A Clinically Compatible Method for Generating Preoperative Finite Element Models to Simulate Facial Appearance and Movements in Orthognathic Surgery

This study proposes an innovative method for generating patient-specific 3D models of the facial soft tissue, which can be integrated into clinical routine to predict the consequences of orthognathic surgery. This surgery, which impacts both facial aesthetics and functionality, requires precise tools tailored to each patient. To this end, a 3D face model has been developed, integrating anatomically precise bone structures (mandible and maxilla) and soft tissues (skin, fat, and muscles). This reference model is then fitted to each patient's anatomy using a nearly automatic method. This process requires only a manual selection of 34 landmarks to be performed in the clinical setting. The remainder of the patient-specific 3D model generation is fully automated from the patient's CT imaging data. Finally, a proof of concept is presented, featuring Finite Element simulations performed with Ansys APDL software, including orthognathic surgery and then muscle contractions applied to a patient-specific 3D model generated by the nearly automatic method.