alt.hn

12/30/2025 at 9:22:53 PM

Humans May Be Able to Grow New Teeth Within Just 4 Years

 https://www.popularmechanics.com/science/health/a69878870/human-new-tooth-regrowth-trials-japan-timeline/

by rmason

12/31/2025 at 12:34:30 AM

Popular Mechanics is like Popular Science right? Extremely bullish on new technologies to the degree of taking one study and turning it into a breathless article about how we're 1 year away from flying cars?

Sorry for the cynicism, but I grew up subscribing to Popular Science and I gained a very jaundiced view of this kind of science/technology popularizing

by throw4847285

12/31/2025 at 12:54:09 PM

Yep, you nailed it.

by intothemild

12/31/2025 at 8:17:35 PM

Yes, they loved the moller sky car, frankly these magazines would have been great if they just accurately caveated stage of development and leaned into a speculative "The World of Tomorrow" attitude for these types of things. As a result of NOT doing that they really poisoned people against the very idea of progress (of which we make a ton.)

by fellowniusmonk

1/1/2026 at 2:18:29 AM

I wonder if at the time the "world of tomorrow" is how we think of it now with fondness.

by twosdai

12/31/2025 at 3:06:03 AM

Unrelated to the growth topic, but related to teeth.

5 or something years ago I read here, on hn, about novamin/biomin and started to buy toothpaste with it.

Since that I had 0 cavities, even if my toothcare routine isn’t the best: most of the time I brush only in evening and when I had severe clinical depression episode I could go weeks without brushing.

by galkk

12/31/2025 at 9:30:02 AM

Sort of tangential: I used to be able to tell episodes of depression were setting in because I'd stop brushing my teeth. It was the clearest indicator I can recall.

I'd then brush my teeth hoping it would cure the depression. It clearly worked, because I'm no longer depressed. It just took a few years to kick in.

Always remember to brush your teeth.

by steve_adams_86

12/31/2025 at 1:43:06 PM

OK, and my anecdote is that for forty years I used no toothpaste at all, brushed only before bed, didn't floss, never went to the dentist, and had perfect teeth. The conclusion of this limited study is: whatever.

I guess I should admit that eventually I got lazy and skipped a night, and immediately got a cavity that led to having a tooth removed, and now I use toothpaste and floss. But still, anecdotes, what are they worth.

by card_zero

12/31/2025 at 2:53:39 PM

I learned that dentists make their money by doing procedures that have little overhead and high returns.

I read about patients who would go one dentist that said they found X cavities and then go to another dentist that would say 'zero' were found.

I tested it myself when I was told I required extensive cleaning beneath the gums and the next dentist, who has a 3 month waiting list, said it was not required and my teeth were fine.

I no longer believe any dentist and considering most are now private equity operated it makes sense.

by pizzafeelsright

1/1/2026 at 6:45:36 PM

I believe there is high correlation between "needing additinal work" and how new the building, furniture, provider is...

by jrs235

12/31/2025 at 3:28:57 AM

Do you eat much sugar? Soda or juice? These things make a huge difference. So does age. Young people get cavities easier than somewhat older people.

by wakawaka28

12/31/2025 at 5:50:13 AM

Is there also not a some genetic aspect there? It is a question as I do not know but always assumed as I always did whatever and have 0 cavities or anything else that other people seem to have and I am almost 60. Never have receding gums, sensitivity, cavities or anything else since I was born.

by anonzzzies

12/31/2025 at 6:07:39 AM

There is a genetic aspect I'm sure. But I think most people don't avoid consequences of, say, drinking lots of soda while not brushing teeth. I bet there are nutritional factors too. If you are chronically malnourished, your teeth may be worse somehow.

