New challenges for reverse engineering in facial treatments: How can the new 3D non-invasive surface measures support diagnoses and cures?

Reverse engineering can give new challenges for diagnosis and facial treatments, offering 3D measurements, impossible to obtain only few years ago, in terms of richness of information, precision, accuracy and reliability. In this paper the main aspects and methods for skull and facial scanning and measurement are analyzed, considering volumetric methods (CT, MRI) and surface approaches (laser scanning, structured light and photogrammetry). These latter are particularly interesting because they avoid exposing the patient to ionising radiation and to any biological risk. The EU directives in fact require minimisation of radiographic exposure, that will be in the near future justified only for real diseases, but not for aesthetic treatments and surgery, orthodontics, and malocclusions. Photogrammetry is very promising for the digital reconstruction of human faces; it seems to offer the best compromise with respect to realistic and accurate reproduction, processing time, simplicity and cost of equipment. New software platforms have been developed to integrate the information acquired using different tools: photogrammetry, CT/Cone beam computerized tomography (CBCT), laser scans of dental cast study models. In this way a powerful multi-user database system can be realised to track the patient's imaging history throughout the treatment cycle and to forecast the growth and the results of the treatments.