SummaryIn craniofacial surgery it is not easy to predict the shape of the postoperative face, as muscular changes resulting from the surgery cannot be found by a simple way. Three‐dimensional (3D) computer simulation of craniofacial surgery can be extremely useful to foresee the surgical outcome. Many authors proposed computer systems for craniofacial surgical planning based on computed tomographic (CT) images. A number of methods to achieve the prediction of soft tissue behaviour have been proposed from computer‐aided surgical planning system integrating anatomy‐based 3D finite element tissue model to methods for computation of soft‐tissue deformation in craniofacial surgery directly from CT images without any intermediate geometric model. We present a review of present techniques on the use of imaging in the presurgical planning of facial surgery and reconstruction. The entire workflow of image acquisition, tissue segmentation, tissue classification, surgical planning, soft tissue displacement computer simulation and visualization is outlined and different cases of real maxillofacial surgery are illustrated.

Volume rendering techniques are particularly useful for the visualization of echographic data which appear noisy, irregular and fuzzy. Data were acquired by means of an annular transducer which rotates around its axis with increments of 3.6 degrees allowing the acquisition of 50 ECG-gated 2-D echography images. The 2-D images acquired in polar coordinates were remapped over a cartesian grid to produce a cube of data. A transfer function that allows the mapping of the 3-D echo data into colour and opacity visual parameters to enhance the regions of interest has been considered. A suitable shading algorithm allows the data to be viewed 3-dimensionally by means of a simple illumination technique. The final 2-D image is obtained by means of a back to front ray casting algorithm