
I made my own clear plastic tooth aligners and they worked - dezork
http://amosdudley.com/weblog/Ortho
======
rl3
Not to be a downer, but was any thought given to the safety of the plastic(s)
used?

This is something that's in your mouth a lot and constantly exposed to saliva.

The _Dimension 1200es_ mentioned doesn't appear to be specific to medical
applications.[0] The product page lists the only compatible thermoplastic
being _ABSplus-P430_. The MSDS for that basically says the stuff is dangerous
in molten form, and beyond that there's very little data.[1] The same company
makes "Dental and Bio-Compatible" materials for use with their other products,
and these appear to have considerably more safety data.[2]

> _The aligner steps have been printed, in addition to a “riser” that I added
> in order to make sure the vacuum forming plastic (sourced from ebay) ..._

As another commenter pointed out, the vacuum forming plastic is probably the
primary concern because the 3D printer was just used to create the molds. The
specific type of vacuum plastic isn't mentioned.

Regardless, very neat project.

[0] [http://www.stratasys.com/3d-printers/design-
series/dimension...](http://www.stratasys.com/3d-printers/design-
series/dimension-1200es)

[1]
[http://www.stratasys.com/~/media/Main/Files/SDS/P430_ABS_M30...](http://www.stratasys.com/~/media/Main/Files/SDS/P430_ABS_M30_ABS_Model/SDS-
EU-P430-US-English.pdf?la=en)

[2] [http://www.stratasys.com/materials/material-safety-data-
shee...](http://www.stratasys.com/materials/material-safety-data-
sheets/polyjet/dental-and-bio-compatible-materials)

~~~
dezork
I used Keystone PROFORM .030" Retainer Material. Keystone is a dental
supplier, so I trust the plastic is biologically inert.

~~~
amelius
This whole issue should be mentioned in the article, just in case anybody
ignorant wants to do this with unsuitable materials.

~~~
dezork
Good point. I'll add some info about this.

------
jeffchuber
Awesome work!

The animation definitely seems the most difficult (and subjective), but also
the most cool! Body hacking via computed geometry!

Invisalign (align technology) uses almost the same workflow. Market cap
$5.89B.

If you could move the workflow over to something based on WebGL / three.js -
you could make this accessible to dentists in developing countries. Could be
an awesome open source project.

I think "allowing" it to be used in the US would open yourself up to too much
liability though :(

~~~
underwater
Invisalign seems to be mostly used for cosmetic fixes. That doesn't seem too
compelling for a dentist in a developing country.

~~~
gregschlom
People in developing countries need and want to look good just like everybody
else. "Developing country" is pretty much the whole world, except Western
Europe, North America, Japan, and Australia / NZ.

~~~
Void_
Do you imagine people in countries east of Austria as ugly bunch with crooked
teeth, because we're developing and never heard of cosmetic dentistry?

~~~
cbd1984
Actually, the usual place to stereotype as having crooked teeth is the UK,
which is firmly in the "developed" group of countries.

To answer your question, no, "crooked teeth" isn't in the usual list of
stereotypes people have about Eastern Europeans.

~~~
dazzla
IMHO in the UK teeth straighting is perceived as extremely vain. So in the UK
straighting teeth is more a taboo than not.

~~~
tfgg
Huh? Orthodontics are free in the UK up til 19, and it's very normal to have
braces.

Maybe amongst an older generation who'd have to go out their way to pay for
straightening.

~~~
dazzla
Again I show I have been away from home to long.

------
loocsinus
It is smart that you designed the retainers based on maximum tolerance of
tooth movement quoting from a textbook. I suggest you take X ray to make sure
no root resorption have occurred. Also for those who want to imitate, measure
the length of teeth and compare with the arch length to make sure the teeth
can actually "fit" into the arch. I am a dental student.

~~~
an_ko
By "length of teeth", do you mean their width measured along the arch of
teeth, or vertically?

