In the presented paper, we propose to improve the state-of-the-art approach for Cranio-Maxillofacial (CMF) soft tissue simulation by considering a new image-based meshing approach that accurately models the interface between different tissue types. The proposed approach has been initially evaluated on soft tissue deformations of four patients undergoing CMF surgery using post-operative CT scans. The results indicate improved prediction and robustness of the surgical planning outcome when compared to the state-of-the-art method while decreasing the simulation time.