop attributing everything to evolution, which didn’t even happen to begin with.

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Kaylee middlebrook says:

I have two supernumary wisdom teeth, aka six wisdom teeth. I just got them removed today and I have some advise, don’t eat solid food until your oral surgeon/ dentist says you can, my friend ripped out all of her stitches eating pizza and Doritos the day after her wisdom teeth were extracted

Erica says:

I am 52 and my second wisdom tooth has just come through. I only have 2 wisdom teeth on lower jaw and thought there was not enough room for this recent one to come through. It was extremely painful and I didn’t realise it had come through until I realised there was no longer a gap. Is this unusual to get wisdom teeth at such a late age?

Amanda V says:

I would hardly consider spoons,forks and knives to be “marvels” of modern technology

Lulu NYC says:

When I was 25, I went to a dentist who encouraged me to just yank out all my wisdom teeth. Thinking he had some kind of fetish, I decided not to listen. All my teeth shifted as a result to accomodate the wisdom teeth. Now at 29, I just had one wisdom tooth extracted this morning with local anesthesia. I feel great! Havent even taken any of my pain medication. The bad news is because of not listening to the first dentist and my teeth shifting, I am now in need of braces. I am getting them in this month but it ended up costing me a pretty penny. I should have just extracted them all when I had the chance.

Pierogi Chan says:

I was 18 when I got mine, and I wasn’t put to sleep or put on laughing gas.
My mouth was numbed and I had all four teeth removed.
The first wasn’t that bad but by the 4th tooth, I was groaning and a few tears rolled down my eyes. My cheeks were swollen for almost two weeks, but i was able to eat after 3 days, even if I started to eat the next day with a lot of struggle.
It was painful for over a week though, but I’m glad I got it over with.

cathleen says:

Hi am 26 . am in to much discomfort . my cheeks hurt n jaw my inner back teeth I feel pressure some times can’t eat at all .. I got all four wisdom teeth n they r growing in side ways laying on top my jaw bone . n am getting them removed in I. Days am vary scared. . my jaw feels funny ATM .. Its creeping me out ..

Reilly Cooper says:

I’m 16 years old and I’m supposed to have all four of my wisdom teeth removed soon. But I’m concerned because I’ve never had any problems with cavities infact I’ve never had one until my wisdom teeth started to come in. I’ve been brushing and flossing as I normally do, so I’m confused at to why I’ve been dark spots on my teeth. Does anyone know if they can cause other teeth to become weaker?

Kyrstal G.R. says:

I got my so called wisdom teeth at the age of 17, was all a-ok had to get one removed because they had to make room for a root canal. The rest never hurt untill now though, I’m now 20 and I’m in so much pain I can’t eat or sleep. It’s an agonizing pain. Seriously why are they even called wisdom teeth, they should be named torture teeth. Now I gotta make an appointment as soon as they can get me in and get the last three yanked out. This is just torture. I hate dentists. I’m terrified of going to them. Bad experience.

Jobish says:

I’m getting my wisdom teeth now(22). It’s very paining and I’m getting small cysts near by teeth. It’s very painful. Very bad experience :-(…..

Aaron says:

Never get your wisdom teeth pulled (unless they’re impacted). You’re gonna need them for bridgework when you get older, if you’re one of the unlucky people who were born with poor teeth… Take my word for it. : (

Maray Bee says:

Wisdom teeth will come in the age of 17 to 19 and its give a lot of pain to mouth because I have suffering this pain but after reading this post I recover this pain very soon.

Victoria says:

I just wanted to ask if anyone has ever experienced facial changes as the result of extraction? I got mine removed 5 years ago at 19 and since then have noticed my face has gotten narrower..I’ve done a lot of research online and apparently your facial height/width is reduced 2-4mm for every tooth extracted. To say I’m despondent would be putting it lightly..and consequently strongly leaning towards getting dental implants to regenerate the bone/restore my natural face. While I still think I’m pretty there is no question my face was fuller and prettier before and at my age I just can’t accept that. Has anyone else experienced this?

