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Why Are Human Teeth So Messed Up? (2017) (sapiens.org)
318 points by BerislavLopac 31 days ago | hide | past | web | favorite | 220 comments

As a slight aside from the premise of the article, I was reminded of a story my friend once told me. He is a policeman, and works with the Water Police department in our town.

One day, they got a call from some dirt bikers who were riding in the mangroves beaches across the bay that they had found two skeletons partially buried in the mud. As per standard procedures, a police patrol was dispatched to investigate (which included my friend), and also as per SOP, because the area was a known ancient Aboriginal burial ground, they took an anthropologist out with them as part of the investigative team.

When they got to the site and were approaching the two semi exposed skeletons, the anthropologist said (while still a few feet away from them) "Oh, these pre date local colonial settlement and are probably over a hundred years old".

My policeman friend was curious, and asked her how she could tell even from afar that these were not more current remains, and she said "It's the teeth. There is absolutely no sign of decay caused by sugars in modern diets".

He (and I) never realised the extent of damage done to our teeth by what we eat today.

This is totally anecdotal, but we have a family friend who is an undertaker in a small town. He claims bodies today rot at a slower rate then when he started in the 50's. His theory is that its the preservatives in food.

The changes in sensing time while growing old are said to work in the other direction, so he might be on to something. :)

Also, the moisture level in the soil might have changed.

Or the funeral homes got better at selling varnished coffins instead of pine boxes.

And at selling embalming as a standard and expected part of the process. For the UK at least:

- Varnished coffins are usually very thin veneer on top of mainly particle board - the glue is as problematic as any varnish, and add pollution to cremation. US coffins are commonly steel(!) apparently. "Brass" fittings are usually plastic, and not removed before cremation as you might expect.

- Embalming is so much an expected part you're not asked, it's just done. You'd have to already know it's not required and you may ask for no embalming. In former years it was common to have the coffin at home for a few days - with no embalming. Not that long ago either.

- Mind boggling amounts of formaldehyde (and other chemicals) are used by the funeral industry.

Source: Going too far down this rabbit hole and ultimately choosing a natural green funeral for me.

Burial in a wicker coffin in a forest somewhere has always appealed more to me than all these chemicals. I want to feed worms and trees after I die, not pollute the earth even more.

Pop out anything that someone else might be able to use and chuck me in the compost bin

That's pretty much what we settled on, and for similar reasons. In time, just see forest, sometimes with flat local stone or wood plaques, without bleak rows of cemetery headstones. Far more uplifting and not even more expensive, surprisingly. Not as surprising was burial in managed woodland is a fairly common option when we looked into it, some planting a native tree in place of headstone.

Needless to say once we dug into how it's usually done, we found yet another industry that's become horribly eco unfriendly.

I have to wonder how toxic the human body is. I have read that bioamplification of pesticides and heavy metals can be a problem for fish and birds. A quick google only shows me vague possibilities when reviewing humans. Is it worse for us because we're bigger and long lived, or does processed food avoid that sort of problem?

We're an apex predator, so should receive all the amplification effects seen travelling up a food chain. Course having accumulated toxins, it depends what you do with them afterwards. Natural decomposition tends to spread it back to the bacteria, fungi and small animals at the very base of the food chain again.

Burn the body in a gas furnace for a few hours and release loads of ugly things. Including all the artificial fibres, coffin glues and plastics, and any fillings, implants etc. Mercury amalgam fillings can get to surrounding animals, even into fish off the coast. From memory something like 20% of uk atmospheric dioxins are from cremation.

If burying, the formaldehyde and other embalming chemicals leech into the ground along with any accumulated toxins in the body, and can prevent proper decomposition for decades or more. Embalming that's completely unnecessary for the timescale of most burials. Mostly those chemicals are ugly, and little studied when put in the ground in scale. Yet are studied when added in small amounts as fire retardants or glues in furniture etc. Then you have the US using steel coffins in concrete lined graves!

It's quite the ugly rabbit hole once you descend and start looking into burial and cremation.

Throw me off a boat out at sea, wrapped in canvas. I'm good.

Also appealing. The problem with it is that at some point, a canvas wrapped body is going to wash ashore somewhere and people will want to know where it came from. Victim of an accident? A murder?

Edit: maybe weigh it down. That would work. And by "it" I mean yourself, I guess.

And please, skip the shoes. People have been wigged out for years around these parts, since shoes with the foot still inside have kept washing up on shore.

I think the consensus was that it was suicides or other drowning victims, not some nefarious plot, but people get twitchy.

Viking funeral pyre for me.

This story is making round a lot. I usually file it in the urban legends folder.

I legit laughed at that. Morbid humor.

Two thoughts:

1. They really are no sugar in aboriginal societies? No fruit or carbs?

2. I know a handful of people who eat Western diets who have zero tooth decay.

Doesn’t seem like a great way to tell the age of a skull.

"Doesn’t seem like a great way to tell the age of a skull."

The confidence of people far away at a different time without any relevant knowledge to dismiss an experienced local on the ground based on flawed high-level logic never ceases to surprise.

I don't actually read his comment as dismissive or confident, but more surprised and curious. There's nothing wrong with questioning other people's statements when they don't marry up with your own opinions.

Indeed. It was more intellectual curiosity.

You called the story bullshit in another comment, that’s not what most people say when they are intellectually curious.

Since when does an anecdote provide any proof? I thought exactly the same things as your parent poster. Carbs are sugar, especially if you chew long enough. This affects teeth. Combine this with a lack of toothbrushes and a lack of fluoride and it sounds like a recipe for tooth decay.

Also, people didn’t live as long as they do now. So less chance to have your teeth rotten. Furthermore: the skeletons might have been of people in their twenties with arguably better teeth than old people.

Lots of questions that this anecdote doesn’t answer and you dismiss critique as pretentious.

It's the epitome of hacker news. Reddit also has this "armchair quarterbacking" effect, but it's significantly worse on HN, in my opinion.

A lot of the people here are knowledgeable—in specific domains. I think people forget that being an expert in one thing doesn't make you qualified to judge, understand, or discuss another domain in depth.

Case in point, the recent "tech that reduces sound by 94%" post that got upvoted here.

One of the most common instances of generalized experts weighing in on topics they're not actually experts in happens in politically-related posts here, although it usually only comes in the form of downvotes.

You can cite science and demographic facts while leaving out your own overt normative opinions, yet you will still get downvoted from both 'sides' who think they are being slighted if you don't give a clear opinion. Unfortunately this is the way scientific method-driven experts talk (and generally anyone who's into political science rather than political opinion) - but in this domain it really sets non-experts off for some reason.

The thing is, most people are taught at a young age that their political opinion matters a lot, which probably has something to do with generalized experts walking into this domain thinking they're already experts and getting quickly frustrated when they realize they're not, lashing out at the source of that frustration via downvotes.

Back in the day the responses to these kinds of topics used to be via comments, now it's almost always via drive-by downvotes. I used to bemoan the inane buzzword replies back in the forum days because they were typically boring and predictable, but they were still infinitely better than the downvote without comment that is the norm for this site (and even more common on reddit).


