The Effect of Dental Implant Restoration on the Biomechanics of the Temporomandibular Joint in Patients with Posterior Tooth Loss

This study aimed to analyze the impact of dental implant restoration on the biomechanics of the temporomandibular joint (TMJ) in patients with posterior tooth loss. Ten healthy volunteers (Control group) and twenty patients with posterior tooth loss (pre-operative in Pre group, post-operative in Post group) were recruited. Three-dimensional maxillofacial models of the maxilla, mandible, dentition and articular discs were reconstructed. The von Mises stress, contact stress, and tensile stress of the TMJ were analyzed. Before implant restoration, the stresses of the TMJ in the Pre group were considerably higher than those in the Control group, especially on the missing-tooth side. After restoration, the stresses in the Post group decreased significantly, and the stress distribution became essentially symmetrical. Additionally, before restoration, the patients with posterior tooth loss and temporomandibular disorders (TMD) had the highest stresses of the TMJ, followed by those without TMD, and the Control group had the lowest. After restoration, the stress magnitudes in the patients with or without TMD returned to the normal range. In conclusion, dental implant restoration can significantly improve the asymmetric stress distribution of the TMJs, substantially reduce excessive stress caused by tooth loss, and alleviate or eliminate the symptoms related to TMD.