Craniofacial deformities can occur due to physiological conditions (e.g. cancer or abnormal bone growth) or – far more common – nasty accidents. SIRIM’s craniofacial biomodeling service helps surgeons fix broken skulls by designing bespoke titanium plates for every patient. 

 

THE SKULLERY. 

Titanium plates have been used to patch up broken skulls for decades. Yet there is no one-size fits-all when it comes to these bone plates – like our eyes and fingerprints, our skulls are almost completely unique in shape, as are the shape and size of the holes caused by accidents. Every titanium plate must therefore be individually bent, cut and mangled to fit each wound – a painstaking process usually undertaken by the surgeon himself during surgery and with predictably mixed results.
 
Fortunately, three-dimensional imaging and rapid prototyping technologies now allow man to ‘print’ 3D models of patients’  skulls from CT and MRI cans, so that surgeons can test titanium implants and make the most detailed revisions and corrections to them before the actual surgery takes place.
 
For nearly five years, SIRIM has provided surgeons with such 3D biomodelling services. Every titanium plate produced at the biomodelling centre in Bukit Jalil is delicately knocked, bent and sculpted into shape by hand, allowing surgeons to plan their surgeries with greater precision than ever before. Which is why the patient’s X-ray computed tomography (CT) scans are so important: it gives SIRIM’s biomodelling technicians a geometrical map of the trauma site and helps them build a model of what the skull should look like, although it takes quite a bit of work to go from x-ray to actual biomodel. 
 

Delicate work

Unfortunately, data furnished by a CT scan of a patient with a hole in his head for example will only produce a biomodel of a skull with an identical hole in its head. This is where SIRIM's craniofacial project team essentially has to make educated guesses about what the damaged area to the skull must have looked like before it got smashed. 
 
There are a few of ways of doing this, but the usual approach is to mirror the shape and size of the opposite side of the skull. This is accomplished in a virtual 3D environment by creating a mirror image of the good side of the skull and then positioning it into its corresponding position on the opposite side of the skull. Getting an accurate biomodel depends very much on the skill and experience of the technician that is assigned the task of modelling the patient a new forehead or parietal section. Working on a computer with advanced 3D biomodelling tools, SIRIM technicians use the mirroring technique, craniofacial data and other information to patch up the damaged section of the skull. Once the 3D model is complete, it will be ‘printed’ on SIRIM’s stereolithographic facilities.
 
The team will then have two skulls: a ‘bad’ one showing the damage after the accident, and a ‘good’ one showing the skull as it might have been before the accident. The team will use the good skull as a positive mould to shape the titanium plate. The damaged area is marked out, and a new titanium plate is placed over it and then pushed, cut and banged until it conforms to the shape of the model below. The surgeon in charge of the patient will study the plate and may make some additional  tweaks. When the plate is ready, it is thoroughly cleaned and sanitised at the hospital before it is sent to the operating theatre.
 
Crude as it sounds, there is no other way for doing it. True, some companies in Europe can already make fully-formed bioimplants from digitised craniofacial data with no manual sculpting, but the technology is prohibitively expensive and there is still no guarantee of a perfect fit – CT scan data of broken skulls still has to be extrapolated and technicians still have to extemporise the gaps. In other words, the guesswork is the same. Only the tools are different.
 
Making titanium metal plates is part science, part art, no matter what tools you use to make them. What matters most is the team’s experience and track record. SIRIM has lots of both.
 
 
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