Machining an anatomical fit based on medical CT-Data

So this project is a bit out there, wasn’t sure I was gonna share it but thought that maybe someone more creative/artsy than me get some inspiration for some cool art or something based on this type of data.

I had a medical cone beam CT done earlier this year to look at my sinuses (not a serious medical condition) and realized just last week that I had this great image data to do something cool with. I had my hospital send over the CT-data and used 3DSlicer (open source software developed by NIH, there are plenty of tutorials online) to open it. I had this idea of making a wooden hat with an anatomically perfect fit for my head, a personalized hat if you will. Imagine my disappointment when I realized they only imaged the front part of my head…

I suppose I should be grateful they didn’t blast my entire brain with ionizing radiation but still… a high resolution scan of my entire head would probably have been useful for a bunch of projects. I wanted to do something with the data since I went through the trouble of getting the hospital to send it over. I thought that I would use something based on the bone tissue in the scan since it is fairly easy to segment due to it’s higher attenuation of xrays compared to soft tissue. So I decided I would try and machine a retainer, the plastic bit people use to keep their teeth in place after adjustment with braces. So I segmented out the bone tissue in the scan then removed everything except for the teeth in my upper jaw, made an offset of 0.75 mm to have some clearance for the retainer, hollowed it and cut off the top part of it.

Here is a creepy render of the polycarbonate retainer/grill on my skull.

I set up the toolpaths in Fusion 360 and added 3 cylinders to hold the part in place for a 2-sided machining job. I used 4 mm dowel pins to relocate the part after flipping it.

I machined the part from polycarbonate using a 3 mm flat end mill, 2.5 mm ball end mill and finished with a 1 mm ball end mill. I should probably have added something under the part before machining the second side as there was some significant deflection of the stock with only the 3 cylinders holding it when going over with the ball end mills.

Haha, here it is. Before and after pictures. There really is no way to look good on these…

I have never been self conscious of my teeth but seeing this retainer, its not close to symmetric haha… But the fit is perfect! A bit surprising since I added 0.75 mm clearance based on the CT, but I can’t move it at all. In hindsight I should have made the part taller, its pretty small.

I think you could make some pretty cool organic art stuff with this type of image data. I might make a Halloween mask and do a boolean subtraction of the backside of it using the CT data for a perfect fit in the future…

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That’s OK, just machine a new head :wink:

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Haha, that would solve a great many things!

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You really must try to create a double-sided (two-faced? :smiley: ) object for Halloween, and manipulate the face on one of them.

I can see it rotating on your shoulders. :smiley:

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That is fantastic. I never would have thought of this. You can make the perfect fitting covid-19 mask. Carve your face and see what you look like in different glasses. Make mask molds to scare your friends. Make a cast for your nose after you scare the crap out of somebody and they punch you in the nose.

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Haha, I’ll see what I can do! @CrookedWoodTex

Thanks for the enthusiasm! @Tominator I need to choose among these projects with care. This one was definitely frowned upon by my partner. Not sure what reaction to expect if she finds a carved copy of my face haha…