Akilah says:

I’m getting one in now at 21! :( hopefully I didn’t do anything wrong so far…I’ve been soaking my mouth with peroxide every night to avoid an infection. I don’t want a cyst forming from the fluid of the peroxide. Grrrrr

mc says:

My dentist was deceived twice by the almost perfect way my only surviving wisdom tooth integrated. What happened is: one of my molars was extracted, teeth migrated frontwise (as they always do) and the gap left by my regular missing molar was nicely filled in by my wisdom molar. Guess what: I am happy I didn’t extract it, so my advise is: evaluate your situation by yourself, do not follow blindly this new “extract them all” fashion . I was told they would come out fray and decayed, and believe me, it is not true. As my other regular molars give in, I wish I still had my other wisdom teeth. To make the balance tilt even more in this direction: my grandmother’s dentist was able to give her a dental prosthesis because in her seventies she still had her wisdom molars :)))

Roxi says:

At 24 and having already had 3 wisdom teeth through with only mild toothache, my 4th one is making it’s appearance. The agony is ridiculous, I’m gonna get over my long standing phobia of the dentist and get the thing out…I just can’t deal with the extreme jaw and tooth ache anymore.

Mike says:

I am a 55 year old male and to my last three dentists dismay, I have four functioning wisdom teeth. A dentist in Wyoming thought they should be pulled when I was still in my teens but could not give me a good reason to have them pulled, so I didn’t. My dentist in Nebraska wanted to do a study on functioning full sets of wisdom teeth in the US…. he had never seen a jaw that had four wisdom teeth that looked like they belonged. And my last dentist in Utah was replaced because I got tired of hearing about them. I have heard about all of the horror stories and two of my three boys had their wisdom teeth removed because of problems, the third has never had them and believes it is because he is more evolved. I believe that medicine is not the answer to all things and that cookie cutter medical solutions should not be applied. This is to the dismay of my oldest son who is a DR. My appendix was bad and I had it removed, do not remove parts of you until you have to they are hard to replace once they are gone.

Anastasia says:

Some of these “its unnecessary to pull healthy teeth” comments are ridiculous. The concept is nice. “Oh my wisdom teeth grew in straight so obviously surgery is just a way to make more money”
But the thing you people clearly fail to grasp is that your teeth are not everyones teeth
Not everyone gets a painless experience and gets to keep healthy teeth
My wisdoms were fine for a while and I refused to have them removed
Now im 22 and I want those pests gone
They pushed up a little more over night and ive been in pain for five days now on top of having a fever for 2 days
I cant eat, it hurts to swallow it hurts to talk it hurts to just sit there
You need a reason to justify surgery when your teeth are healthy? I will gladly trade my jaw for yours
Dont fill peoples heads with “dentists just want more money” youre going to delude people into living a life of agony.
3 weeks of agony until my appointment and I zealously await for the removal of these unneeded problems

Chris says:

I got two wisdom teeth that gave me grief for a few months in my 20’s when they were breaking through, but 13 years later they’re just 2 big extra molars that don’t give me any trouble anymore. I feel sorry for the people who had to go through surgery and ended up bleeding for over a week :(

Uri says:

I’m 35 and just had ll 4 of my wisdom teeth removed. One of the biggest mistakes of my life. They were fully erupted and functional. I had sleep apnea for a long time and the nocturnal reflux did a lot of damage to them but that was addressed and the cavities filled and stable for over a decade. I have an open bite and those were the only ones that touched so I needed them to eat. I was planning jaw surgery to fix my bite and naturally, my surgeon told me I had to get them removed before jaw surgery. So I did and now I don’t have a bite. I’ll be eating from a blender for the next year thanks to that stupid mistake. And I loved those teeth! I can’t get them back now :( My mouth feels so small, I wouldn’t know how to chew even if I had a normal bite. Frustrated, I asked my surgeon why I “needed” to get them removed and his response was “they just cause problems”. Apparently they didn’t need to be removed for jaw surgery after all, he just decided to take advantage of the opportunity under false pretense. My gum pockets were always good back there, 2-3mm. I take very good care of my teeth. It’s totally uncool for dental professionals to presume they know what’s better for patients. It’s my risk to take – not yours! So when it’s not necessary, say you recommend it and why and give me the choice. Don’t tell me I have to in order to get another procedure when I really don’t.