>> 8. The USA is primarily at "One Dollar = One Vote".

> Why Is There So Little Money In Politics

> In this paper, we argue that campaign contributions are not a form of policy-buying, but are rather a form of political participation and consumption. We summarize the data on campaign spending, and show through our descriptive statistics and our econometric analysis that individuals, not special interests, are the main source of campaign contributions. Moreover, we demonstrate that campaign giving is a normal good, dependent upon income, and campaign contributions as a percent of GDP have not risen appreciably in over 100 years – if anything, they have probably fallen. We then show that only one in four studies from the previous literature support the popular notion that contributions buy legislators’ votes. Finally, we illustrate that when one controls for unobserved constituent and legislator effects, there is little relationship between money and legislator votes. Thus, the question is not why there is so little money politics, but rather why organized interests give at all. We conclude by offering potential answers to this question


Dunno who flagged-killed it. But that's directly opposed to what I was saying....

On to your comment.


Long story short, the 30 year review and analysis states that rich people (those that pay their senators/congresscritters) get their laws passed, even when rejected by the bulk of the common person. And yet popular nonrich-popular laws are regularly dismissed without a consideration.

1$ = 1 vote. It happens at the regulatory level, the bill level, and the vote level. That's corruption no matter how you frame it.

> There's something else going on with meditation and mind, that we can't adequately explain with science at this moment.

I was with your list of truths until this.

Do you mean there is published scientific literature that fully explains the mind and the effect of meditation?

Can you point to it?

It’s because the story sounds like bullshit.

I have no doubt that you can tell the age of a skull with a close inspection of the teeth. This story was an anthropologist looking at remains from several feet away and claiming that it’s aboriginal from the lack of dental decay.

I proposed a few exceptions to that rule. Certainly not a quip about the expertise of the anthropologist, but rather the accuracy of the story.

One of the benefits of being an expert in a particular field, is that you can take small parcels of evidence and formulate an accurate picture of a situation much faster than a layman with no prior experience in that field. I don't know the anthropologist in question, but I am sure she used a series of supporting evidence that was obvious to her trained eye as well as the teeth condition.

Ask any doctor or midwife who can look at an ultrasound image and tell you the sex of the baby while you are still staring at a smudgy grey moving image. Ask any accident investigator who can estimate the speed and trajectory of the vehicles while you are still looking for the skid marks.

I personally have spent over 25 years interacting on public message boards, and I am a domain expert enough that I can pick an armchair expert who has lots of perceived theoretical knowledge, but little or no real world knowledge, but still feels the need to espouse their opinion in order to get their dopamine hit of the day - all just from a quick glance at their post.

I agree it sounds like bullshit.

However, I have listened to a talk by a lady (she consults on murdered cadavers) who can tell which season a body died in by analyzing the teeth! Apparently there is a lot there.

That I can believe, assuming a detailed analysis in a lab. But snap judging from a distance? Cavities are more common in modern populations than before, but hardly omnipresent. I do find it an amusing thought that apparently my skeleton would be assigned a more distant past simply because I am filling free. :D

It might be not that hard for someone who's literal job is examining skeletal remains.

The more likely sign is not fillings, but acid damage, which softens teeth and cause biting and grinding to wear down the surface of the teeth. You can have no fillings and still have very noticeable acid-related damage.

He most likely meant refined sugars.

Sugar is being added to most foods nowadays. The timeline of cheap refined sugar is the timeline of sugar addiction and tooth decay.


Scientists examined the remains of 52 adults who had lived between roughly 12,000 and 13,000 B.C. and were buried in the cave. An astonishing 49 of them, or 94%, had cavities, which affected more than half of the surviving teeth.

By analyzing plant remains in the cave, Humphrey's team found that residents ate lots of a particularly sweet type of acorn, which becomes soft and sticky when cooked. They also ate wild oats and legumes. Such foods can lead to serious decay,

Yes, and wild oats and legumes don’t exactly seem like the exception in ancient diets.

Plus another link in this thread claims ancient fruits have different sugars that don’t cause decay.

Are you trying to imply that refined sugars do not cause an increase in tooth decay? Or that fruit sugar is similar to refined sugars?

Any ties with the sugar lobbby famous for lobbying the US government into blackmailing the WHO in increasing the amounts “healthy” sugar in their dietary guidelines?

"Refined sugar" is sugar in fruit. It is literally the same thing. That's how we get sugar in the first place - from plants. You are dealing with glucose, fructose, and sucrose in both cases.

It’s not refined while it’s in the fruit. High content, but not refined.

Even with oranges which have very high sugar content, you cannot easily eat four oranges but you can drink their orange juice along with most of the sugar and none of the fiber.

The sugar lobby’s talking points steer the conversation toward equalizing refined and non refined sugars, and calories from refined sugars vs calories from non refined sugars.

I found this in depth lecture really enlightening


Why was this downvoted? This is correct.

> Doesn’t seem like a great way to tell the age of a skull.

Going to take a guess and say that a brief glance at the teeth is probably not the _only_ age determination method they applied before determining their course of action.

and asked her how she could tell even from afar that these were not more current remains

Right, and then after making that initial assessment, I'm going to guess they didn't just stop walking, write out and sign the incident report and pull out the radio to let the station know that they were pretty much done here and there's nothing to worry about. No, I assume they walked up to it and got a more conclusive look at the body first.

skrebbel 31 days ago [flagged]

I'm not sure I've ever seen a better example of classic HN-style "middlebrow dismissal" than this comment. I want to print it and frame it.

1. Significantly less. 2. That's great to hear.

To expand on (1.), modern cultivated fruit varieties are quite different from what wild fruits are seasonally available—for one thing, you're always competing with wild animals for a sugary, tasty snack.

Here's a somewhat fascinating article looking at both sides of this debate: https://deniseminger.com/2011/05/31/wild-and-ancient-fruit/

The conclusion to me seems to be that unless you're in the tropics, you almost certainly be eating less fruit, and the fruit you'll eat will be much more varied and seasonal. A lot of the wild fruit you eat may have specific defenses (tannins, alkaloids, etc.) that discourage you from eating too much (the fruit's job is to make you spread and excrete its seeds, after all).

Thanks for sharing this story.

Teeth are annoying. Mine are ok, but as I get older I start to notice their deterioration.

I've always felt that if there was a part of our anatomy that we should think of replacing completely with an artificial design, it's teeth. We already do so now (at great expense), but it's literally one or two teeth replaced but I'm thinking more along the lines of replacing every single one with something stronger and more efficient for it's intended purpose.

I’m a freakishly lucky bastard, to date. Also, a freak.

I have a fairly gracile jaw for a guy. A bit of a chinless wonder. I have 28 teeth. Always have, since my adult teeth came through - but I do have wisdom teeth. What I don’t have are any M1 molars. They’re just not there. Seems my maternal grandfather and my sister are the same.