I think regularly brushing your teeth and getting cleanings makes a big difference obviously. Gum disease or gingivitis mainly happens to people who have long-term dental care issues or certain bad habits.

by wakawaka28

12/31/2025 at 4:00:54 PM

It's actually really bad to brush teeth just after drinking soda because the acidity of the CO2 softens the enamel. Better to wait a while. That's what my dentist said anyway.

by wolvoleo

12/31/2025 at 8:25:12 PM

Maybe so, but at least rinse your mouth ASAP.

by wakawaka28

12/31/2025 at 7:11:59 AM

I drink sugar free sodas all my life.

by galkk

12/31/2025 at 5:21:39 AM

Counter-anecdote, I did the same, got Burt's Bees with novamin when they still sold it (discontinued), then switched back to Crest. I prefer the Crest. No cavities either way, but tooth sensitivity and clean feeling differences. A tooth chip I wondered might remineralize, i.e. grow back or fill in or something, had no change.

My guess is the SLS detergent, present in Crest and not in Burt's, is the more significant factor.

by edgineer

12/31/2025 at 6:16:43 AM

I always had sensitive teeth (and brush exclusively with sensodyn for many years) so I guess this is less of a factor for me.

I buy Canadian? Sensodyne that has novamin in it.

by galkk

12/31/2025 at 7:40:28 AM

Any idea about mHAP (hydroxi apatite)

by CrimsonRain

12/31/2025 at 12:47:03 PM

You can do the same by just kissing a person with the right mouth biome.

by animal531

12/30/2025 at 11:26:10 PM

This is like fusion energy. It's been 4 years away since I've been a child.

by TylerE

12/30/2025 at 11:31:59 PM

I personally regrew my teeth since I was a child. Granted, once.

by amelius

12/31/2025 at 12:21:21 AM

Fun fact - all of your adult teeth were already there from the start, hiding under(inside?) the gums. We don't "grow" new teeth when the baby teeth fall out - the adult teeth were always there under them.

by gambiting

12/31/2025 at 2:31:21 AM

It may be fun, but it's not a fact. At birth, you likely have all the tooth buds to grow your primary teeth and maybe your permanent molars. Premolar and canine buds typically form during the first year of life. Second molar buds form around age two. Third molar (wisdom teeth) buds don't begin developing until around age five to six and in some folks they don't grow at all.

I have a condition where my lower front permanent teeth never developed. We weren't sure if any of our kids would have the same issue so we discussed it with the dentist. They couldn't tell us if all the permanent teeth were present or developing because there hadn't been enough time for first xrays to show all of the permanent teeth buds growing. Even at age 3.

by tstrimple

12/31/2025 at 2:52:30 AM

This is not true. I’ve seen x-rays of a child’s mouth with clearly no adult teeth visible below the gums. Later I’ve seen X-rays of the same mouth with one or two adult teeth below the gums where baby teeth are about to fall out. The adult teeth are there underneath once the baby teeth fall out but they are not there “from the start”. That isn’t even to mention the size problem.

by rokob

12/31/2025 at 10:06:35 AM

so I used to think this (till this past week), it's not quite true. Yes, ther are images of showing child skulls with lots of teeth. those are generally hyperdontia.

A regular child skill looks more like this x-ray

https://ccdcsmiles.com/userfiles/651/images/IMG_4253.jpg (from a dental clinic I found while searching).

Yes, you can see the adult teeth, but not all of them, and not like the hyperdontia cases.

by compsciphd

12/31/2025 at 1:06:20 AM

Did they get bigger as you were "Growing up"? Then we grow teeth, you're just being pedantic about whether they're brand new or not.

by dekhn

12/31/2025 at 1:41:03 AM

It's not pedantic in this context unless you already have a way to set up fresh seed teeth.

by Dylan16807

12/30/2025 at 10:48:33 PM

Confused a bit by the article: it mentions human trials began in september 2024, but also that the trials that might prove it working are yet to start?

by Fraterkes

12/30/2025 at 11:13:46 PM

I think it's just poorly written. If you go to the source[1] the trial period was planned from September 2024 to August 2025, and the submission says people are "undergoing" a trial. Perhaps it got delayed, or, more likely IMHO, the trial period is over and they're studying the data so haven't made reached a conclusion yet.

