3D modelling and addiitive manufacturing can create pre-operative models
It was an impressive collaborative effort. A team from the Centre for Rapid Prototyping and Manufacturing (CRPM) at Central University of Technology, Free State (CUT) in Bloemfontein and specialists from the University of Pretoria and Mediclinic Kloof worked together to undertake a ground-breaking operation on a teenage girl. Ennica Mahkge, 19, was born without a nose and nasal passages and had an opening in her windpipe that allowed her to breathe. Unfortunately, she suffered from regular infections and had miserable life.
“To allow Mahkge to breathe, an opening in her windpipe was created at birth,” says Dr JH van den Heever, CUT Extraordinary Professor. “This increased her tendency to develop upper respiratory tract infections and this then caused a chronic infection. The latter resulted in the need to do a nose replacement operation where her nasal passages were created by moving her jaw forward and down. This operation was designed to create the space she needed for the new nasal passages.”
The team from CRPM played a vital role in the reconstructive surgery through the use of Additive Manufacturing (AM) technology, also known as 3D printing. They printed two models of Mahkge’s skull so that the team of doctors could carry out pre-operative planning and simulate the operation.
“This was a first for South Africa and there are only 50 other documented cases in the world so there was no absolute protocol in place for the surgeons to draw from,” says Gerrie Booysen, Director of CRPM. “These pre-operative models were essential to the process, empowering the doctors in their planning and their simulation of the operation down to the finest detail.”
Through close examination of the pre-operative models, the surgeons were able to determine where the upper jaw needed to be cut in order to place it in the correct position and to prepare the titanium plates that were to be used to reconstruct it. This meant that operating time was considerably reduced which cut down the chances of complications that can arise from a prolonged operation, such as infection or excessive blood loss.
“All of the goals we set out for ourselves in terms of the surgery were met,” said Dr Herman Kluge, Maxillo-Facial and Oral surgeon. “All the complications that we tried to avoid were not part of the process so, for us, it is a huge success.”
The CRPM used data from the patient’s CT scan along with highly specialised software to segment the bony features from the soft tissue and thereby prepare a 3D computer model. This 3D model of Mahkge’s skull and upper jaw clearly showed the affected area and was loaded onto a 3D printing machine so it could be manufactured from plastic powder and laser sintering processes.
“The models were created down to the last, perfect detail so as to ensure that the surgeons had the most accurate and realistic references possible,” says Booysen. “As a result of this collaboration, a young girl can breathe through her nose for the first time and she can do things that the rest of us have taken for granted — go to school, make friends, go out to dinner.”
The innovative surgery took Mahkge from a world where she was only one of about 50 people in the world born with this condition to one where she could finally breathe for the first time. So, history was made at Mediclinic Kloof when the team of specialists gave her a new nose and so far her progress has been excellent.
“She adapted to her new face within two weeks and was so motivated and determined,” says Van den Heever. “It is a real privilege to have been part of her journey towards a normal life and we will continue our involvement in solutions and procedures that bring hope to those who need it the most.”
Changing lives, changing the face of AM
The recent award by the South African Research Chairs Initiative (SARChI) to Central University of Technology (CUT), Free State grants them a five-year Research Chair in medical product development through Additive Manufacturing (AM). It is a significant achievement that places the institution onto the world map and taps into the global trend to develop AM and use it to further transformation within the medical space.
The award of the Chair should not come as a surprise as CUT and the Centre for Rapid Prototyping and Manufacturing (CRPM) have been doing some impressive work. “AM has the potential to transform lives and CUT is driving this change for the betterment of ordinary people,” says Gerrie Booysen, Director of CRPM. “One of our most noteworthy achievements was when Dr Cules van den Heever, an extraordinary professor at CUT, collaborated with CRPM to change the lives of two patients whose mandible implants were moulded with the use of 3D printing at the Bloemfontein campus. The procedure, which went extremely well, made medical history and was an impressive achievement overall.”
On 23 July 2014, doctors Van den Heever, Walleed Ikram (head of Kimberley Hospital Dental Unit) Kobus Hoek (a maxillofacial surgeon), Philip Johnsson and Riaan Liebenberg installed titanium implants into the jaws of two patients who had severe facial disfigurements. These implants had been printed layer-by-layer using the AM process and the equipment at the CRPM to ensure that they were perfectly moulded to the individual jawlines of each patient.
The two people who received the titanium implants had lost significant portions of their jawlines to cancer. As a result, their quality of life had been seriously impacted and they were struggling with day-to-day activities. The first patient was a 31-year old man who had suffered from tumour deformities along his lower jawbone. The second patient was a 20-year old man who needed a replacement implant after his original one broke.
“Cancer is a terrible disease that affects so many people and with more than 500 cases of head and neck cancer diagnosed every year, these cancers can really impact on quality of life,” says Van den Heever. “Thanks to this collaboration with CRPM, we were able to fix the facial contours and restore normal functioning.”
The two jaws were modelled using Materialise Mimic, 3-matic and Magics software and printed with a titanium powder through a laser sintering process. Thanks to the precise nature of the process and the high level of technological proficiency, the two jaws were exact matches for their recipients. They had been custom built and designed, but the amount of time spent on the process was reduced significantly.
“Not only did this procedure change the way in which the medical community views 3D printing, but it also cost much less than traditional jaw implant surgery,” says Dr JH van den Heever, CUT Extraordinary Professor. “Surgery time was reduced, only the right amount of titanium was used and the jaws fit precisely, making it far easier for the specialists to do their work.”
Impressive and exciting, AM has incredible potential on the medical frontier. Now, with the Research Chair enabling five years of further research and innovation, the CRPM is set to break more boundaries and find innovative new ways of helping others in the medical arena.