The Effects of Unilateral Alloplastic Temporomandibular Joint Replacement on the Opposite-Side Natural Joint: A Finite-Element Analysis

Purpose: The purpose of this study was to evaluate the stress distribution on the temporomandibular joint (TMJ) prosthesis and contralateral natural TMJ with finite-element analysis. Materials and Methods: A TMJ implant was used to create a 3-dimensional model with a computer. This model was integrated with a mandible model created with a computer by use of computed tomography images, similar to a real TMJ replacement procedure. Masticatory loads were applied to the model. The loads transmitted to the TMJ prosthesis and contralateral healthy joint were evaluated by means of finite-element analysis. Results: In the model without the TMJ prosthesis, maximum von Mises stress was 252.697 N/mm(2) at the condyle and 5.418 N/mm(2) at the disc. In the model with the unilateral TMJ prosthesis, maximum stress at the joint prosthesis was 792.681 N/mm(2). In the contralateral natural joint, maximum stress was 268.908 N/mm2 at the condyle and 8.357 N/mm(2) at the disc. Conclusions: In the TMJ model with the unilateral total TMJ prosthesis, increased stress values were observed at the disc and condyle of the contralateral natural TMJ. (C) 2017 American Association of Oral and Maxillofacial Surgeons