I’m 35, with so-so at best oral hygiene. Never had a cavity, never had a filling, never needed orthodontics - and really weirdly neither has my grandfather - he’s 86 with a complete and unaltered set of original gnashers. A bit worn down after seven decades, but all still there and working. My mother lost all of hers in a motorbike crash decades ago so there’s no telling there.

So - while I think the idea of artificial replacements is a perfectly good one, there should perhaps be some research into pheno/genotypes such as my family’s which seems to have a useful mutation for the incredible shrinking jaw. It’s this sort of thing which could be a valid use of gene editing - it doesn’t really present any advantages other than being able to eat.

One of my sisters has perfect teeth while the 3 of us other siblings have pretty bad teeth. It's really annoying :-(

Genetics play an enormous part in dental hygiene. Some people in my father in laws side never had a cavity in their entire lives - even 85 y/o grandpa (also my 28 year old wife).

I'm 42, and in the no cavity boat. I was always a daily brusher before bed, but that was it. In my early 20's, I took 5 years off from the dentist and when I finally got an appointment, I had a small amount of tartar build up, and that was it.

I've had the same dentist for almost 15 years now and his comment to me every time he looks at my teeth is: "Boring!".

This used to be quite common. In Ireland for example back in the 1970s about 30% of the population had no natural teeth whatsoever. It used to be a common thing for young women to have all their teeth pulled and replaced with dentures before being married. It was seen as a desirable trait for en eligible bride to be.

Do you have a citation on that, I’m genuinely curious about the stats on that.

I don't know about Ireland, but I did recently look up the same statistics for the UK: https://www.gwern.net/Questions#physical-beauty You can source it to the UK national dental surveys (which wouldn't be surprising if they covered Ireland as well), for example, https://archive.org/details/np70033823/page/n1

I was genuinely thinking about this...I mean for enamel is so high maintenance and gets spoilt so easily not just germs but also acid reflux and natural decay...

This is still common. I recall the anecdote that there is one US state where one in four people have no teeth, due to getting them all pulled, though I can't find the data now.

My wife is a dentist. One of her classmates told the story of their parent's dental practice, where someone had taken their teenager in, discovered they needed some expensive dental work, and said "take out all the teeth, they're gonna fail eventually anyway".

How does a parent have the ability to say that over some teen's body..? It's horrible to me to read that people would just say that.

Having had wisdom teeth removed, a couple root canals and several cavaties, and having seen the discomfort and problems my wife and daughter’s impacted teeth have had on them, you could do much worse than just ripping them all out and replacing them with high quality manufactured teeth.

Human teeth are about as reliable as the gal bladder. Obviously it would be preferable to maintain your essence but (post)agrarian diets and lifestyles disagree.

Yes I know they're not the most reliable teeth in the world, that's not what I'm talking about. A parent saying "take out all the teeth, they're gonna fail eventually anyway"? Am I weird for thinking that sounds horrible? I can't even try to make analogies for it because whatever I think of is not as bad as that quote.

I think its horrible - its far too early to make that decision for your child. I think its something a person should make for themselves. "Expensive dental work" could mean only a few teeth impacted - the rest may be perfectly great. I see no reason to take them out.

For many children, my daughter in this case, it was an option, and was suggested. We didn't go that route but given both parents teeth and the dentist's assessment it would have been reasonable.

I think what your main concern is that such a drastic body modification should not be done in a flippant manner. I feel the same way about hormone therapy.

That dentist saw a goldmine - often times the "pull it all, implant" solution is the price anchor on the top end.

Oh heck no, you act as if implants are a simple, permanent thing. I worked at a series of offices that specialized in implants long before they were a fad and whom pioneered techniques.

The reason they sell well with old people is that the patient will be dead before the lifecycle of the implant is up.

There are SO many things that can and do go wrong placing implants, especially now that every corner dentist is using them as a profit center.

Bone loss, gum recession, rejected implants, nerve issues, poor aging of crowns in both color/quality, and a million other things make implants far from a simple solution.

A full set of implants is easily over 60k often times up near 80-100k, and a huge number of full mouth implant patients had to come back due to complications (and our offices had lower complication numbers per implant.)

If it weren't for the bone loss thats hard to get back, implant supported dentures are almost a better way to go.

Unfortunately afaik all replacements are worse than real teeth.

For some reasons one of my dentists had a booklet about the replacements in his waiting rooms. They all have issue.

My dentist would be horrified if she heard about pulling out functional teeth.

She does implants but she is aware and open about inferiority of artificial solutions and always tries to save as much of natural teeth as she can because mechanical interface between artificial thing and tissue never works as good as real stuff.

See my post a little bit up - you're totally right. I saw it from the dentist PoV and theres a lot they don't tell you - let alone that most dentists should not be let near an implant.

Don't you start losing bone mass once the teeth are out?

Only if you don’t get implants, a bridge or dentures. It’s not about the teeth per se, it’s about the pressure you exert on the bone underneath the teeth. If you can still bite hard and exert force on the underlying bone you’ll be fine.

No, only if you get implants (and they are done right.) Bone still recedes if you have a denture or bridge. Its such a common issue that dental software ships with a video to show patients this.

Here: https://www.youtube.com/watch?v=xl6skf2g4pw

Jaw bones have a different (and much more sensitive) neural configuration.

What a horrible design.


No, it was to save on future dental costs, and that was seen as desireable not... what you said. It was not atypical for it to be paid for by the parents or either bride or groom as a wedding present. The idea was that pulling all of the teeth and replacing them with dentures was inevitable, and by doing it before tons of money was spent preserving the natural teeth for some time, you’d be setting the couple up for financial success.

My father had all of his pulled (from necessity) and is having them replaced with implants. It’s a very expensive and time consuming process, involving minor preliminary surgeries. I know someone else who had this done and regretted it, several of the implants kept coming out and the replacement procedure was painful and expensive. But it can be done.

I worked at behind the scenes at a series of offices that specialized in implants and full mouth replacements. The people that love them have a lot of money and don't mind going back to the dentist frequently to fix issues. The industry keeps it hush because its such a huge profit center.

(who knew this knowledge would come up)

Which is why dental veneers [1] are so popular with the easily influenced reality-show-wannabees. If you can afford veneers you have apparently made it...

So much that some of the reality stars make it a show or as part of their contracts. [2][3]

Except they look ridiculous and many can't chew properly especially some meat afterwards...

Not sure I'd want my teeth ground down to little sticks. Nature works best as it intended, I like my teeth.

[1] https://en.wikipedia.org/wiki/Veneer_(dentistry)

[2] http://www.39harleystreet.co.uk/jodiemarsh_veneers.htm

[3] https://twitter.com/jodiemarsh/status/598229937133375489

There are different types of veneers. Most cosmetic veneers are just thin layers glued onto the tooth, and often leave most or all of the underlying tooth intact. Full veneer crowns involve grinding it down.