Alex says:

2 of my wisdom teeth are halfway grown in, there was minor discomfort when they first came in, but a week or so later no pain. Idk if I got lucky, or if there’s more pain to come, but my advice, just wait for them to grow a little after emerging.

saniyah says:

hi I’m 14 and my wisdom teeth are starting to grow this yesterday I wasn’t not in a lot of pain but today it hurts so bad I don’t know what to do

Khalid says:

I have 32 and even though some food get stuck in between,infection happened once and the dentist told me to just clean up, as removing them might have some consequences, but food stuck means they help chewing a lot, I grew up in north africa by the way, all natural, all organic foods and a very good diet so far :D

Anonymous says:

My wisdom teeth started to grow when I am 13 now,my gum is swollen and I think my wisdom teeth is a little red,I can’t even have a proper sleep! Plz give me some advice to reduce the pain

Kazi says:

I have crossed 26 but still haven’t got 3rd set of molar :(, it worries me……

woowood says:

I still have my wisdom teeth, and nothing bordering me. I doubt that it will need to be removed. Wisdom teeth make my all other teeth strong.

Janna says:

I’m 27 and my 3rd molars are growing in and it’s pushing my teeth, so I will need braces. Also, it’s painful and is giving me a horrible headache. Should have gotten them out earlier, but I didn’t have insurance back then.

James Carson says:

I’ve just had a wisdom tooth removed, I’m 48
years old. I was expecting serious complications,
but to my surprise (apart from a traumatic 1.5 hours
in the dentist chair) I feel relatively little pain where
the tooth once was, actually I’ve more pain in my
cheek which was unavoidably damaged during the
process. My last wisdom tooth (4/4) broke through
when I was 35 years old!

Melissa says:

I am 43 years old and have not had my wisdom teeth removed and I have never had any issues. My teeth are all straight and I have never needed braces. I think we are all different, and some people might need them removed, and some don’t. I believe sometimes dentists just want to take them out just to make some money! I have been told several times that I should get them removed just encase?? But I have no dental issues at all.

Bill says:

I am 49 and had one of my wisdom teeth removed this week. All 4 were fine up until recently when one of them seemed to be getting excessive pressure when bbiting, as if it had decided to grow a little bit more. Dentist said he had his removed as soon as they erupted as he knew his would cause problems later on. Evolution is determined by laws of physics so I guess these teeth gave some of my ancestors an advantage in terms of survival. Perhaps enabling them to chew food when the earlier teeth had decayed or when our diet became coarser.

Nathalia says:

I had a 2nd-molar removed from my right lower jaw when I was 19. Few months later, my 3rd molar grew in place with my 2nd molar. So is it possible to remove the 2nd-molar instead to give way for the wisdom tooth?

Lynn says:

I am 30 years of age and have just had 2 wisdom teeth grow through at the top back and 1 this last week jus pierce my gum at the bottom, no idea why I am getting them so late.. I keep reading posts remove earlier but wouldn’t be possible for me since I didn’t have them until recently.

I’m wondering if there is any science to support the “wisdom teeth make other teeth stronger” comment. Perhaps just like stem cells in the umbilical cord, enamel and other things from wisdom teeth can be used in later life for dental work?….one woman mentioned it helped with bridge work…can wisdom teeth be used as implants instead of using bone from cadavers as is the case now?

Ro says:


Things evolve, that doesn’t mean that things weren’t created.

Creation and evolution are a part of life’s design.

The reason why you are removing these vestigal things is for the same reason we clip our toenails shave or wax our body and so on and so forth.

Chill out.

Cohen says:

I got my first wisdom tooth at the age of 16. Im now 17 and have just noticed that i can actually see my wisdom tooth coming out of my gum, because of this, i am having extreme pains when i eat and drink (basically anything that touches my wisdom tooth). Any ideas how i could minimise the pain?

