BACKGROUND: Surgical simulation serves as a key tool in medical training. Three-dimensional (3D) printing technology may be useful in this effort by allowing for rapid prototyping of affordable, custom anatomic models which can be optimized to target specific surgical skills. Carefully designed simulators can accelerate the learning curve of junior residents, especially for procedures that may be difficult to learn in the live operative setting. One procedure that is particularly difficult to master in early training is rhinoplasty; residents often report lack of comfort with performing the osteotomy portion of the procedure. Herein, the purpose of this project was to develop a 3D printed osteotomy training model that is cost-effective and durable, providing educational utility that can be translated to the operating room.
METHODS: Our osteotomy trainer consists of 3 parts: a reusable facial bone base, a replaceable nasal bone cartridge, and a reusable soft tissue envelope. Data obtained from a healthy patient’s head CT scan were used to segment relevant bony structures (orbits, nasal bone, maxilla) to create the reusable facial bone base, and Blender Software (Amsterdam, The Netherlands) was used to design the nasal bone cartridge. Both of these units were printed from ABS Filament on a UPrint SE+ 3D printer (Stratasys, Eden Prairie, MN). The nasal bone cartridge, which is meant to be broken with an osteotome, is firmly fastened to the facial bone base via digitally incorporated pegs and can be easily replaced for repeat use. Finally, to generate the silicone-based “soft tissue” of the face, we designed and 3D printed a mold derived from the same patient CT scan. Once cured, these reusable silicone soft tissue envelopes were draped over the bony structures (facial bone base with fastened nasal cartridge) to complete the setup of our osteotomy trainer. For a beginner model, we used transparent silicone to allow for easy visualization of the underlying bones. For an advanced model, we used skin-colored silicone, which removes the handicap of direct visualization and challenges users to rely on a foundational understanding of anatomy and tactile feedback.
RESULTS: To test durability of the model, 10 osteotomies were performed. Preliminary trials demonstrated the silicone soft tissue construct to be durable enough to withstand multiple osteotomies without breakdown, and osteotomy manipulations yielded noticeable changes in the overlying nasal soft tissue appearance. Additionally, the nasal bone cartridges felt anatomic when broken during the osteotomy simulations, and they were easily replaced for cost-efficient, repeat practice. The total cost of material for the reusable soft tissue envelope and reusable bony base was $25, and the replaceable nasal bone cartridges cost $5.
CONCLUSIONS: This pilot study determined that 3D printing and silicone casting can be used to produce a cost effective and reproducible training tool to practice the osteotomy during rhinoplasty. Future directions include validating this 3D printed training model for educational utility among plastic surgery residents.