Improving Oral Surgery: A Workflow Proposal to Create Custom 3D Templates for Surgical Procedures

摘要

Background: Computer-guided technologies are adopted in various fields of surgery to limit invasiveness and obtain patient benefits in terms of surgery duration and post-operative course. Surgical templates realized through CAD/CAM technologies are widely diffused in implant dentistry. The aim of this work is to propose, beyond implantology, the feasibility of application of 3D printed surgical templates in oral surgery procedures requiring osteotomies (like maxillary cyst enucleation and tooth disimpaction) in order to obtain accurate surgeries, avoid anatomical damage of surrounding structures and decrease patient’s morbidity, using a simple, low-cost protocol of fabrication. Objective: To provide a reliable CAD-CAM workflow for the realization of surgical templates in oral surgery. Methods: Three clinical scenarios are described: A maxillary canine disimpaction, a mandibular cyst removal, and an orthodontic miniscrew placement. Each one was managed using custom surgical templates realized using the proposed workflow. A Stereolithography (STL) file of maxillary structures was obtained by the use of a 3D medical image processing software (Materialise Mimics 20.0) a segmentation toolbox acquiring RX volumes by Cone-Beam Computed Tomography (CBCT). Digital models of the teeth, acquired as STL files directly, are imported in the same 3D medical image processing freeware (Materialise Mimics 20.0) to merge STL files of maxillary structures and teeth. Data are transported into Blue Sky Plan 4.0 (Blue Sky Bio, LLC), a software for 3D implant guides fabrication, together with the DICOM images package of maxillary volumes to carry out the pre-surgical treatment planning. Anatomical structures at risk are identified; a contour of ideal incision shape and bone osteotomy extent is drawn. Finally, the resulting three-dimensional guide is digitally generated and the surgical guide printed. The resulting 3D template shows the following major features: teeth support, flap management and bone osteotomy design. Results: The proposed work-flow aided the surgeon in both pre-operative and intra-operative work phases through accurate virtual planning and the fabrication of precise surgical guides to be used in oral surgery practice. In each clinical scenario, the use of custom 3D templates allowed better control of the osteotomy planes and flap management. No adverse events occurred during both surgical and healing phases. Conclusion: The proposed digital workflow represents a reliable and straightforward way to produce a surgical guide for oral surgery procedures. These templates represent a versatile tool in maxillary cyst enucleations, tooth disimpaction, and other surgical procedures, increasing accuracy, minimizing surgical complications, and decreasing patient’s morbidity.