The making of a bespoke prosthetic jaw from a patient's existing medical data is one of those things that seems both easy and obvious on the surface, but one which is frought with implementation issues when you get right down to it.
Here, we see the LayerWise jaw, a prosthetic replacement jaw made from titanium, and coated with a bioceramic, designed to exactly match the contours of the original jaw it is replacing. In the image you can clearly see the original jawbone with the new prosthetic superimposed on it in blue. The skull image was created from a computational topology scan of the patient herself, using DICOM (Digital Imaging and COMmunications in medicine) standards for data interoperability between devices. It being shown here is of course more than just decoration; the arrangement of the existing bones in the patient's body as taken from this 3D scan data, was used directly as CAD input data to create a jaw that as exactly as possible matched the contours of the old one. This matching was performed right down to dimples increasing the surface area, cavities promoting muscle attachment, and sleeves to lead mandible nerves.
In short, it was designed to fit as tightly into the body as possible. There is even an attachment built into the new 'bone' for the later adding of prosthetic teeth, restoring full function. The idea being that the prosthetic would respond to the body's commands, and allow talking and even chewing of food, with as minimal a learning curve as possible, encouraging the body's musculature to adhere to it just as with the old structure. Of course, much of this work was perfored manually on the data by human operators, as this was the prototype for its kind. However with the confirmed success of the first model in meeting - and even exceeding - expectations, much of the placement data both gathered and confirmed by this prosthetic, will be used to look at ways of automating the process of designing a jaw to fit.
This would remove much of the manpower, and thus much of the cost. Creating the device is simplicity itself, and any 3D printer that can work with powdered titanium and heat, will do the job. Thuis one was created by a process of powdered titanium 'ink' fused together in layers with a heat laser, thus removing the need for any glue. It is a solid piece of titanium, and took just four hours to print, the same length of time it took to implant. The patient was able to use it to utter a few basic words within 24 hours.
So, whilst the LayerWise jaw was a groundbreaking achievement, further jaws will be easier, and even cheaper to assemble. The gruntwork will steadilly be taken out of hte process, and in the end the patient is left with a jaw that perfectly fits them - and only them. It cannot be used for anyone else, and was essentially created by that CT scan they had done, plus a technician's tweaking for individual improvements. For example, if someone wished a narrower jawbone than they started out with, or a wider one then a technician would have to make adjustments to the basic design; however all the important elements such as the hinge, muscle and nerve positions, remain aligned to perfection. We know this, because it has already been done.
Further ReadingLarge Image Display: Teeth Designed for Prosthetic Jaws
Large Image Display: Connecting Teeth to Artificial Bone
ReferencesForm Fitting Prosthetics Using DICOM Data