~~~
loocsinus
In this case: the width. aka the "mesial-distal" length.

------
percept
Now _that_ is awesome--those things aren't cheap.

I'm going to send this to my dentist (who's cool enough to appreciate it).

~~~
rev_bird
It has not once in my life occurred to me to email my dentist.

~~~
percept
I know--mine _texted_ me the night after my filling, to see how it was coming
along.

She does that for everybody, along with a number of other practices that do
her and (would) her profession great credit.

~~~
thrw1122
Are you in SF? If so, who is it - I am looking for one :) thx.

~~~
percept
Nah, but I found her on Yelp.

------
forgotpasswd3x
This is really amazing, man. It's honestly the first 3D printing application
I've seen that I can see quickly improving thousands of lives. Just to think
of all the people who right now can't afford this procedure, that soon will be
able to... it's just really wonderful.

~~~
dikdik
Next I need someone to do orthopedic shoe inserts. Mine cost $600 and only fit
my running shoes.

~~~
ghufran_syed
I'm a physician, and I used to get custom made ones, until I found these for
around $45 in the US:
[https://www.drscholls.com/productsandbrands/customfitorthoti...](https://www.drscholls.com/productsandbrands/customfitorthotics/)

~~~
pitaa
I was having foot pain a few years ago and decided to give those a try before
shelling out to see a podiatrist/get custom orthotics. My foot pain was gone
within a week and only came back on one occasion; when I bought new shoes and
forgot to put them in the new pair.

Still, I've wondered if I'm missing out by not getting custom inserts. It
sounds like (at least in your case) there was no major difference?

------
valine
He scans his teeth, animates how he wants them to move in blender, and then 3D
prints each frame. That is absolutely brilliant.

------
daveguy
It looks like the author took into account the safety of the plastic in
creating these, which is a good thing. Maybe more so than dentists. You know
"silver" fillings aka dental amalgum? They are 50% mercury by weight and are
still being used. Supposedly safe because it is inhalation of mercury that is
poisonous. Removal of those fillings with a drill can be dangerous. When some
guy told me about this and was talking about it being the next
asbestos/mesothelioma, I was thinking "sure! That sounds like conspiracy
crap!" Then I looked it up on the FDA site like he suggested:

[http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedur...](http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/DentalProducts/DentalAmalgam/ucm171094.htm)

Anti-vaxxers are idiots and it is obvious that vaccines don't cause autism
(original study was a fraud). The health benefit of vaccines is as undeniable
as the lack of correlation to autism.

That said, dental amalgum is a chunk of mercury in your mouth. FDA says it is
safe for people over 6yrs old, but I personally will stay away from it for any
future dental work.

~~~
Grishnakh
The thing about the mercury amalgam fillings is: why even bother any more?
Modern resin fillings are mercury-free, plus they look far better and are
nearly indistinguishable from real tooth. They're stronger too: I have a resin
"filling" that's actually filling in a chip on one of my front teeth, meaning
this filling is actually shaped into a sharp biting edge. It's been there for
a year now and works fine. You can't make tooth repairs like that with
amalgam.

Amalgam is just plain obsolete, regardless of how safe it may or may not be.
So why anyone still uses it, I have no idea; I can only guess they're cheaper
than the resin fillings, so they're used for low-income patients, or by shitty
(or old-timer) dentists trying to improve their bottom line.

~~~
tonyarkles
Price, yes. I got mine when I was a student and had no cash; I had a hole in
my tooth and had to get it filled for the lowest cost I could.

If I have to get more... It'll be resin. The amalgam ones I've got have lasted
a long time though, and I don't seem to have any new holes now that I've quit
drinking so much soda every day :)

------
minsight
This is just amazing. I was waiting for how it might go horribly wrong, but
the guy's mouth looks great.

~~~
_jomo
Looks like quite a bit of an overbite, though.

