SIMS Hospital, Vadapalani a reputed multi-speciality hospital in Chennai, has successfully performed rare surgeries of total jaw joint replacement using 3D-printed as well as readymade jaw joints for three patients, recently. Though surgeries for the replacement of hip and knee joints have become common, the ones for the replacement of jaw joints and the use of 3D printed custom-made joints are new.

Explaining the uniqueness of the procedure, Dr. K. Sridhar, Director, Institute of Craniofacial, Aesthetic & Plastic Surgery, SIMS Hospital, said, “We have performed total jaw joint replacement for three different patients. In one patient, who had zero mouth opening following a jaw surgery done elsewhere, the damaged jaw bone part was replaced with an artificial part made of titanium metal.

The same was done for the second patient who had complete ‘ankylosis’ (immobile joint) of temporomandibular joint (TM joint), which acts like a sliding hinge, connecting the jawbone to the skull. This patient also had complaints of sleep apnoea (snoring and sleep disorder due to less oxygenation) and hypoplasia of jaw bone (smaller than normal jaw bone). For this patient, first, the jaw bone was lengthened with distraction and later total joint replacement was performed.

The third patient had a bone tumour, for which the entire one half of the jaw, the TM joint and the adjoining facial bones were removed about 20 years ago. This patient required a custom made jaw joint for replacement. Since no bone was available to fix the joint, the total jaw joint was replaced with artificial jaws made of titanium and polyethene using 3D printing technology. Since this patient required teeth on one half we also took leg bone and did microsurgery and put in a dental implant also at the same time.”

All the patients now have very good mouth opening. The two patients who were not able to open their mouths at all are on solid food after many years. The third patient with a custom made joint is waiting for the fixing of the teeth on the implant.

Talking about the necessity of jaw joint replacement, Dr. Sridhar said, “Patients who have problems with opening of mouth (Trismus) due to infection, arthritis or trauma, struggle to chew their food. In extreme cases, the patients can hardly achieve 2-3 mm of mouth opening. We call the condition of immobile joint as ‘ankylosis. Those who have ankylosis will not be able to take real solid food, and will be forced to live their lives only with a soft or semi-solid diet.”

Usually, the treatment for ankylosis involves the creation of a gap by cutting the fused joint and tissues (like muscle, cartilage, or silicone) to prevent fusing again. But, recurrence and failure are very common. In the case of cancer, the adjoining bone may be removed leaving behind a large gap. The reconstruction for it is done by transferring a bone from leg to jaw with micro-surgery. This is possible if a joint is present. If the joint is also removed, then there is a need to create a new joint.