Our case series demonstrates potential benefits and indications for 3D printing in veterinary oral and maxillofacial surgery by improving the diagnosis and treatment of pathology through more accurate preoperative planning. Our 3D printed skull in Case 1 with maxillary osteosarcoma enhanced both the surgeon’s and pet owner’s understanding of the tumor extent leading to the augmentation of treatment plan from curative intent surgery with wide margin to conservative margin with postoperative radiation therapy in order to reduce the potential high risk of morbidity with wide margin. Traditional 2D images of CT or CBCT can be challenging for pet owners to interpret; allowing the owners to see and physically manipulate the 3D model of their pet facilitated comprehension of the surgical complexity, possible complications, and enriched the informed consent process resulting in proceeding with the conservative margin surgery followed by radiation therapy as in Case 1.
Patient-specific 3D printed models can also facilitate complex surgical planning with the ability to simulate the surgical steps in advance including planning of osteotomy lines and pre-contouring of titanium plates for reconstruction. The fabrication of custom-fitting surgical guides for osteotomies further translates the virtual preoperative plan to surgery by improving the precision and accuracy for optimal postoperative result [8]. These benefits have been shown to reduce surgical time and cost [9, 10]. Winer et al. reported saving at least 15 minutes of intraoperative time using 3D printed skulls for pre-contouring reconstruction plates in 19 veterinary patients [4]. The complication risk in canine oral surgery, specifically with mandibulectomy and maxillectomy, is increased by 36% for each additional hour of surgery [11]. Thus, minimizing surgical time with improved preoperative planning and intraoperative guidance from 3D printed models and surgical guides has the potential to improve patient outcomes.
In addition to preoperative planning and intraoperative guidance, 3D printed models may enhance veterinary trainee education. Preece et al. demonstrate that students who used 3D models performed better and had a better learning experience than those using digital models or textbooks suggesting that 3D models enhance understanding of anatomical structures and their relationships [12]. Patient specific 3D printed models further facilitate trainee’s understanding of the complex surgical anatomy, potentially reducing the need for cadaveric specimens as well as morbidity and mortality for patients during their surgical experience on living patients [5]. Incorporation of 3D printing in training of surgeons is well documented including a program at the University of North Carolina at Chapel Hill that fabricates patient specific models to train surgical residents [13].
Most barriers and limitations of 3D printed models include the upfront cost of acquiring a 3D printer, materials, segmentation software, the expertise required for the fabrication process and quality assurance, and the time needed for printing and post-processing. However, 3D printing has become more accessible with desktop vat polymerization technology making it more affordable with a smaller footprint printer minimizing the space requirement while maintaining the high resolution needed for accurate fabrication of the complex delicate maxillofacial anatomy. The multitude of materials including biocompatible materials that can be sterilized for intraoperative patient contact use will likely facilitate further adoption of 3D printing in the clinical and surgical setting. Depending on the size and complexity of the canine skull, it took between 10 to 36 hours to complete the printing process for our case series and approximately 2 additional hours for post-processing. However, the 3D printing and post-processing time required did not negatively impact patient care in the cases highlighted in this series. For all three cases the printing and processing occurred during pre-surgical planning. As such, in general, we would not expect the time commitment required to complete the 3D printing process to affect patient care as the candidates selected for 3D printing are usually complex cases that require preoperative imaging acquisition followed by a stage procedure for thorough diagnosis and preoperative planning. Thus, the 3D printing process takes place concurrently with the preoperative surgical planning prior to the scheduled surgery. With advancement of 3D printing technologies, production time and cost will likely continue to decrease.
In conclusion, 3D printed models can improve preoperative planning and intraoperative guidance while enhancing veterinary training and pet owner communication. As 3D printing technology continues to advance, there will be increased adoption in veterinary medicine as it is already evidenced in human medicine with more hospitals offering medical 3D printing and recently approved Current Procedural Terminology (CPT) codes for reimbursement.