STEREOPHOTOGRAMMETRIC ANALYSIS OF THE HUMAN FACE: A TOOL FOR MODERN MORPHOLOGISTS

The introduction of new technologies has provided, in the last years, a significant contribution to anthropometry. In this context, facial anthropometry has greatly benefited from optical instruments such as laser scanners and stereophotogrammetry. The latter technique has proven to be accurate, repeatable and fast; therefore, taking into consideration its non-invasive nature, it has been increasingly applied to medicine, due to the relevant support that anthropometry can provide to this field. A facial anthropometric assessment can provide reliable morphometric details about the presence of deformities and peculiar features connected to underlying pathological conditions, not always easily recognizable. In the case of certain neurologic diseases, it can also provide new insights about the genotype/phenotype correlation taking the close relationship between facial and cerebral development into consideration. Furthermore, the three-dimensional morphometric evaluation of the face can reveal objective parameters useful for the planning and assessment of maxillo-facial and dental treatments, thus facilitating the clinical decisions and increasing the patients’ compliance. The facial morphometric evaluations presented in the current thesis were performed through the VECTRA M3 3D stereophotogrammetric system (Canfield Scientific, Fairfield, NJ, USA). All the patients and control subjects involved were marked with a set of facial landmarks (adapted according to the different study purposes), before the acquisitions. Once the three-dimensional models were obtained, they were elaborated through the software of the stereophotogrammetric system. Data were analysed through different statistical techniques, according to the type of study executed. The morphometric evaluations were divided in two groups: facial morphometric analyses performed through a landmark-based approach and through a surface- based approach. The first group included the studies: 1) “The face of adult patients affected by Dravet Syndrome: a 3D stereophotogrammetric preliminary assessment”, 2) “3D Craniofacial morphometric analysis of GLUT-1 DS patients” and 3) “Stereophotogrammetric analysis of a case of holoprosencephaly”. The second group included the studies: 4) “3D stereophotogrammetric assessment of labial symmetry in a girl treated for a lymphatic malformation” and 5) “Facial reanimation assessment performed through 3D-3D superimposition: a new method”. 7 For both assessed syndromes, study 1 and 2 allowed the individuation of facial features common among the patients, whose recognition can have a role in the diagnosis of the disease, both in children (study 2) and in adult cases (study 1). Study 3 allowed the identification of the presence of dysmorphic facial features in a girl affected by holoprosencephaly with an apparently normal aspect, thus sustaining the potential of the 3D stereophotogrammetric facial analysis in the morphometric characterisation of the face. Study 4 and 5 showed the usefulness of this technique for performing an objective surgical follow-up and final evaluation of maxillo-facial treatments, helping clinicians in their decisions and motivating the patients. In conclusion, all the studies sustained the usefulness, for medical purposes, of an anthropometric assessment of the human face, performed through a three-dimensional stereophotogrammetric analysis. Moreover, they highlighted its applicability to different categories of patients, including children and people with intellectual disability; thus again justifying the increasing diffusion of stereophotogrammetry in clinical and research centres.