3D Bio printing: Great innovation for reconstructive surgeries

According to MedlinePlus, malocclusion may be caused by either disproportionate upper and lower jaws or a difference between the jaw and tooth size. It results in tooth overcrowding or abnormal biting patterns.

How jaws are shaped, and birth defects such as cleft lip and palate are also likely causes. This condition is hereditary, meaning it runs in families. It may also be due to untreated severe facial bone trauma.

Mbuthia’s condition was so severe that it prevented his right side of the jaw from locking normally. This made biting a nightmare for him.

As he grew older, the condition grew worse. It reached a point teeth on the upper dental arch of his right jaw started chewing on the lower gum, an experience he described as a painful ordeal.

“The teeth kept on moving and left a huge gap in between them. It became harder to chew food. It was not easy to move food in the mouth, and every time I ate, large portions would remain stuck in the mouth,” he narrates, adding that he could not handle hard foods like githeri.

Mbuthia’s experiences are not isolated. His is an example of the agony of hundreds of people suffering from the condition across the country.

Doctors, however, say that the condition can be corrected through a complex and highly delicate surgical procedure. Even so, they recommend that correction be made when the patient is still young, but with fully developed jaws.

Correcting Mbuthia’s problem was going to take longer than if he had sought help while younger.

“When I sought expert advice, doctors warned me that it would be a highly risky procedure. The doctor I was seeing told me that the procedure would have been more successful had I done it as a teenager,” he explains.

But Mbuthia was a determined to go through the procedure at whatever cost.

“Doctors advised me to undergo orthognathic surgery, a corrective operation that realigns the jaws, and corrects related skeletal deformities,” he recounts.
The corrective procedure commenced on the first day of December 2017.

Elsewhere, Dr Muthoni Njuguna suffered from familial fibrous dysplasia, a disorder where normal bone and bone marrow are replaced by fibrous tissue, resulting in formation of weaker bones that are prone to expansion.

Throughout her childhood, Muthoni lived with the condition that resulted into a bone deformity, making her jaws appear larger than normal.

“People always stared at me because of my overgrown cheek bones. It was really disturbing as a child and my esteem was damaged. I had to go through a number of surgical procedures to correct the deformity,” Dr Muthoni told DN2.

In 2018, Dr Muthoni underwent the operation. She is still recovering, and is expected to be well by mid this year.

Thanks to 3D printing technology, it is now possible for specialists to correct various deformities of dental arches by developing models for use in the reconstruction process.

In November 2015, Chris Muraguri, then a pharmacy student, was involved in a road accident that left his right leg badly injured.

“The scans didn’t give the full details of the extent of the damage. I was to have surgery, which, instead of the two hours it was supposed to take, it went on for an extra four hours,” he recounts.

He adds: “The plaster on my leg was to be removed after six weeks, but I ended up staying with it for three months. The hospital bill had also soared significantly.”

These two scenarios got him thinking: how could the time and cost of surgery be reduced? What could possibly be done to improve the quality of the outcome of a surgery?

His curiosity to find answers to these nagging questions got him to research while he recovered. He read about 3D Bioprinting technology, which had been in use in the developed world.

Armed with this research, Chris went to the lab and developed a model of his leg, which he presented to his surgeon.

“ My doctor was impressed by the model and even introduced me to other surgeons who worked on my leg. The outcome was very encouraging,” he narrates.

At this point, Muraguri was determined to research further about 3D Bioprinting. For two years, he dedicated his time and resources to the project, working closely with Symon Guthua, the chief consultant and professor of Oral & Maxillofacial Surgery at the University of Nairobi.

He later set up Micrive Infinite, a meditech company that works to reduce the cost and risk of complex surgeries by use of 3D Printing technologies.

“Surgery is an expensive form of treatment. With reduced cost, access to healthcare is increased. My hope is to impact as many lives as possible in line with the Big 4 Agenda,” he notes.

According to Dr Margaret Ndung’u-Mwasha, a Consultant Prosthodontist and Implant Specialist, the technology gives doctors the privilege to operate on the model first before the actual procedure.

“At Micrive Infinite, we provide surgeons with 3D printing services such as atomic models to help them plan for such procedures,” Muraguri explains.

