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.
That is to say, how good is “good enough” when done at small-scale in developing nations or medically underserved communities?
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?
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
They used a specialized sort of 3D camera on a stick to get an incredibly accurate model of my mouth, any open source solution would need an equivalent. And you’d also need open source code from somewhere to work out which teeth need to move where and at what stage in the treatment.
The 3D camera was really neat. A little faster, and I didn’t once dry heave.
I could watch the software and a 3D model slowly form of my mouth. Looked surprisingly user friendly. Missed areas were highlighted, for example.
Dry heaving would have been great. I would regularly vomit from impressions. My orthodontist would just prepare two sets if impression trays, cause the first one was going to go in the medical waste bin.
Impressions for invisilign (when I did it, about a million years ago) weren't so bad though. Unfortunately invisilign resulted in an open bite for my molars, which I really should go back to an orthodontist to address, but I'd rather not.
AFAIK Align's 3D scanning system is more or less branched from the same Israeli tech that went into the Xbox 360 kinect camera and the iPhone face-ID.
iTero scanners (owned by Align Technology) use parallel confocal imaging via red light lasers. Their newer models also use Multi-Direct Capture techniques.
Kinect used a Light Coding technique, an infrared projector and camera. It was developed by a company called PrimeSense, which was later purchased by Apple.
The difficult part is not the manufacturing, but knowing how to do it properly so you don’t harm the patient.
And yet I read plenty of horror stories of bad orthodontic results. Ask me how I know.
Went to 3 different orthodontist to fix what a bad orthodontist did to me when I was a kid, and each gave me a completely different treatment plan. I feel like being an orthodontist is just eyeballing and patching your way as you go to an acceptable resolution.
Manufacturing them requires a resin printer and a vacuforming setup, but that's still the easy part. It's a whole system with a dental 3D scanner, software for rearranging your mouth, and attachment points that have to be epoxied onto (and later removed from) your teeth by a dentist.
But it’s also something that’s not responsible to shortcut. Shifting teeth around too fast can result in permanent root damage and even loss of teeth. There was a whole cottage industry in the US for a while focused on under cutting Invisalign with a reverse-engineered product, but they often moved on accelerated treatment timelines that caused a not-insignificant amount of harm to patients, and cut corners on intake (DIY at home mold kits) that also contributed to problems. Pretty sure all of the companies doing this are basically dead now.
Also who’s attaching the attachments (I had 13 at first) to the teeth to help the aligners grab hold?