[The effects of a total TMJ endoprosthesis on the contralateral condyle]

Area of Science:

• Oral and Maxillofacial Surgery
• Biomechanical Engineering
• Orthodontics

Context:

• Post-traumatic jaw deformation necessitates advanced reconstructive techniques.
• Unilateral total temporomandibular joint (TMJ) replacement is a viable option for restoring mandibular function.
• Understanding the biomechanical interplay between prosthesis and native joint is crucial for optimizing outcomes.

Purpose:

• To correlate prosthesis translation magnitude with native joint movement and contralateral condylar process volume changes after unilateral TMJ replacement.
• To investigate the relationship between mandibular kinematics, endoprosthesis function, and native joint remodeling.
• To identify factors influencing translational movement of TMJ endoprostheses.

Summary:

• A study of 16 patients with unilateral TMJ replacement revealed an average 8.5% decrease in native condylar process volume.
• Postoperative analysis showed significant deviations in native joint movement and marked translational movement of the TMJ endoprosthesis.
• Correlation analysis indicated a negative relationship between native and endoprosthesis movement amplitudes and a complex relationship between condylar volume change and joint/prosthesis movement.

Impact:

• Electronic axiography demonstrated restoration of some translational movements post-surgery, even with altered muscle attachments.
• TMJ endoprosthesis translational movement is significantly influenced by fossa component design and lateral stoppers.
• Unilateral TMJ reconstruction impacts native joint volume, directly related to native joint movement and inversely to endoprosthesis movement amplitude.