I have cosmetic veneers on two teeth that were intact but looked awful, and they're just a layer of porcelain laminate glued to my real tooth. The underlying tooth was polished and filed a bit, but certainly not "ground down to little sticks"; the teeth could have been left as-is and functioned fine.

I also have several full crowns, but they were down because of decay, certainly not for cosmetic purposes. That of course does not mean that you can't do full crowns for cosmetic purposes, but it's usually a last resort before implants.

If you can't chew properly on a crown you have a bad dentist. Nature really does not work best in this case for a lot of us - two of my crowns are in place because parts of the real tooth shattered into several pieces while chewing, others because the damage eventually got so severe that there was too little left to save.

The problem with veneers on a few teeth is that they don't color age as a regular tooth does so you have to keep getting that fixed.

I don't know if you'd call it a veneer, but one of my upper central incisors is a ceramic and stainless steel cap over a ground down "stick", and the real one is night and day better than the fake. The real one is slightly serrated and has a sharp edge, while the fake one is totally smooth and rounded, and slightly thicker. Essentially, it feels like the mould was made out of play-doh. I can't imagine having my whole mouth like that.

I got it when I was a child (broke the end off when I was ~10 years old) and my gums have receded somewhat since then, so now there's a gap where the base of the original tooth is visible below. I was told at the time that I'd probably need a new one once I got older for this reason, but it hasn't been a problem so I haven't gotten around to it--I'm in my mid 20s now. It's also fallen out twice (once when I sneezed and it skittered across the classroom floor), so now I have an irrational feeling sometimes when eating apples or other tough foods that it's coming loose.

Really sounds like you had a bad dentist. Whenever you do get around to having it fixed, don't let them get away with it.

Also note that dentistry tech advances very rapidly; a proper crown done now will be substantially better than a crown done a decade ago, and certainly a lot better than a mediocre one done a decade ago.

This isn't a necessity, though. It boils down to the exact technique used and the skill of the technician making your tooth. Yours just sounds like it was made badly.

I'd say no if you meant replacing teeth with dentures, which get levered away from your gums by your chewing and take away your palate sensitivity. I'd say yes if you meant implants. As far as I can tell from the two I have they're just the same as natural teeth, except they can't be moved around with braces.

The Amish commonly pull all their teeth at once and just use dentures. Though I'm not a Lancastrian Dentist, I've not heard that they experience too many issues with long term dental use. Then again, their diets differ from the US norm by a fair bit. Still, they are a sub-group that does pull their teeth unnecessarily and seems to not have too many issues.


> I've always felt that if there was a part of our anatomy that we should think of replacing completely with an artificial design, it's teeth.

I'll go with the spine, for pretty much the same reasons except more.

The spine worked pretty well until computers, as far as I understood.

Nah. You've never heard of someone having a "bad back"? That's been a common thing for centuries. You can tell because it doesn't have a fancy Greek- or Latin-derived name.

And there seems to be an understanding that "bad back" is an extremely common thing that can happen to anyone. For example, when JFK was president, many of his health issues were covered up because they wanted to project the image of a young, healthy President--except it was pretty well known that he had a bad back. In other words, in the 1960's, it was considered perfectly normal for a man in his forties to have a "bad back" for some reason or another, even during an era when chronic health conditions were stigmatized.

(It probably helped that JFK's back injury was partially caused by his heroic WWII exploits, namely swimming back and forth to rescue the crew of his sunken PT boat and sometimes towing their unconscious bodies to shore with the strap of their life vest between his teeth--thus elevating his disability to the status of a heroic war wound.)

I'm reasonably sure most "back" issues are more related to the muscles than the spine. (people /can/ have spine issues, I just don't think it's as common).

This is the principal behind 'all-on-4' dental implants. I've no idea how good they are though. I've seen a few YouTube videos but you never really know if they're paid shills nowadays.

I effectively have an "all-on-4" situation but where the 4 are my natural teeth. I have a genetic condition which caused very few of my adult teeth to grow, so the ones that did grow in nice and solid have been capped with machined gold cylinders and used as the receivers for a full denture (google "telescopic copings"), which fits perfectly on them and also acts as a retainer for those teeth. It's actually quite nice and comfortable and my teeth went from being a painful horror show to functional and trouble-free in a relatively short timeframe.

Removable dentures?

Yes, but attached much more solidly than a traditional one. They slide onto the pegs and stay put perfectly without any sort of adhesive and are actually tricky to remove due to the precision with which they snap in.

If you already are losing all your teeth due to decay and can't afford full implants, then its a good option. Beside that, avoid it at all costs. You'll have massive bone loss where you dont have implants and eventually have issues (unless you're at end of life anyway and just want a good 10 years or whatever.)

If youre already losing teeth, the more implants the better, as your bone requires that object there to not recede - and bone grafting is very expensive and hit or miss.

Take good care of your teeth, theres nothing like the real ones. If I had not worked at a huge implant office, I wouldn't believe it.

Seems better than dentures, but not as good as teeth. You're putting all that stress onto 8 points in your jaws and probably losing jaw bone in between.

A person I know got their whole mouth replaced with cubic zirconia implants in his 30s and is pretty happy about it. He just said that he screwed up his teeth very badly in his 20s somehow. I didn't ask.

I feel like I'd love to have that, but I run into the same reasoning against laser eye surgery:

My work benefits cover full dental and my contacts, but I would have to pay substantial out-of-pocket for those procedures, even if they could save the benefits plan money over time.

In practice, dental implants are more work to maintain being much more difficult to properly floss. This leads to bone absorption and receding gums.

I'm interested to know why, since I have one and haven't noticed any difficulties in flossing.

Well placed implants dont have much bone recession. On the other hand, bridges or other dental solutions where theres nothing in the bone do lead to bone loss. Poorly placed implants or crowns can lead to bone/gum loss though.

If you can get a health plan with an HSA, you can use HSA money (pre-tax) to pay for LASIK. That's what I did, and I strongly recommend it.

the main problem with prosthetics is that they end up transferring forces directly to the jawbone which then causes wear and tear on the jaw instead of the teeth. the best solution to this problem is to stop using prosthetics, and start growing vascularized dental tissues from your own stem cells. tufts is working on this, im sure lots of others are as well, and im giving them 5 years for something promising before i cave and just get veneers :D

If you haven't heard of orthotropics, it sounds a bit pseuodoscience-ey, but it attempts to solve the crooked teeth issue by enlargening the jaw rather than through braces. Thus far, I have to say that I think there's some truth to exerting a little pressure to my maxilla/mandible, and if anything I can breathe much better, which for me is a bigger win than getting straighter teeth.

Enlarging the jaw is still very much under the scope of orthodontics. Palate expanders are fairly common, and are used to expand the adolescent jaw. I had one as a kid. It absolutely works. Their are devices for lower jaw expansion as well.

The pseudoscience-y orthotropics part is where adults are told they can expand their fully developed jaws.

I had a palate expander in my youth. It did not change the forces I applied to my jaw, so it didn't solve my problem, instead they emerged and re-emerged, first in my teens, then after I stopped wearing a retainer in my 20s.

