Study and analysis of facial soft-tissue changes assesment strategies

In the last years the significant improvements done on the 3D scanner devices, both in term of performances and in term of flexibility, has increased their application to many fields. Great benefits have been obtained in the medical context where the new digital techniques for in vivo scanning have made available huge amount of accurate, high resolution anatomical data. Even if most commonly, maxillofacial surgeons rely on clinical examination and photography to document facial anomalies and the results of treatment, this method is highly subjective and unreliable, and it is not suitable for statistical evaluation. Considering that facial analysis would benefit from the development of objective techniques for acquiring facial morphology, some physicians have tried to apply laser light triangulation devices to acquire the 3D representations of external surfaces in a non-invasive, quick, repeatable, and therefore automated way, suitable for statistical evaluation. However the automatic capture of anatomic data in vivo is often affected by artifacts and errors caused by difficulties in defining protocols to employ these information. Long post-processing time and consistency problems, during the merging process of all the data reached during the face acquisition still limit significantly the wide application of these systems in the present medical procedures. Starting from experiences developed on 3D scanners this paper wants to analyze some of the methods currently proposed by the technical literature (3D morphometric) in order to evaluate their applicability, reliability, and informative value. Working on a case-study the research work will identify strengths and critical points of the different methodologies, as the starting step for the definition of a standardized procedure for facial morphology evaluation that could give to the physicians useful information for the diagnosis of medical