The authors have investigated the clinical role of the soft tissues and of their influence in the planning phase of the orthognathic surgery, with the purpose to emphasize their capital influence in the face armony. Most of the patients really ask for an aesthetic result, that is in a tight relation with the correct prediction of the morphological changes of the soft tissues. The aesthetics excite nowadays the research, especially in all the surgical fields, and so the orthognatic surgery is more than ever from the soft tissues influenced. Subsequently the authors have investigated the principal indications to the bimaxillary surgery and have suggested a personal diagnostic-therapeutic protocol for a correct and opportune evaluation of the soft tissues relations. Finally the authors have described the whole prediction phase and have shown as the maxillary bones influence the whole facial skelett, and as frequently the chin correction and the rhinoplasty are necessary for a better result in the time.