What's the basis for your eager dismissal of an alternative?

I think the real science here is Orthognathic Surgery [1].

I mean - I'm not an orthodontist or a surgeon, but once growth has stopped in the palate as a teenager or young adult I'd be skeptical of claims around bone growth or sculpting. Do you have any resources?

[1] https://en.wikipedia.org/wiki/Orthognathic_surgery

I'm 34 and have personally experienced significant changes in my face thanks to orthotropic pressure / mewing, and have the photos to prove it.

In addition, my bite has been stable without a retainer, whereas in the past I've had braces twice.

My background is I had an undiagnosed mild tongue tie that I discovered a bit over a year ago. I previously couldn’t press my tongue against the roof of my mouth, which led to a tongue thrust on swallowing, which led to an open bite, and my nasal breathing was very constrained.

I just started mewing this week.

I can't get the back of my tongue up between my molars if I have my front tongue close to my front teeth. I can like either mew my front tongue or back tongue. Any tips?

Also how long did it take you to successfully be able to unconsciously keep your back tongue up? Right now it's hard for me to do it for 10 seconds bc it's so uncomfortable

The tip of your tongue should be toward the back of your hard palate - where it rests when you form the “N” sound. From there you should be able to flatten your tongue to broaden your palate / spread your molars.

I’m not sure how long it took to hold my tongue in place, but it took me 3-6 months to see initial external results, given regular mewing + chewing hard gum (falim/mastic). The bone movement occurs in tiny increments of course, but over months the changes are clear. Keeping the mouth closed while breathing is also very important, as it’s the balance of forces between the tongue and cheeks/lips that shapes the arch. For me this wasn’t easy/comfortable prior to expanding my airway via mewing. As for discomfort, I would just keep at it for a few months and see whether your palate is opening up.

For those of us that don't know (myself included), what is "mewing"?

Not the GP, but first Google result says "Mewing is simply resting your entire tongue on the roof of your mouth until it becomes an unconscious resting position for your tongue whenever your mouth is closed", and is apparently for "correcting facial asymmetry, ill-defined jawlines, and sagging jowls."

[1] https://jawlineexercises.com/everything-you-need-to-know-abo...

Exerting pressure on your palate with your tongue, which stimulates growth in the jaw and acts on the maxilla, shifting it forward and up over time.

Exerting pressure on your palate with your tongue, which stimulates growth in the jaw and acts on the maxilla, shifting it forward and up over time.

I’d love to see some actual evidence of that, which isn’t in the form of online anecdotes and testimonials on sites dedicated to the concept, or weird-as-hell “incel” sites. Something peer reviewed, in a respected journal would be a stsrt, even if the results haven’t been replicated yet.

Because it sounds like complete nonsense, and looking at the sites discussing it only reinforces my belief that it’s crap. I’ve spent some time searching for even a scrap of what someone with a hint of skepticism would consider compelling evidence and found nothing. I did find some communities I never knew existed, and wish I could now forget. Suffice it to say that “incels” are a truly strange bunch, and gullible at that.

I'm working on writing up a personal case study, showing my own experience. Plan to publish that soon.

Of course, my experience isn't peer reviewed, but it could play a part in motivating such research. After all, if society is in denial, they will not bother studying it, will they?

Care to link to a good methodology? I've been intrigued by this but there's a lot of conflicting information out there

I would go and schedule an interview with an orthodontist instead of relying on the internet, here. "Orthrotropics" appears to be a registered trademark, which is, at the very least, a yellow flag.

A cursory search on details has broken this down to extractive / surgical vs. non-extractive / non-surgical orthodontics, the latter of which has proven to be effective before the palate and growth plates have fused -- in children.

Talk to somebody you trust with a degree in the field.

> Talk to somebody you trust with a degree in the field.

Tough ask for a lot of people! I have a distant uncle who works as a dentist in the Appalacians and does a lot of pro-bono work. My family has a tradition of taking the children on a trip to see him to ask if they really need braces. Often the answer is no.

I’d feel confident asking him this question, but I don’t think most people have someone like that.

I'm interested in mewing for the purported facial aesthetic and breathing benefits

Orthodontists are incentivized against embracing orthotropics by their current knowledge and business model. They prefer interventions they can charge for (braces, slenderizing) over practices which can be adopted without intervention. This may be why the field emerged from dentists rather than orthodontists.

“It is difficult to get a man to understand something, when his salary depends upon his not understanding it” — Upton Sinclair

> This may be why the field emerged from dentists rather than orthodontists.

Orthodontists are dentists.

but dentists aren't always orthodontists. I think OP meant those that aren't.

I'm referring to dentists who do not practice orthodontistry, and therefore do not have careers hinging on the status quo.

Yes and they call themselves functional orthodontists


I can tell you what I’ve done:

* chewing hard gum, falim/mastic, for jaw muscle development

* exerting pressure on the back of my hard palate with the tip of my tongue

* focusing on adjusting my breathing and swallowing patterns to press on the palate rather than elsewhere

Look at functional orthodontics.


Also, see myofunctional therapy.

I'm in my early 30s, and I recently had my maxilla and mandible non-surgically expanded with a combination of appliances, one called Advanced Lightwire Functional (ALF) and the other called Fixed Anterior Growth Guidance Appliance (FAGGA).

Treatments that make use of the Orthotropics philosophy or of appliances like the ALF or FAGGA are relatively new and are not mainstream. However, there are many case studies available online showing them in action and showing before/after pictures.

I don't know what kind of resources you're looking for, but this video [1] provides a quick introduction to Orthotropics.

[1]: https://www.youtube.com/watch?v=_D70VF43Evw

Aren't those basically lingual braces? Moving teeth and fixing your arch doesn't require or necessarily involve mandible changes.

From the what I understand, the FAGGA basically expands your maxilla forward. Here's a good example [1] that shows the appliance in action. The photos showing the upper jaw after FAGGA insertion match my experience.

The ALF can be applied to both the maxilla and mandible (whereas the FAGGA, I believe, is just for the maxilla), but the growth it promotes is more gradual and subtle.

I don't think either appliance shares much in common with lingual braces, functionally speaking. I'm not a doctor, but from what I understand lingual braces act primarily on the individual teeth whereas the ALF and FAGGA act primarily on the jaw bones.

[1]: https://www.robinatowndental.com/jaw-expansion-without-surge...

I recently had major orthognathic surgery, a two-step process: surgically-assisted rapid palatal expansion (SARPE), where your palate is basically "mobilized" and cracked down the midline to allow for expansion in adults, and then maxillomandibular advancement (MMA), which advances the entire jaw forward ~10mm. The braces should hopefully be coming off soon.

Obviously I did this for medical reasons - sleep apnea - but I do wonder if the so-called epidemic of sleep apnea could be related to the dietary changes described in this article.

