Temporomandibular joint model for asymptomatic and dysfunctional joints

The temporomandibular joints (TMJ) are the only bilateral linked joints in the human body, and are necessary for chewing, swallowing, speech, facial expression, and so on. Computational models can be used to understand the biomechanics of the joint and provide some clinical guidance. Three-dimensional finite element (FE) models of the human mandible and TMJs were developed from reconstructed computed tomography (CT) images of volunteers. The interfaces between the disc and cartilages of the condyle and the temporal bone were bonded together and simulated as gap elements and contact elements, respectively. The results showed that the final configuration and the stress distribution of the TMJ were reasonable when contact elements were simulated on the upper and lower interfaces of the disc, and nonlinear cable elements were used to simulate the disc attachments and mandibular ligaments. Based on these findings, this method was used to analyze the stress distribution of the TMJ under different occlusal loads and the biomechanical effects of typical temporomandibular disorders (TMD), that is, relaxation of discal attachment, disc displacement, and disc perforation. The validated models can be also used for studies of various clinical issues, such as the biomechanical effects of orthognathic surgery, oral and maxillofacial surgery, oral implants, orthodontics, prosthodontics, and so on.