[1]: https://www.kitano-hp.or.jp/info/20240503

by magicalhippo

12/31/2025 at 12:21:43 AM

It’s a phase 1 clinical trial designed only to assess safety and determine the appropriate dosage. Future trials will focus on efficacy.

by MajesticHobo2

12/31/2025 at 2:17:18 AM

I’ve heard this for the last 20 years.

by abootstrapper

12/31/2025 at 4:35:14 PM

BugsJustFindMe's Law of Headlines: Any headline that uses the words "May", "Might", or "Could" is equally true if those words are replaced by "Won't".

by BugsJustFindMe

12/30/2025 at 11:12:49 PM

Aren't the shape/size/placement/etc. of human teeth fairly unique across different individuals? At least unique enough to use dental records to identify bodies.

I don't see if mentioned in TFA, but if new human teeth can be grown is it expected that the new ones will just grow in "correctly" to fit a person's mouth?

by bumblehean

12/30/2025 at 11:30:29 PM

> At least unique enough to use dental records to identify bodies.

Yes but in comparative dental analysis they use ante-mortem dental records to compare with post-mortem remains. It's not like DNA where you can record it once and then use that to match samples decades later in a database. In order to have a high confidence in a match, recent x-rays and records of dental work like fillings, crowns, etc. work best.

And no it is not expected. It's one of the primary challenges with bringing these kinds of drugs to market, as hyperdontia is already relatively common among humans (I had an incisor growing at the roof of my mouth an inch behind my row of teeth). Most successful applications of these tooth regrowth drugs tend to place them near the root of missing teeth hoping that the cellular growth signaling mechanisms are still working.

by throwup238

12/30/2025 at 11:14:20 PM

Teeth wear quite a bit too, I wonder will new ones have to be pared down to fit.

by clickety_clack

12/31/2025 at 10:53:10 AM

I've been hearing this for as long as I can remember and I'm not young anymore.

by ezoe

12/31/2025 at 3:27:49 PM

Great idea but I'm sure it will be for the rich.

by nephihaha

12/30/2025 at 10:52:54 PM

I've been taking vitamin k2 mk4 at 45mg a day for over a year now. My teeth feel gr8. Now I need to get some of this stuff to have super human chompers.

by zingababba

12/30/2025 at 10:58:25 PM

What changes in your subjective sensation of your teeth with K2?

by epicureanideal

12/31/2025 at 1:08:22 AM

This guy's been downvoted badly but he's right - vitamin k2 make your teeth into "superteeth".

I started K2 about 10 years ago. Next dental checkup (about a year too late) the dental tech said my teeth appeared recently-cleaned. This has continued since then. No cavities, little cleaning required other than regular brushing, flossing and taking k2.

by giardini

12/31/2025 at 3:41:45 AM

IIRC plaque is mineralized by saliva in the same way as tooth enamel, so something that changes saliva in a way that prevents tartar from forming might be reducing the amount of calcium in your saliva in a way that could potentially ultimately not be good for your teeth.

by resoluteteeth

12/31/2025 at 1:14:02 AM

Why mk4 over mk7?

by terribleperson

12/30/2025 at 11:35:53 PM

Let’s hope teeth won’t grow in places they shouldn’t.

by piskov

12/30/2025 at 11:46:51 PM

a haircut made of teeth though, hmm

by wellthisisgreat

12/31/2025 at 12:33:00 AM

We all shoult fear the vagina dentata.

by krater23

12/31/2025 at 3:02:29 AM

Old news. They were doing this with ultrasound successfully 20 years ago. I know a guy who a tooth back with his own device.

by valunord

12/30/2025 at 11:22:57 PM

Growth rate and how you don’t mess it up before it matures are problems

by m3kw9

12/30/2025 at 11:21:44 PM

Scientists regrowing everything except hair. Fuck my life.

by msuniverse2026

12/31/2025 at 12:35:19 AM

I am hoping for advancements in cartilage growth. I underwent microfracture surgery in my knee and will eventually need a replacement unless we make progress in this field. I would prefer to avoid knee replacement if possible because I enjoy being active. I am hopeful we’re getting close.

by cebert

12/31/2025 at 12:02:53 PM

In the summer my knees were so wrecked I could barely make it up and down the stairs. My GP first thought it was an inflammation and prescribed something for that, but when I went back after a couple of weeks he said the cartilage may have worn off and prescribed me Flexofytol. It may be placebo effect, but between taking it a bit easier, cycling more, and the flexofytol, my knees are the best they've been since I injured them in the first place.

by tmtvl

12/31/2025 at 12:51:58 AM

Anecdotal, but I was going in for carpal tunnel work and ran into an older gentleman, probably early 70s, that had just gone through a knee replacement a week earlier. He was walking around on it and said he wasn't really in any pain.