Thanks for pointing out real science. I don't believe much bone can be sculpted or grown once someone's body is fully developed. However, let's keep in mind traditional braces work even in adults because bones remodel themselves continuously. (https://en.wikipedia.org/wiki/Bone_remodeling), (https://www.simplyortho.com.au/process-behind-orthodontics/). There's also a reason if bones aren't exposed to forces, the bones start to lose structural strength, example of osteoporosis: (https://www.ncbi.nlm.nih.gov/books/NBK45504/figure/ch2.f5/), that's a scary image. Also, bones get smaller if you lose teeth: (https://www.deardoctor.com/articles/hidden-consequences-of-l...).

I don't know how any of this stuff works, I'm not a scientist, but the dots seemed to connect based on everything I believe about our physiology, which is admittedly a little "alternative". I don't think you can do exercises and turn into brad pitt, but I'd be willing to bet that there are mechanisms and signals that our body needs in order to self correct misalignments and/or regenerate that our modern lifestyles don't provide due to our indoor sedentary lifestyles.

I'm pretty sure my orthodontist did this when I had braces. He put this metal thing in my mouth that I had to crank open with a key every night for 6 months. He said it was to widen my jaw. It was absolute torture. Not sure exactly what it was or how it worked. I was like 12 when this happened.

Yeah, that's a pallet expander, and very common in orthodontics.

There's a new dental device company working on re-shaping the dental arch called Envisium (https://www.envisium.com/) out of Harvard. Great early results.

(Full-disclosure: I'm an angel investor in them and not a dentist, so only reporting what I've heard from the dentists.)

She/he disclosed their affiliation and reasonable promotion is permitted on HN as long as it's on-topic (this clearly is).

No idea if the product works, but please don't downvote just because it's promotional. If you're an expert in the field and have a particular criticism, please consider engaging in a measured response instead of downvoting.

(I have no affiliation with `dlg` or the company in question)

I highly recommend reviewing Prices account of his studies in the field: http://gutenberg.net.au/ebooks02/0200251h.html

His conclusion was quite different: that the cause was a lack of nutrients in the modern diet.

It is difficult to point to an example from his work that would clearly rule out the theory of chewing in this article. Sugar and white flour that he pointed to are both easy to chew and low in nutrients.

However, it is hard to think of lack of chewing as the primary factor in tooth decay, and Price was focused first on decay rather than crowding. Price did note a very strong relation between decay and crowding, and in that light it is difficult to view lack of chewing as the primary force in either decay or crowding.

iirc also our self-defense body's behaviour acts automatic responses when we "miss" something, as like taking some elements or create them from other organs, if in need (our organs are also bigger than what is needed, iirc also for those "emergency" states). So if missing calcium, the first places where the organism might take it from, are the tooths -iirc-.

A dentist told me that eating too many soft foods as a kid is often the reason for crooked and weak teeth, and that parents should feed their kids tougher whole foods, like apples, meat, carrots, nuts, etc.

Definitely true for muscle and jaw bone density.

See https://news.ycombinator.com/item?id=14895121 for some interesting past discussion

What are the aesthetic consequences of having a more developed jaw from chewing tough foods as you grow? Given how sensitive people are to cosmetics when it comes to their teeth, would doing this to your child positively impact their dental outcomes at the expense of conformance with modern norms of physical attractiveness, given trends like how having a small face is seen as attractive in Asia, or soft jawlines for women?

I pose this since it is likely many people would worry about aesthetics more than actual dental health, and also because the social consequences of being/not being conventionally attractive can have significant impact on people's lives as well, so answering this sort of stuff is probably necessary for actual behavior change.

There is surgery in Asia to shave the jawbones to achieve a slimmer face, so I'd expect that this kind of information would lead to an increase of giving soft foods to children in order for them to have the slim face that matches Asian beauty aesthetics. After all, orthodontics are much less expensive and painful than jawbone reduction surgery...

Example surgery site: https://www.vippskorea.com/face/facial-contouring-surgery/ja...

People also care about healthy straight teeth and a nice smile, so it's not like you're getting nothing.

Isn't an alternative explanation just that well-aligned jaws and spaced teeth are selected for via both (A) natural selection, esp. in predator species (well-aligned jaw = more efficient prey capture, chewing, defense) and (B) sexual selection as a holdover result of the first? As in, if ancestors relied heavily on their jaws and, behaviourally, a selective preference for well-aligned jaws and teeth helped favor offspring with the same, that selective behavior itself would be selected for -- and could perhaps persist even after "well-aligned jaws" were no longer a deciding factor in objective fitness?

So now there's significantly less actual natural selective pressure on well-aligned jaws / teeth in human populations, meaning phenotypic variability in human jaw / teeth is simply the result of genetic drift in a very large population. The holdover, of course, being there's a market for and industry around striving for perfect jaws and smiles in Hollywood because we have a behavioural (but no longer naturally selective) predisposition towards that signal of health and fitness.

... that's always sort of been my mental model of orthodontia as an industry, at least.

I think a stronger argument, along similar lines, would be to observe that the human skull underwent pretty drastic architectural changes in the last 200K years because of the rapid growth in size of the brain cavity. And, since the importance of teeth fell behind the importance of intelligence, not enough selective pressure existed to "fix" the teeth given the other radical skull changes.

In addition, let’s not forget the invention of cooked food. Soft cooked food no longer requires a massive jaw with jaw muscle attached to the top of the skull. Furthermore, the higher sugar content of the (post)agrarian diet creates a healthy environment for bacteria.

“Catching Fire: How Cooking Made us Human” has a lot to say on this subject.

Yep, this can mechanistically explain why the phenotypic variability exists, for sure.

The article addresses that with this: https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.1330620...

Within one generation, the palate size decreased. So that can't be explained by natual selection. Well, unless small jaws killed a huge portion of the population before modern times.

IIRC the orthotropics explanation for this is because we have much easier to chew foods, we chew much less and have poor tongue posture, leading to skinnier inter-molar width (IMW) and jawbones that are more down and in as opposed to up and out

I'd love to read it, but it's not Open Access and I'm not a member of any academic institution. Do you have a copy of the paper?

Edit: It's not that small jaws killed anybody, the hypothesis would be that in a pre-industrialized society sexual selective (behavioural) mechanisms favoured well-aligned jaws / teeth but with the rise of globalization stronger selective mechanisms superseded them. This would be mostly due to rapid real living standard + wealth accumulation gains more strongly correlated with other behaviours.

There hasn't been nearly enough time for changes in selective pressure to develop through the population. Orthodontics as we know it was invented in the mid-18th century, and it wasn't affordable until the late 19th century. That's like, four or five generations to the present with access to medical tooth alignment.

I'm not sure what the point you're making is, can you clarify?

My point is orthodontia has a large market because, outside of actual pain and health symptoms associated with malocclusion, we have a predisposition towards well-aligned jaws and teeth.

I'm not making any assessment of the effects of orthodontia on long-term selective biases in human populations.

... but also, four or five generations is not insignificant. Evolution is just a change in allele frequency in a population over time, and five generations is more than enough time to objectively measure a change in frequency with such a large population sample. (I think the better argument would be that that the number of people that have had access to medical tooth alignment is a statistically insignificant fraction of the global population.)

