Comment by ivan_gammel | Hacker News Reader

Comment by ivan_gammel | Hacker News Reader

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It is definitely not that simple for a number of reasons. Yes, aligners and retainers in theory may be printed on some commercially available hardware. At your own risk, because you will be printing a medical device and you will need:

1. A treatment plan: simulated movement of teeth at every step, taking into account all forces. That’s specialized software or external lab service.

2. Precision. You put too much pressure at the wrong angle and you will need a surgery to fix the damage, because the tooth root moved in wrong direction.

3. Plastic. You cannot use ordinary 3D printer ink. You need a plastic that can survive the chemical environment in your mouth, maintain the pressure, and you probably want it to look good (no discoloration etc).

4. Finish: Align Tech, Straumann etc do not stop after 3D printing, there are few other steps involved to make sure there’s no sharp edges etc.

5. Maybe you will need attachments (to focus pressure in the right direction on certain teeth) or wires.

Align Tech is Apple of clear aligners, but now competition exists, producing aligners at scale is commercially more efficient, considering all the risks and required qualifications, and of course the best materials for aligners are patented and not sold OTC to everyone.

Disclosure: I worked at Align 10 years ago and later was CTO of European DTC competitor.

How many of these risks and problems are exaggerated in scope and potential due to both a desire for a regulatory moat and a general fear of litigation in the medical space?

That is to say, how good is “good enough” when done at small-scale in developing nations or medically underserved communities?

Smile Direct Club and co have shown its founded 100% in real risk of harm.

They were a company theoretically doing the same thing with still more resources than an average individual has, and ruined people's bites and teeth.

I don't think there's a good enough here

These kinds of things can slowly move your bone structure over time. After all, that is their entire point. You don't want to accidentally mess up your teeth and jaw even more.

This would be what I'd worry about. How many of us do any metrology on our printed artefacts? It's really easy to get a subtly warped print and without having some sort of calibration of the process I wouldn't want to make any accuracy claims whatsoever.

1. There‘s always a reason or two for the treatment. The problems with bite may affect your health in various ways. There’s aesthetic component in it, sometimes even cultural preferences for how your teeth should look like. But let’s say patient cannot afford to care about final position when signing up for the treatment. They just trust the doctor saying they need it. Failure mode: patient is unhappy with outcome and will ruin your business from marketing perspective.

2. Let‘s say the practice does it in old way, with impressions - no intraoral scanner. The scanner of impressions still needed, but it can be cheaper. Someone needs to build it and achieve required accuracy (let’s say, 50 μm). Who? Why? Failure mode: bad scan leads to aligners not fitting your teeth from day 1. Oops.

3. Let‘s say someone builds a good OSS alternative to OrthoCAD (Who? Why?), so that orthodontist on site could build a treatment plan and export it into series of 3D models for printers. Failure mode: good treatment plans are rarely possible or output is garbage (aligners do not fit, cause pain etc)

4. Maybe some company develops good plastic or patent expires, so that it is possible to produce it in India, China or other inexpensive location with strong industrial base. That would be cool, otherwise: non-compliant plastic breaks in patient’s mouth, decomposes with patient ingesting some toxic chemicals or is simply not strong enough to move teeth in desired position, so you have problem with 2nd aligner.

5. Maybe you get to this point, but you still need a printer that can maintain the same precision in printing. And you need a good cutting and finishing process. Someone needs to build such device. Failure modes are similar to the mentioned above.

6. The ortho supervision sounds easy, but how many patients in developing countries do even have a possibility to see orthodontist? They are definitely not in position to treat themselves.

So, in this process, what is good enough exactly? Who and why would drive the costs down while building an on-site solution?

Per point #3, aren't the liners thermo formed around at 3d printed model of your teeth?

IIRC, yes. It’s been some time ago, I don’t know how manufacturing looks now. It’s different process compared to 3D printing at home. It doesn’t mean it should be different, it just has to maintain certain properties. I’m not chemical or bioengineer to go into detail of it :)

Yes just the safe to be in the mouth and for it to handle significant pressure from teeth biting changes this from simple 3D filliment to something much more involved during the design and regulatory processes.

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