I was amazed.

YMMV.

by esseph

12/31/2025 at 1:31:12 AM

I have heard great things about knee replacements. Unfortunately, I’m relatively young (late 30s). If I were to get a replacement now, I’d likely need another one when I’m older. Additionally, I imagine getting an artificial knee replacement would make you no longer a candidate for lab-grown replacements. There is an option already where they can grow your cartilage in a lab, but it’s quite expensive, and my insurance will not cover it.

by cebert

12/31/2025 at 7:47:47 AM

$4k and a trip to Turkey. I did it last tear and can recommend :)

by kolinko

12/31/2025 at 5:39:19 AM

My meniscus would like a word.

by gensym

12/30/2025 at 11:24:34 PM

And limbs.

by xenospn

12/30/2025 at 11:34:26 PM

I would say every tissue: no bones, no organs, eyes, ears, nerves, skin.

Like what can they grow?

by piskov

12/31/2025 at 1:15:58 AM

Well, I'm personally hoping stem cells pull through for corneal tissue regrowth. I've got significant scarring in one eye. I'd rather not get a donor (cadaver) cornea sewn on if it's avoidable but we'll see.

I think they're making progress.

by kylecazar

12/31/2025 at 12:36:53 AM

The liver is an exception here - you can grow back a lot of it.

by janice1999

12/31/2025 at 10:59:32 AM

Not many times tho: see cirrhosis

by piskov

12/31/2025 at 3:20:34 AM

Eh? They can grow skin cultures that are good enough to help burn victims. Not, like, with all the pores and follicles being there, but it is skin…

by drdeca

12/30/2025 at 11:26:02 PM

finasteride + minoxidil

by zaken

12/31/2025 at 3:23:39 AM

Finasteride can make you have man-boobs, it’s a known side effect

by b3ing

12/30/2025 at 11:30:38 PM

Once the follicle is closed/gone, it’s gone.

Minoxidil won’t help grow hair on a patch of bold skin. After that only hair transplantation

by piskov

12/30/2025 at 11:44:45 PM

I'm sure you're correct. That said, I saw a friend who went bald at 28 get all of his hair back from Minoxidil + finasteride. Maybe his folicles weren't closed/gone but he was bald and a year later, was not.

Apparently there's also now-a-days, Micro-needling, Stem Cell Therapy, Platelet-Rich Plasma, and others. No idea how effective they actually are

by socalgal2

12/30/2025 at 11:55:09 PM

Well he even had alopecia or he got hair transplant. There is sadly no other option.

by hsuduebc2

12/31/2025 at 3:24:13 AM

What does that mean? Alopecia is the general term for hair loss.

by dpark

12/31/2025 at 5:16:06 AM

Sorry my bad. It's called that way in where I'm from. The hair loss is mostly due to mechanism similar to pattern baldness but the hair loss can occur even without death of hair follicles. It could also be triggered by some autoimmune disease.

by hsuduebc2

12/31/2025 at 3:19:48 AM

This isn’t the whole story. Many people have follicles that are dormant. Many people have success regrowing hair on bald spots with minoxidil and/or finasteride.

If you look like Sir Patrick Stewart, yeah, that’s not growing back. A bald spot might fill in with medical treatment though.

by dpark

12/30/2025 at 11:30:38 PM

If you don't have sides that is

by simmerup

1/1/2026 at 4:09:29 AM

Same like curing baldness, every 5 years there's a new medicine which doesn't work.

Teeth are orders of magnitude more complex than hair follicles.

by coolThingsFirst