Virtual Surgical Planning and Three-Dimensional Printed Guide for Soft Tissue Correction in Facial Asymmetry

Fat grafting has become a well-accepted surgical modality to correct soft tissue facial defects and asymmetries with overall good results. Several techniques have been reported over the last few years to assist in improving accurate evaluation of facial defects and in the preoperative planning of the reconstruction. Such techniques include among others, computer tomography, three-dimensional (3D) photogrammetry, high resolution ultrasound, and 3D laser scanning. There are advantages and disadvantages for each technique.With the rapid advance of 3D technologies that have become readily available to clinicians, new clinical applications continually emerge to guide and facilitate reconstructive procedures. The authors explored the possibility of fabricating a 3D printed surgical guide to define volume differences for soft tissue reconstruction in patients with facial asymmetry. The model was developed through the authors' virtual surgical simulation and planning system that consists of computer-assisted design (CAD) and 3D printing (3DP).Three-dimensional volumetric scans of patients' faces were analyzed with computer-aided design to quantify areas of facial asymmetry. Surgical guides with containers defining volumetric differences were fabricated using 3D printing to identify and quantify areas of soft tissue deficiency. The 3D printed patient-specific, guides were sterilized and used by the surgeon intraoperatively to accurately mark the areas of soft deficiency. Thus, facial symmetry was achieved by fat grafting the predetermined volume differences defined in the surgical guides. A postop mask was used by the surgeon at the end of the procedure and during follow-up clinic visit to verify and evaluate accurate fat grafting placement as well as to determine areas where to add volume if needed.This paper details the rational for the authors' approach, outlines the technical planning and fabrication process of these patient-specific custom surgical guides with quantified volumetric containers and their intraoperative use by the surgeon. Despite the authors' limited experience we conclude that the authors' technique offer surgeons a precise means for accurate volumetric reconstruction of facial asymmetry.