Prof Guthua, who operated on Dr Muthoni says that without this technology, surgeries of this nature would be very difficult to carry out. Precision is crucial considering the delicate nature of the procedure.

So, how does this technology work?

“In this procedure, a patient’s medical scans, such as CT scans, are used to design anatomic models, implants and surgical guides unique to their anatomy. The scans are converted into 3D printed replica models, bone replacement parts or metal prosthetic plates using 3D printing technology,” Muraguri says.

This is primarily the work of maxillofacial surgeons, dentists, orthopaedic surgeons, otolaryngologists, neurosurgeons and plastic surgeons.

He adds: “After a replica of the part of the patient’s mouth has been printed, the model is then hardened and fitted with teeth, with the prosthesis adjusted to fit snugly in place, to make it possible for the patient to chew, swallow and speak.”

These 3D models are created using polythene terephthalate, a special thermoplastic material, and so far, the pair has created more than 100 models, all of which have been used to reconstruct different deformities.

“It takes roughly 36 hours to create and deliver a model, depending on the size. We have participated in all the surgeries that have used 3D printing technology over the last three years,” he says.

This technology has made it possible to reconstruct patients’ faces that have been damaged through gunshot wounds, accidents, tumours or congenital defects of the mouth and face.

“It makes it possible to do pre-surgical planning and practice surgery because doctors can access patient specific anatomically accurate models. Physical models are easier to work with than digital models. Visualising the extent of the problem is easier,” Prof Guthua explains, adding that the patient’s safety is also guaranteed.

Practical approach

Besides, the technology allows doctors to evaluate the patient’s medical history and to advise on the necessary action.

“This technology also allows different professionals to come together in the treatment of the patient,” he adds.

There is nothing better than being able to explain to a patient the extent of a disease, he says, adding that this is a more practical approach.

“They are able to touch and feel the model, which is a confidence booster. They can easily conceptualise treatment,” he observes. Other than that, the new technology is critical in training of upcoming surgeons, he adds.

With this technology in place, however, the cost of surgery depends on the patient’s measurements and the complexity of the model required.

“The bigger the model, the more expensive it becomes,” Muraguri explains. “This technology is a breakthrough for patients who, for some reasons, are unable to service their medical bills immediately.”

He says: “It is possible for a patient to take the models to their health insurer for payment. The insurance company is then able to find out the scope of the condition and to determine extent of coverage.”

According to Muraguri, Micrive has the infrastructure to make this technology that he hopes will tremendously transform the reconstructive surgery landscape in Kenya.

As part of its growth plan, Micrive is operating on a franchise approach, where it designs the models while its franchisees print them remotely.

“We are building the capacity of our franchisees to deliver by providing them with the equipment and skills,” says Muraguri.

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Statistics on the prevalence of malocclusion and other dental deformities in Kenya are scanty

A 2009 study by the Acta Odontological Scandinavica Journal, where 919 schoolchildren aged 13-15 years were examined in Nairobi, found malocclusion standing at 72 per cent.

A similar study in 2012 showed that the occurrence of an anterior maxillary irregularity among children in Nairobi was at 39 per cent. Of the 1,382 children studied, 31 per cent exhibited characteristics of anterior mandibular irregularity.

Malocclusion is thought to be a risk factor in the development of dental caries.

Familial fibrous dysplasia or cherubism, is characterised by unilateral or bilateral change of shape and size in the facial part of the skull, a condition that causes transposition of teeth.

Cherubism is a painless disorder that manifests through enlargement of the upper and lower jaw bones on both sides of the face.

Chubbiness and swelling of the face are the most common symptoms of cherubism. This results from overgrowth of fibrous tissue around the jaw bones.

Like malocclusion, information about occurrence of fibrous dysplasia in Kenya is scarce due to minimal research in the area.

Seven years ago, the World Health Organisation, in a survey “Oral Health Surveys, Basic methods” incorporated the Dental Aesthetic Index (DAI) as one of the criteria for assessing dento-facial anomalies.

According to an article published in the East African Medical Journal in 2012, there is scarcely any study that has been done in Kenya in this sphere.