Xander says:

I have one showing on my left side. Everyone says it hurts but its more of a slight annoyance. I don’t want to get it removed though because they’re going to tell me I need braces…I have really “bad” teeth and have all my life so I find braces pointless now and dentists money hungry.

Dan says:

At 47 years I still have my wisdom teeth. Denist said my mouth was big enough to accomodate them.Never had crowding. I do concentrate on them when I brush.

Troy says:

My mouth actually has room for wisdom teeth and they are all good except for one. One tooth is trying to come in where a molar’s spot. So now it’s stuck because there’s already a tooth there. If they take the molar out, they don’t know if the wisdom tooth will come in right. And the wisdom tooth it too high up to get.

NYC says:

Just getting my wisdom teeth out now and I’m over 55. In my 20s, while in the military, a dentist informed me that my wisdom teeth were “healthy and well positioned” so extraction was “unnecessary.” And she was right, but that was then. Fast forward to 2017 and they’re still well positioned–but not so healthy. In fact, two have substantially decayed underneath the gum line where I couldn’t see, or reach with floss, and they had to come out. Unfortunately, decay is infection and it spreads and the decay spread to both molars in front of those wisdom teeth so all four must come out, two on top and two on the bottom. Two have already come out with no pain–an excellent oral surgeon is a must, ladies and gentlemen, but as a result of those surgeries, I plan to have the remaining wisdom teeth extracted to ensure no more stealth decaying to my remaining molars.

Lesson learned: I should’ve had them removed years ago for zero cost to both my pocket and my molars.

Arlia says:

Two of my wisdom teeth are fine. One just erupted and is just sitting at the back of my mouth, no problem. But the other two started growing in horizontally, so I had to get them removed. So I guess it really just depends on if your wisdom teeth are causing any problems. I had splitting migraines for weeks because of the horizontally impacted teeth. Also, the extraction pain is worse than I could’ve imagined–worse then when I first got my braces. So if any are causing a problem, try to remove all the problematic teeth all at once if possible.

Dita says:

Hallo, I have all four groves out when I was 20. I lost all of my sixth teet. Gues what my wisdom teeth replaced my sixth and no trouble at all. We , who have no luck with good quality of teeth really need wisdom teeth fir suport in old age. Just think first before you take them out for no good reason, you may need them one day. Good luck and be happy to grow and wise with wisdom teeth. No fear.

Akumpesi David says:

My wisdom teeth starts to grow at age 25.I am not feeling much pain as to most people. But my problem is will there be any risk in my later live? Say 10 years to come? I really need an advice. I do not also have money to go for surgery.

Ambrossol says:

Very good information about the wisdom teeth. This article helps me to understand the wisdom teeth age, as well as the problems related to wisdom teeth.

Thanks for sharing information.

Emma says:

It’s hard to go to dentists, but consider this: until 1950’s, there was no Novocaine. And now we have Lidocaine, so almost no one has to worry about adverse reactions! We get to have ALL our dental work done while we’re numb, or pretty close. We’re luckier than ALL generations before us, and ANYONE from the past would die for our “pain-LESS” privilege. Yes, it hurts! Some of us have bad experiences, worse than most, and I really sympathize! But I’m glad for you, especially, because not one of us would rather do it without modern dentistry and dentists! Would you, now ;) ? Your dentist is your best friend. Give them a kind thank you – they get treated like bad guys, but they really do us a huge service. Be grateful for them, and for modern painkillers!

Mike M says:

There still seems to be no attempt to explain why wisdom teeth erupt so late in life. It seems to contradict the theory that our ancestors needed wisdom teeth to help cope with their diet, which was high in plant material. If our ancestors could manage without wisdom teeth until the age of 17 or 20, then surely they could manage with them at all.

Susan says:

I am 60 – have all my wisdom teeth and they fit perfectly in my mouth. Why have unnecessary surgery if you don’t need it?

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