Improving quality of life through biomechanics, surgery and industry collaboration

A highly personalised, 3D-printed titanium jaw joint  has been implanted in over 260 patients to treat a range of conditions, including osteoarthritis, bone tumour resection, trauma and congenital abnormalities. It is providing restored, pain-free function and greater quality of life, with many more people set to benefit. MAXONIQ is currently working on FDA (US) and MDR (Europe) approvals for the TMJ Arthrojaw, which should allow exporting from 2023.

This first-of-its-kind device was created through a collaboration between Australian-owned MAXONIQ, the University of Melbourne and industry partners. It brings together biomechanics research, surgical expertise, and cutting-edge 3D-printing technology to provide a safe, efficient and cost-effective solution for complex conditions of the jaw, which may not be treatable otherwise.

The ArthroJaw is also advancing the field of personalised surgeries. Established for the device, MAXONIQ, now has a growing portfolio of world-class custom oral and facial implants for other conditions, with 10 trademarks and over 25 patents and patents pending. Its goal is to be the world leader in custom-made surgical products and devices that will revolutionise oral and maxillofacial surgery.

Associate Professor David Ackland, Australian Research Council (ARC) Future Fellow and Deputy Director of the ARC Centre for Medical Implant Technologies in the Department of Biomedical Engineering at the University of Melbourne, says:

“The ArthroJaw is one of a kind. But it’s not just the implant, it’s the seamless pipeline that has been created. From taking data from medical scans through to a personalised device ready for implantation – from testing, fabrication and sterilization, and critically, navigating the regulatory environment, and carrying out clinical trials. We have an entirely new capacity to develop customised implantable components for a wide range of bone and joint problems. The company is now at a position where they can grow and develop other products.”

For decades, patients needing a new TMJ – usually as a consequence of osteoarthritis or trauma – have had limited options, and would typically receive an off-the-shelf prosthesis manufactured in the US, which requires significant, invasive surgery and presents risk of nerve damage due to limitations in the underlying implant shape and fixation.

A TMJ implant that can be customised to the patient, affordable and quick to make would allow thousands more patients to receive treatment for complex conditions, reducing pain and increasing their quality of life.

The ArthroJaw is based on years of research by Dr Dimitroulis and a team of engineers from the University’s Department of Mechanical Engineering, led by Associate Professor David Ackland, in collaboration with industry.

“The challenge was to create realistic, almost life-like computer models of bones and joints that really represented a patient and their physiological jaw loading. We needed to come up with techniques to take medical images through to a working 3D computer model, with muscles that generate force and load and that we can drive with motion, to be a reasonable approximation of the real-world jaw, and allow assessment of implant functional performance,” says Associate Professor Ackland.

Crucially, biomechanical research came together with surgical expertise – where engineers worked with clinicians, including a maxillofacial surgeon – along with experts in manufacturing, 3D printing, prototyping and sterilizing. BresMedical, for example, helped them adopt additive manufacturing – layering rather than cutting away – as a simpler, more cost effective and efficient way to manufacture.

“It wasn’t just a design engineer. The entire process required a strong understanding of the clinical need, musculoskeletal biomechanics, medical device regulation, and local and international manufacturing landscape. A lot of things had to happen to take the idea through to a product that could safely be implanted into a patient."

The academic underpinning has been crucial for the company and for advancing research more broadly. The validation, assessment, and academic outputs provide credibility for MAXONIQ, while also supporting further research work in jaw and dental biomechanics beyond the ArthroJaw, through research grants, local and international conference presentations and peer-review papers.

The TMJ began with the vision of Dr Dimitroulis to create a new device that would solve the issues associated with existing implants.

In 2012 he approached the University’s Department of Biomedical Engineering to see if they could help him bring it to fruition. Impressed by the innovation, they jumped at the chance to take part and close collaboration began.

The University played a significant role in the early stages of development, first coming up with the concept of the temporomandibular joint replacement. Then creating a generic computer model of the jaw, with all surrounding muscles and bones, as a basis for the design and preliminary modelling and testing.

The next three years saw Associate Professor Ackland and his team – including engineering students – work on developing the computer model and engineering the new jaw prosthesis, working with Dr Dimitroulis to ensure it would meet all the key requirements.

With little funding to begin, as things progressed the team was able to attract research grants and publish work that helped them get to a design they were happy with, and create a prototype.

The prototype was then put into a cadaver for rigorous biomechanical testing and modeling. And they performed a virtual implantation surgery, and simulations to assess the functional performance of the device.

By 2015 they had fabricated a biocompatible titanium joint that could be fitted to the anatomy of each subject. It was comfortable, cost less than existing older technologies to fabricate, and quick to produce – up to two weeks from design to implantation. They had also designed out one of the biggest problems with the old-style replacement joints – the risk of damage to the mandibular nerve.

Approved in 2015 for clinical use in Australia, they completed the first implant in a young adult patient, Richard Stratton. Then in 2016, Dr Dimitroulis established MAXONIQ (formerly OMX Solutions) to commercialise the TMJ Total Joint Replacement System which was also listed on the ARTG prosthesis schedule of medical devices in 2016. Soon after, MAXONIQ began developing other custom oral facial implants and surgical support products.

Refining the design continues. Currently, the team is measuring high accuracy motion data in prosthesis recipients to improve range of motion and assess alternative materials that could have better loading capacity, be easier to install, more lightweight and stronger.