One can also interpret it as that, once human learnt to use fire, cooked food made jaws and teeth less important, so people with bigger brain would reproduce more, no matter how their teeth look like.

There's also cultural difference in the aesthetics of teeth, for example, Japanese culture considers yaeba as cute.

Couple of evolutionary pressures that would make sense to me:

1) Human ancestors didn’t live as long, giving them less time for teeth to get misaligned in a terrible way.

2) Animals will tend to lose teeth for various reasons, so some extra teeth (including eg. wisdom teeth that appear during the prime of life) are probably useful spares more often than not. Not enough teeth was probably a more likely cause of death than too many.

Both of my parents had well-aligned jaws with teeth suited to them. Unfortunately for my elder brother and myself, we had our father's teeth in our mother's jaws. Crowding ensued, not helped by the fact that both of us have a couple of senility teeth (my neologism for our fifth molars).

My dentist told me the reason I never needed braces, but all my friends did was from wearing a mouth guard from all the ice hockey we played growing up. They aren't perfectly straight, but except for 2 teeth, very close to it. Every dentist I ever had was like, "Did you ever have braces?"

Misaligned teeth are not the worst problem IMHO. The fact teeth of most of the humans decay in less than a lifetime and this is considered normal feels much more weird to me.

My dentists, whose service I'm very happy with, are telling me misaligned teeth are much more prone to decay than the straight ones.

Reasons being: certain parts of the dental periphery are more vulnerable since they are supposed to be covered by gums or neighboring teeth.

My dentists keep saying that our teeth are highly specialized in every meaning of the word, and every deviation from the beaten path is heavily penalized with decay and a number of other conditions.


The average human lifetime has more than doubled in the past few hundred years.

But average is a useless statistic since many people who survived childhood lived to a similar age as today.

Only if you eat a modern diet. You can't blame our teeth for being ill prepared to handle coca cola.

The fact that we grow one set of bones, lose them, and then grow another set has always been weird for me to think about.

Well, both sets actually start growing before birth, so your timeline is a bit off. The primary teeth start to come in after half a year or so after a child is born. The permanent teeth continue to develop until they absorb the roots of the primary teeth beginning around 6-7 years old, causing them to fall out and making room for the new teeth.

I think the argument of orthotropics[0], bad tongue posture, is much more convincing.

[0] https://www.youtube.com/watch?v=tO8O2y1jxtU

This article seems to be part of the recent wave of content about orthotropics/mewing. I'm not sure why it seems to have picked up so much recently.

You’re not kidding, and even a little research into this reveals it to be on the same level as dry needling and homeopathy. I think my favorite “evidence” in favor are people taking pictures when they’re preteens, and then showing how their facial structure changed with mewing. It’s not the normal course of puberty guys, it’s magic!

I can easily see why this became mainstream, because it’s easy to do, and a sucker is born every minute. I am however, surprised to see this bunk here. Although, I’ve noticed that on health topics this forum is at its worst. Endless testimonials about vitamin D, magnesium, LSD, FSD diets and more seem paradoxically popular here, and I’m unsure why that is. Maybe the California connection?

Orthotropics and mewing was widely discussed on incel communities and now that the prominence of these communities has grown, the topic is trickling to the mainstream.

Why would they be popular with incels?

Incels generally hate women and the progress made in Western society. Part of holding women in subjugation is painting them as superficial, and one good way to do that is to convince everyone that male attractiveness is based on a very specific facial feature as if a single dimension of the face can make up for more serious personality flaws.

Why is it surprising that unattractive people try to become more attractive?

My impression of many incels is that their looks are not their problem.

It's not like their opinions are written on their foreheads. Hit on a woman on tinder she won't know. Hit on a woman in a bar she won't know. Clearly the rejection is for simply being unattractive.

Visible attractiveness just gets you past the first gate. Some guys fail spectacularly at anything beyond that. Will fall on their face when chatting.

Personality is often very obvious through body language.

Oh certainly. Having a boring or timid or otherwise unattractive personality can be a big hindrance.

My teeth aren't that bad but are bad. My upper teeth are nearly perfect but my bottom middle 4 teeth are a little messed up. Most people can tell because I expose my upper teeth while talking, but if I smile it's pretty obvious they're not aesthetic... For years I've been ok with this, my parents never showed me to an orthodontist. But recently I'm getting more and more self-conscious about this every day. I searched a little about this and saw that, being 22, fixing them at this age is insanely expensive (up to 10k). I wonder if someone went through this treatment and can chime in whether this 10k is worth it?

I’m 35 and have had braces for over six months now. I kind of regret it because it’s purely cosmetic and a massive pain in the behind. I also cheaped out and got train tracks instead of Invisalign. Don’t do that.

Seriously consider medical tourism. I live in China so total cost is going to be just under $3,000. You might be able to go to Mexico or Thailand every two months for your teeth cheaper than getting it done locally. If you get crowns (veneers?) on your bottom incisors you can definitely get that done cheaper in Thailand than the US, including flights and a two week holiday.

Ah that makes sense! Will definitely look into medical tourism to Mexico. Thanks.

If they aren't going anywhere, you can clean them effectively, and the gums are happy, then maybe you don't care. But if they are getting worse, you can't clean them well, etc then you run the very significant risk that you'll be forced to do something about them eventually anyway (which is even more expensive)- better to do it sooner, before things start to deteriorate. I wish I could tell that to 22 year old me.

I have nearly identical teeth to yours, but I had braces and don't care that my bottom teeth or a little messed up since they're a lot better than they used to be. That said, there's some cheap(er) teeth-straightening companies out there nowadays.


I have not gone through such a significant procedure as yours, however I did get two of my bottom front teeth replaced, which ran around 2k.

Aesthetically, and durability wise, I'd say it's definitely worth it.

If they get the proper crowns, they are far more durable than real teeth, which is superb for a "tight mouth" such as mine.

Also see Weston Price's research from traveling around the world. https://en.wikipedia.org/wiki/Weston_Price

You ever wonder when they show a tribe from G-d knows where that had barely any contact with our civilization, how come they've got perfect white teeth and they've got them all? Nothing crooked, nothing missing.

I'm sure that this is caused by a number of reasons - some native american groups have very thick enamel, some groups have saliva that is naturally antibacterial for the types of bacteria that cause cavities (but from what I understand, this second trait is also associated with heart disease.)

It might be better to investigate these things based on the assumption that "G-d knows where" isn't a single place, and that all people that one considers primitive aren't the same people.

For example, you ever wonder when they show primitive people and their teeth are terrible, or when people that live in your culture spend no time on their teeth and never visit the dentist, but their teeth are fine?

Or how some people are naturally thin, and some have bone structures that seem like they were made to be fat?

Some form of dental hygiene is common worldwide. So, you can find young people anywhere with a clean smile. But, the worst cases get really bad.

Sadly, you will often see 40 year olds missing many teeth in those same areas.

