Evaluation of changes of profile and surface after orthognatic surgery is of high significance for the patient. Different techniques have been described, most of them with low impact for the patient. Due to the lack of reliable reference points and levels comparison of pre- and postoperative images were often impossible. The aim of the study was to perform pre- and postoperative three-dimensional surface analysis of the face followed by calculation of slices and section analysis using a non-radiation optical system. Surface analyses of the patients\' faces were done before and six months after surgery using a measuring system with a projection for special light patterns and two CCD cameras. The digitised data were demonstrated as realistic three-dimensional colour pictures and processed in the computer. The evaluation includes pictures resulting from fusion of data, subtraction images and cross-section analysis. A total of 23 patients were evaluated with this technique. Changes were quantified dependant on their locations and compared with the preoperative planning. It was demonstrated that reference points and levels could be defined using an occlusion registration device. The results revealed reproducable statements concerning operation dependent changes of every single point of the surface. With the help of this technique it is possible to analyze acute swelling as well as long term changes of the profile after osteotomies of the jaws and displacement of fragments. Schlagwörter: Optisches Messsystem, Profilometrie, Dysgnathie, Gesichtsweichteile