Comparative clinical outcomes between stock vs custom temporomandibular total joint replacement systems.

With the evolution of temporomandibular (TMJ) prosthetic total joint replacement, there has been much debate around the advantages of custom over stock prostheses. The aim of this study is to compare the clinical outcomes of a TMJ stock prosthesis (Zimmer-Biomet) to a custom prosthesis (OMX). Clinical data from 139 prosthetic joints placed in 117 patients was retrospectively collected and analysed. All patients were diagnosed with end-stage joint osteoarthritis and were treated by a single surgeon. Minimum follow up was 2 years post-surgery. The cohort was divided into 2 groups, 60 stock prosthetic joints in 54 patients and 79 custom prosthetic joints in 63 patients. This comprised of 110 males and 7 females. The average age at the time of surgery was 53.4yr +/- 12.7yr. There was no statistical difference in pre-operative MIO and pain scores between the two groups. Post-operatively, patients fitted with a custom prosthesis showed statistically significant (P = 0.013) improvement in Maximum Interincisal Opening (MIO) (+6.33 mm vs +2.53 mm) and fewer complications. Following surgery, no difference noted in pain scores and patient satisfaction between the two groups. In experienced hands, both stock and custom TMJ implants work well. However, the added advantages of custom prostheses together with growing access to digital technology is likely to result in custom devices dominating the market in TMJ total joint replacement systems.