Use of prototyping in the preoperative planning of patients with head and neck tumors

BACKGROUND: Prototyping is defined as the fabrication of physical models of human anatomy, obtained from medical data (computadorized tomography). Reconstruction is obtained in order to achieve a tridimensional model of the desired objects. Solid models are built through the sedimentation of successive layers of the utilized material. OBJECTIVE: To demonstrate the results of a prospective, randomized, doble-blinded study seeking the evaluation of the efficacy of prototyping in medical planning, before and after operative techniques are applied, in head and neck tumor disorders. MATERIAL AND METHODS: 37 cases compose this study. The first randomized group (A group) was submitted to microsurgical reconstruction with prototyping after mandibulectomy had been performed. The second randomized group (B group), presenting the same tumor features, was submitted to the same kind of surgery in function of the tumor presentation, in exception to the use of the prototyping. A few variables were evaluated: time of the plate and screws exposure, flap size, screw choice, knowledge of tumor tridimensionally and reduction of costs and anesthetics as well as the final aesthetic result. Prototypes were manufactured at CenPRA (Centro de Pesquisa Renato Archer – Ministério de Ciência e Tecnologia – Campinas/ SP). RESULTS: The A Group presented reduced surgical median time, taking into consideration mandibulectomy and bone flap harvesting (43.7 minutes vs. 127.7 minutes, respectively; p = 0.001), smaller flap size (2.1 cm vs. 8.7 cm, respectively) and diminished time with plate modeling and screw adjustments (30.4 minutes vs. 86.6 minutes, respectively; p = 0.001), taking account the B group. With surgical time reduction, we had a reduction of anesthetics and costs. The aesthetic results were better in the prototyped group...