------
wslh
There is an important issue missing in the article (beyond the warning
notice): the occlusion. The modification of the dental structure requires a
whole functional analysis that goes beyond the teeth.

Anyway, the future is promising and the issues could be solved taking into
account all the factors.

~~~
lpsz
Would you please elaborate more in layman's terms?

~~~
wslh
Your occlusion/teeth position is not arbitrary and it impacts other parts of
the system like the maxilla, the mandible, and even your tongue. Changing it
only based on aesthetics can unbalance the forces that you were applying
before the treatment and other issues can appear.

This doesn't mean that every dentist really cares about this issue but you
should search for a professional who cares about this.

------
rashkov
I came across an article here on HN about mail-order Invisalign companies at a
fraction of the price. I'm about half way through and very happy with the
progress so far. Just thought I'd give a heads-up if anyone is interested

~~~
zump
Link?

~~~
rashkov
This was the article: [http://mobile.nytimes.com/blogs/well/2015/02/01/a-trip-
to-th...](http://mobile.nytimes.com/blogs/well/2015/02/01/a-trip-to-the-mail-
box-not-the-orthodontist/?referer=)

I went with smilecareclub. They're pretty hands-off but it gets the job done
and is a good value

~~~
emehrkay
I wonder how this works, they added brackets on my teeth that act as anchors.
Definitely worth the try, I believe that I paid 3k for my treatments, this is
~600. Amazing

~~~
rashkov
They do not add brackets / anchors but they do use a straight-across aligned
as opposed to a more trimmed "scalloped" aligner. The straight across gets a
bit more turning force because it goes higher up and covers a bit of your
gums. I'm no expert so I don't know if that's the whole story. They definitely
filter out people with more complicated alignment issues so that could play a
role as well.

------
CodeWriter23
The work he did with the impressions, to me, suggests he has experience as /
knows someone who is a dental technician. If he didn't, wow, he independently
figured out some of their key techniques.

My grandfather used to make dentures, and that casting in the 4th photo looks
exactly like the impressions my GF would make. They also used these hinges so
they could mate the upper to the lower, so they could adjust any collisions
that occurred while opening and closing the mouth.

~~~
dezork
Nope, no prior experience. It's quite easy, if you have an impression tray (I
had to mock it up in 3d and print one). The instructions for alginate are
right on the bag.

The rest was just reading freely available docs on how to make castings.

~~~
yathern
Hey! Recent NJIT alumn - great to see something so creative like this come
from my home turf. Really impressive work!

~~~
dezork
COAD?

------
hamburglar
Having recently done invisalign, I think this is brilliant, but I would have
had a really hard time sticking with it through the pain. I would worry too
much that I was doing damage. My case was quite a bit more severe, however, so
maybe it's less of a big deal if the movements are minor.

------
teekert
This also seems to have whitened his teeth at the same time ;), typical
"before, after".

But on a serious note, I had braces, after the were remove a wire was placed
behind my teeth to keep them in place. It didn't stick to one of my ceramic
teeth I had from an accident in my youth. The wire was removed and after some
months my front two teeth were as far apart as ever. Ok, the overbite didn't
return but things will move back at least to some degree over time.

As mentioned before, I myself would never just put any plastic material in my
mouth with all the bad things known about plasticisers, bpa/bps, etc.

~~~
dezork
I've been using 30% Carbamide Peroxide whitening gel in the trays for about 30
minutes a day. So yes, they are whiter.

~~~
KRuchan
Could you share a link if it can be bought online?

------
racecar789
Another option....have a dentist bind composite material to the couple teeth
out of alignment.

Had two teeth done for under $500 10 years ago.

It's a stop gap until braces are an option financially.

------
zump
Now THIS is a hack.

------
vaadu
How soon before the FDA says this is illegal or the medical industrial complex
lobbies congress to make this illegal?