I think a big part of it is that once you have even a minor cavity, eating anything sweet hurts like hell, so people just don't eat sweet stuff when they're older and have lost their baby teeth.

The feeling of a candy bar getting just right into the cracks of your molars is a great motivator for avoiding such things.

No refined sugar in the diet certainly plays a big part.

This interesting video talks about that. Time stamped to 6:51


No refined carbs → No cavities

Tough food, lot’s of chewing → No crooked teeth

Natural selection. If you got fucked up teeth out in the wild you are screwed. If you got fucked up teeth in civilization since the 1700s theyd just give you pig teeth or wooden teeth or whatever to get you chompin again.


I was born without "Wisdom teeth", which my Dentist claims is widely accepted as human evolution. (apparently the number of people born without them is growing)

But I also have a bad, and getting worse "popping jaw" issue. where my jaw pops (loud enough to make my ear ring for a while after) or locks up when under too much pressure or opened too wide.

Her advice is to eat soft food.... which seems to go against what TFA suggests we should be doing.

> apparently the number of people born without them is growing

I don't see what the selective pressure for this would be, since people with wisdom teeth just have surgery to remove them, so there's no real difference in terms of reproductive fitness right?

> people with wisdom teeth just have surgery to remove them

I think this is mainly a US and Australian thing: https://www.sciencealert.com/no-you-probably-don-t-need-to-g...

In Australia it's particularly bad. During a checkup my dentist casually mentioned how he'd be removing mine (at a later date), even though he could provide no reason for doing so. The cheeky bugger just assumed I wouldn't ask why!

Since then my trust in dentists has been further eroded by this Cochrane review https://www.cochrane.org/CD004625/ORAL_routine-scale-and-pol... that concludes with:

Authors' conclusions: For adults without severe periodontitis who regularly access routine dental care, routine scale and polish treatment makes little or no difference to gingivitis, probing depths and oral health-related quality of life over two to three years follow-up when compared with no scheduled scale and polish treatments (high-certainty evidence). There may also be little or no difference in plaque levels over two years (low-certainty evidence). Routine scaling and polishing reduces calculus levels compared with no routine scaling and polishing, with six-monthly treatments reducing calculus more than 12-monthly treatments over two to three years follow-up (high-certainty evidence), although the clinical importance of these small reductions is uncertain. Available evidence on the costs of the treatments is uncertain. The studies did not assess adverse effects (of the scale and polish treatment).

I know it's a bit of a joke that HN commentators assume they know more than the experts, so just to be clear: I consider the experts here to be the study authors.

It's more likely just race mixing, since if I remember correctly, native americans don't grow them.

I don’t know about you, but caffeine makes my jaw very tense and the popping bad.

If I manage to get through the three day come-down of caffeine cessation the popping goes away and my jaw starts to relax.


huh. I'm not sure I'm ready to do that... :-(

Howdy! Just saw your reply.

Are you aware of HN Replies? Email alleys for HN comment responses.


I got through the caffeine withdrawals last week. I haven’t had any caffeine since Monday last week.

Those first few days are unpleasant.

In addition to all the other arguments here (more chewing for bigger jaw development), I have another theory about tooth decay.

I think that pre-civilization humans did not eat much sweets past adolescence. This is because, as soon as a minor cavity starts developing, it hurts like hell to put anything sweet in your mouth. Sweet stuff was for children and adolescents, then we just stopped eating it.

> I think that pre-civilization humans did not eat much sweets past adolescence

Pre-civilisation humans wouldn't have had "sweets" as we know them. They would have occasionally had unrefined sugars through honey or palm sugar, and at certain times of the year had fruits (which most likely wouldn't even have been as sweet as they are now)

I see you're the same person that posted somewhere else, but for what it's worth, I agree that minor tooth pain is a great motivator not to keep eating things that will turn it into major tooth pain.

That pain is caused by nerve-connected dentin.

Unless the cavities go all the way through, recessed gingiva expose cementum that erodes, exposing dentin.

It's the same sugar-loving bacteria that inflame the gums.

Or there were not so much sweet things in the first place and only at certain times of the year.

I never had pain putting sweet stuff in my mouth when I had cavities.

I think that many toothpastes make our teeth less sensitive. I think it is supposed to reduce pain, but it can backfire...

This article implies that if you can't change your diet then you could achieve similar results with chewing exercises. The comments below mention mewing, but I suspect greater force would be better. Googling "chew toys for adults" gave interesting results but they are mainly used for anxiety and ADHD. Curious if anyone knows of a chew appliance for children or adults that would address the issues mentioned in the article.

Crooked teeth “run in my family” but mine are pretty straight.

I always attributed it to my obsession with ripping my teeth out as a kid. Weird, I know. I figured that it gave my teeth room to grow.

After reading this I’m curious if it was due to my parents doing baby-led weaning with me. They started it pretty young and always fed me whatever they were eating.

Human teeth development changed sometime during the industrial revolution when women were expected to work outside the home and breastfeeding norms were shortened from 3-4 years to more like 1 year. Or that's at least one interesting hypothesis from someone looking at old skulls.

Do you have a reference for this school of thought?

Do you have anything supporting that? My observation has been the kid loses interest somewhere between 1-2 years- the moms aren't cutting them off. Solid food is generally much more interesting.

As always, prevention is more important than treatment. Teeth problems can cause problems with mouth (lips), mandible and even facial structures. Braces can fix teeth if done properly, but it can hardly fix these secondary issues, especially for adults.

Ok, we know it's messed up. But, the question is how can we do better?

My hypothesis is that all the sugar from modern diets creates an environment where bacteria can grow and mess with the alignment of your teeth.

See the British and how the introduction of sugar into their tea created so many crooked sets of teeth.

Yeah, wisdom teeth are so annoying!

Excess protein intake (vast majority of diets, not exclusive to keto or paleo, etc.)

The article claimed that modern diets don't put enough strain on the jaw in childhood, so the jaw doesn't grow as much and there's more crowding. Has nothing to do with protein intake.

I suppose meat, as a protein source, is typically l chewier that fruit or veg.

Meat is easy on teeth, what traditionally wore down teeth in human history were rough unprocessed grains, tough vegetable fibers, nuts, and the use of teeth as tools (working plant fibers for example). Of course the inclusion of sand or grit in food also contributed. People also chewed a lot of bone in history, either whole or as with Aboriginal Australians, as a mash of whole animals.


>I remember asking my wife not to cut our daughters’ meat into such small pieces when they were young. “Let them chew,” I begged. She replied that she’d rather pay for braces than have them choke. I lost that argument.

If a distinguished professor in dental antropology can't stand up for himself for his daughters welfare in his field of study he's lost a lot of respect from me.

I see what you're saying, but standing up for something and winning the argument is not the same thing, and he only said that he lost the argument.

A scenario where one's wife doesn't believe in one's own scientific findings is another matter, which might ellicit thoughts about "standing up for yourself". Maybe that's what you were reacting to.

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