The dependent typically goes on the Y axis. That said, he does seem to be going at it in a non-intuitive manner (for me, anyway). The cause and effect seem backwards. He's optimizing for a customization level even though that's clearly the cause for happiness, not the other way around.
Not disputing his point, but I agree, the graph is confusing.
I think what he's saying is that an artificial balance hides the actual biases. Kind of like how cooking the books doesn't mean you didn't cheat on your taxes, you just made the numbers work.
That's the definition of p[H]. The definition of the "real" pH is the -log of H+ activity. H+ activity is the concentration of H+ * a coefficient. In practice, the coefficient is considered to be 1, however there are cases (such as extreme concentrations) when that approximation isn't valid.
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.
I wouldn't call it typical, but I didn't have any fillings until I was 33. Everyone's biology is a bit different — salivary flow, composition, etc. Probably the most important thing that you mentioned is the limited sugar intake. Carbs => acid => cavities.
Keep in mind that these things tend to deteriorate as we age, so you might not be able to get away with rarely brushing forever.
This headline is overly sensational — this treatment does not apply for what most people consider cavities (i.e. caries, bacterial decay). It only applies for the very early stage caries process where enamel is just beginning to become demineralized.
Tooth enamel is essentially a matrix that is hardened by mineralization. Caries initially demineralize the enamel, but as they progress they destroy the enamel as well. Once that enamel is gone, there is nothing left to mineralize. You can throw as much calcium, phosphate, electricity, etc at it and you won’t end up with any more enamel. The decay has to be removed and filled with something.
This proposed treatment only works for the very initial stages of demineralization, which are referred to as white spot lesions, since demineralization causes the enamel to become opaque. The current conservative treatment for white spot lesions is to be judicious with cleaning and possibly apply some additional fluoride, as the tooth simply needs to be remineralized. The researchers are claiming to be able to accelerate that remineralization, which is great, but is very, very far from saying that patients won't need fillings.
> Instead of filling the root canal with artificial materials that may pose bio-compatibility problems
Gutta-percha[1] is what is traditionally used to fill the empty canals. It is used because of its bio-compatibility and inertness. The most common complication of a root canal procedure is inadequate cleaning of the canals and related tissues, not bad apical sealing.
I forget where I learned this from, but the astronauts were also very likely to be unconscious very soon after the break up of the shuttle. They died when they hit the water, but they probably weren't conscious. Not that that makes it any better.
That's exactly why depression is so hard to shake. You beat yourself up repeatedly without even knowing it and wonder why the heck you can't just snap out of it.
Sometimes I wonder how my counselor deals with telling me the same thing again and again for months. And then I sign her check :)
Seems like this is a book worth checking out, thanks!