~~~
schoen
It seems likely that there would already be FDA regulation in the U.S. if you
marketed this to another person, plus unauthorized practice of dentistry
considerations if you didn't have the relevant professional training and
licensing. But my impression is that these regulations don't apply to medical
devices that you make and use yourself on your own body.

------
hellofunk
This is cool but I can't say I agree with actually doing it. Just because you
_can_ do something doesn't mean you _should_ , particularly in matters of
health. If you don't have the requisite experience and knowledge and training,
it seems risky to go about something like this on your own.

~~~
ryandrake
No more risky than changing your car's brake fluid (risk of death if you do it
wrong). A lot of services that we have been conditioned into thinking need to
be administered by specialized professionals with N years of expensive
schooling, can probably be DYI'ed with access to the right equipment / tools.

------
KRuchan
Kudos to him for doing this, but I am slightly concerned that he has
introduced overbite [1] in his jaws looking at the before and after pictures
:(

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

------
Tepix
I love this project - well done, and the result speaks for itself! It's
unfortunate that you were forced to go this somewhat dangerous route due to
money. In some countries dental care like that would be paid for by the health
insurance.

------
stefanix
Made my own as well when I was interning at an othodontist.

There is not really much tech required. You can simply cut apart the gypsum
model tooth by tooth and align it perfectly with wax and add space for you
gum. Finally create a mold and use medical grade silicone to make the tooth
straightener.

Silicone also allows for more movement and gives you control of upper and
lower teeth in relation to each other.

While this is not rocket science there are considerations about jaw alignment
that would be difficult for the amature to get right the first time around in
any but simple misalignments.

------
ck2
This is definitely for the brave, not me.

Not sure what I would do if we didn't have a dental school.

When I go there I am always surprised to find people who actually have
insurance who still go there despite all the hassle.

------
yogipatel
I'm not trying to downplay how much the hacker/geek in me loves this, however,
as a former* dental student, I would highly suggest _not_ trying to pull this
off on your own.

First, teeth and their movement is more complicated than it might first seem.
You have to think about the entire masticatory apparatus, for example:

• There's more root than crown, how does the root move in relation to the
tooth? Root resorption is a common problem in orthodontic treatment.

• Is there / will there be enough bone surrounding the tooth to support the
intended movement?

• How will the patient's occlusion (how the teeth fit together) be affected?
Part of the Invisalign process is to take a bite registration that shows the
upper and lower teeth in relation to each other. This is important, and
ignoring it can potentially lead to other complications:

\- stress fractures

\- supraeruption of opposite tooth

\- TMJ pain

• Does the patient display any parafunctional habits that will affect the new
tooth positions? For example, do they grind, clench, or have abnormal chewing
patterns?

• Many Invisalign techniques require the placement of anchors, holds, and
various other structures attached to the teeth themselves. They allow for more
complex movement than the insert itself would be able to provide.

• Adjustments are often required mid-treatment. Not everybody’s anatomy and
biology is exactly the same, so you have to adjust accordingly.

Now, does every general dentist take this into account 100% of the time? No,
but they’re at least trained to recognize these situations and compensate for
them.

That said, many simple patients don’t require any more thought than the OP put
in. It’s a good thing he looked in a text book and realized that there’s a
limit to how much you should try to move a tooth at each step before you’re
likely to run into problems. And if you do run into problems — do you think a
professional is going to come anywhere near your case?

A few issues I have with his technique:

• Unless he poured his stone model immediately after taking the impression,
it’s likely there was a decent loss in accuracy. Alginate is very
dimensionally precise, but only for about 30 minutes. The material that most
dentists use, PVS, is dimensionally stable for much, much longer (not to
mention digital “impressions”).

• Vertical resolution of the 3D print _does_ matter. You might be moving teeth
in only two dimensions, you’re applying it over three dimensions.

Again, I think it is awesome that someone gave this a shot, and did a fairly
good job as well. I’m all for driving the cost of these types of treatments
down, as well as promoting a more hacky/open approach to various treatments.
Just know there’s more than meets the eye.

* I decided to go back to tech, there’s too little collaboration in dentistry for me to make a career out of it.

------
semerda
Wow this is awesome! Thank you for sharing. Retainers post Invisalign cost
between $400-900 for 1 set - total ripoff. This looks like a far cheaper
alternative.

------
scep12
Awesome stuff Amos! It's always nice to see creativity and persistence
rewarded with successful results. I really enjoy reading these types of posts
on HN.

------
syberspace
slightly off topic: how is diy tooth alignment going to affect criminal
investigations? on all those crime shows on tv (csi, navy cis, ...) they use
dental records to identify otherwise unidentifyable bodies. is this method
even used in real life and how would they find any records of your teeth if
you fixed them yourself?

------
muniri
This is awesome! Definitely not the safest thing to do, but I'm glad that they
worked.

------
justinclift
Cool, that's an idea I'd had in the back of my head for some time too. Good to
see someone's gone ahead and done it, and proven the concept. :D

------
vram22
Interesting article. Waterpik is a related product (as in, for teeth and gums)
that a dentist recommended. Anyone have experience using it - pros, cons?

