Simulation of Facial Soft Tissue in Orthognathic Surgery

Orthognathic surgery consists of rebalancing the position of the jaws, taking into account functional criteria (tooth engagement, tooth/lip ratio, breathing, etc.) and aesthetic criteria. It has become much more accurate in recent years thanks to the advent of osteosynthesis plates and the contribution of three-dimensional imaging. Three-dimensional imaging makes it possible to simulate fairly accurately the surgical procedures and bone displacements required. However, the effect of these bone displacements on the soft tissues (skin, subcutaneous tissue, muscles) does not make it possible, with today's digital tools, to simulate the final aesthetic result and in particular to anticipate the sometimes significant postoperative changes to the face. Many patients are worried about these post-operative morphological changes and would like to have a precise idea of how they will look after surgery. Being able to offer them, before surgery, a visual solution simulating the final aesthetic appearance would be essential in this respect. The aim of the study is to validate the predictions provided by the digital face model on a series of patients scheduled for orthognathic surgery by comparing the simulation of the morphological result of the operation, provided by our algorithm (SPOC), with the actual result assessed on a scan taken 6 months after the operation.