title: Facegram - Objective quantitative analysis in facial reconstructive surgery.
abstract: Evaluation of effectiveness in reconstructive plastic surgery has become an increasingly important asset in comparing and choosing the most suitable medical procedure to handle facial disfigurement. Unfortunately, traditional methods to assess the results of surgical interventions are mostly qualitative and lack information about movement dynamics. Along with this, the few existing methodologies tailored to objectively quantify surgery results are not practical in the medical field due to constraints in terms of cost, complexity and poor suitability to clinical environment. These limitations enforce an urgent need for the creation of a new system to quantify facial movement and allow for an easy interpretation by medical experts. With this in mind, we present here a novel method capable of quantitatively and objectively assess complex facial movements, using a set of morphological, static and dynamic measurements. For this purpose, RGB-D cameras are used to acquire both color and depth images, and a modified block matching algorithm, combining depth and color information, was developed to track the position of anatomical landmarks of interest. The algorithms are integrated into a user-friendly graphical interface and the analysis outcomes are organized into an innovative medical tool, named facegram. This system was developed in close collaboration with plastic surgeons and the methods were validated using control subjects and patients with facial paralysis. The system was shown to provide useful and detailed quantitative information (static and dynamic) making it an appropriate solution for objective quantitative characterization of facial movement in a clinical environment.
authors.affiliation: Faculdade de Engenharia, Universidade do Porto, Portugal; i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Gerós
authors.affiliation: Department of Plastic, Reconstructive and Maxillo-Facial Surgery, and Burn Unit of Hospital São João, Medical School, Porto, Portugal.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Horta
authors.affiliation: i3S - Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Portugal; INEB - Instituto de Engenharia Biomédica, Universidade do Porto, Portugal. Electronic address: pauloaguiar@ineb.up.pt.
authors.forename: Paulo
authors.initials: P
authors.lastname: Aguiar
mesh_terms: D000465:Algorithms; D005145:Face / Q000033:anatomy & histology* / Q000601:surgery*; D005158:Facial Paralysis; D006801:Humans; D009068:Movement; D019651:Plastic Surgery Procedures
keywords: 3D spatiotemporal analysis; Facegram; Facial measurements; RGB-D cameras; Reconstructive plastic surgery; Tracking