~~~
cptvideo2
I think Waterpiks are better for dental health than toothbrushes and floss
combined (although I use ‘em all). They’re basically small-scale pressure
washers that obliterate bacterial biofilms, which are the real cause of tooth
decay and gum disease and bad breath. Your mouth feels a different kind of
clean after 2 minutes with one of these things.

~~~
vram22
Didn't know about biofilms (bacterial or other) earlier. The basic idea is
intuitive (which is why I gargle with salt water regularly), but googled
biofilm now and found a lot of info - it is complex. Thanks for mentioning it!

Saw this:

[https://en.wikipedia.org/wiki/Biofilm#Biofilms_and_infectiou...](https://en.wikipedia.org/wiki/Biofilm#Biofilms_and_infectious_diseases)

[https://en.wikipedia.org/wiki/Biofilm#Dental_plaque](https://en.wikipedia.org/wiki/Biofilm#Dental_plaque)

The article says:

"Biofilms have been found to be involved in a wide variety of microbial
infections in the body, by one estimate 80% of all infections"

------
squizzel
Is it me or did it whiten your teeth. I noticed a big difference in upper
plaque between the before and after picture.

------
burgessaccount
This is awesome! Thanks for the detailed description.

------
mentos
Are you considering starting a business out of this?

~~~
dezork
Definitely not, because of liability, and the fact that I have no interest in
other people's teeth.

I'm happy to leave it as a piece on my portfolio :)

~~~
sandGorgon
But it would be great to build open source software that does this at a
pushbutton.

------
pcurve
this is pretty amazing and daring.

I guess this would work better with those with gaps or very mildly crowded
teeth.

Often crowded teeth result in pulling teeth to make room.

------
z3t4
Considering opportunity cost of the 100+ hours that probably went into this it
would be cheaper to go to a dentist.

He might be able to come up with a better or cheaper method then the currently
industry standard though ...

------
transfire
Can you chew food with the aligner on?

~~~
dezork
Food finds its way up between the aligner and the teeth, and it's very
unpleasant. Not recommended.

Drinking is not a problem though.

~~~
KRuchan
Most orthodontists will say anything except water is a no-no - coffee and tea
will stain your aligners, and they almost always permeate the aligners into
your teeth, causing decay until the next brushing. Juice is even more harmful
with the sugar and fibre. Also, hot beverages can deform the aligners. I know
cases of people who tried having drinks with straws, and realized it wasn't a
viable solution. The drink still ends up permeating the aligners.

------
hardtime
Nice work. I have braces so...

------
darksim905
Very very awesome job :-)

------
peleroberts
Direct leak into your gums..

------
brbsix
Orthodontics is a field known for its protectionism. It'd be pretty foolish
but I wouldn't be surprised if you receive a cease and desist.

