Why Do We Have Wisdom Teeth?

- asks Rachele Cooper, a scienceline staff member

A troublesome tooth. [CREDIT: DR.BUNN.COM]
By | Posted February 5, 2007
Posted in: Ever Wondered?, Life Science
Tags: ,

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.

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  1. 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!

    Randol, May 4, 2014 at 6:34 am
  2. 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?

    Taylor, May 19, 2014 at 7:39 pm
  3. 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.

    Kitty R, August 7, 2014 at 11:44 pm
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  6. 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

    Kaylee middlebrook, October 17, 2014 at 5:39 am
  7. 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?

    Erica, October 31, 2014 at 6:31 am
  8. I would hardly consider spoons,forks and knives to be “marvels” of modern technology

    Amanda V, November 18, 2014 at 2:00 pm
  9. 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.

    Lulu NYC, December 6, 2014 at 7:24 pm
  10. 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.

    Pierogi Chan, January 3, 2015 at 3:18 am
  11. 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 ..

    cathleen, January 13, 2015 at 11:38 pm
  12. 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?

    Reilly Cooper, January 24, 2015 at 10:57 am
  13. 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.

    Kyrstal G.R., February 7, 2015 at 9:52 am
  14. 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 :-(…..

    Jobish, February 17, 2015 at 9:32 am
  15. 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. : (

    Aaron, February 21, 2015 at 12:34 am
  16. 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.

    Maray Bee, March 17, 2015 at 10:48 am
  17. 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?

    Victoria, March 29, 2015 at 1:02 am
  18. 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

    Akilah, April 17, 2015 at 10:28 pm
  19. 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 :)))

    mc, April 28, 2015 at 1:06 am
  20. 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.

    Roxi, May 3, 2015 at 6:24 pm
  21. 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.

    Mike, June 23, 2015 at 4:07 pm
  22. 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

    Anastasia, June 23, 2015 at 4:47 pm
  23. 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 :(

    Chris, July 17, 2015 at 9:18 am
  24. 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.

    Uri, September 2, 2015 at 2:34 am
  25. 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.

    Alex, October 25, 2015 at 11:58 pm
  26. 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

    saniyah, December 6, 2015 at 12:49 pm
  27. 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

    Khalid, January 20, 2016 at 11:20 am
  28. 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

    Anonymous, January 23, 2016 at 7:21 pm
  29. I have crossed 26 but still haven’t got 3rd set of molar :(, it worries me……

    Kazi, February 6, 2016 at 10:26 am
  30. 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.

    woowood, February 21, 2016 at 12:20 am
  31. 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.

    Janna, February 24, 2016 at 3:28 am
  32. 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!

    James Carson, March 31, 2016 at 2:04 pm
  33. 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.

    Melissa, April 12, 2016 at 1:44 pm
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