# A Novel 3D-Printed Training Platform for Ossiculoplasty with Objective Performance Evaluation
## 4 Discussion  
In this study, we tested the suitability of 3D-printed incudes for practicing autologous ossiculoplasty. Ossiculoplasty (OPL) continues to be a surgical technique that is often sidelined during training programs of young surgeons. Like previous studies in otology, our research supports the idea that 3D printing technology may provide a cost-effective and easily repeatable training solution, with a high level of fidelity in reproducing the surgical conditions. Specifically, we focused on the potential beneficial effect of performing ossiculoplasty first on magnified 3D-printed incudes, before transitioning to real-sized incudes. To the authors' knowledge, this hypothesis has not been previously investigated, and no group has proposed a standardized scoring system to objectively assess the trainee performance in this surgical technique. Particularly, the existing literature remains sparse regarding studies focusing exclusively on OPL. [PERSON] et al. [34], developed a 3D-printed multimaterial and multicolor temporal bone model with significant anatomical detail and closely resembling human cadaver specimens for drilling and dissection. The model was intended for total temporal bone dissection and it was also possible to insert a cochlear implant. [PERSON] et al. [36], anatomically validated a 3D-printed pediatric middle ear model for endoscopic ear surgery, despite participants were not involved in dissecting the model. [PERSON] et al. [31],  
Figure 7: (**A**) Questions of the qualitative questionnaire posed to all participants. (**B**) Results of the qualitative questionnaires obtained for Group A (**left**) and results obtained from Group B (**right**). focused on the resolution of the imaging to produce accurate 3D-printed ossicle models and proposed a new design of customized middle ears, to have better long-term results in ossiculoplasty. However, the study did not focus on practical ossiculoplasty tasks. [PERSON] et al. [33], demonstrated the efficacy of 3D-printed anatomical models of the ear to study anatomy compared to cadaver, while [PERSON] et al. [35], developed an artificial middle ear model combining 3D printing and silicone rubber molding with a reproducible acoustic behavior. [PERSON] et al. [29], [PERSON] et al. [32], and [PERSON] et al. [30], investigated different 3D printing materials and designs to realize innovative middle ear prostheses. The studies were conducted on cadavers, starting from CBCT and micro-CT imaging, respectively. Both groups demonstrated the feasibility of designing a customized prosthesis from patient imaging, but both agreed about the need for more data to investigate the acoustic properties and real biocompatibility of 3D-printed materials. Regarding the need for specific training for OPL, [PERSON] et al. [28] was the only study that focused on practical OPL, integrating 3D-printed temporal bone models and middle ear prosthesis in otosurgical training. The participants had a rigid 3D-printed temporal bone model: They had to establish anatomical landmarks of the middle ear and then perform OPL. After the completion of OPL task, they had to insert a 3D-printed PORP and at the end of the simulation the participants had to complete a qualitative questionnaire. Despite the focus being more on practice for ossiculoplasty, the feedback was qualitative rather than quantitative. Our findings demonstrate that initial practice on a magnified 3D-printed incus significantly enhanced the trainee's experience in OPL. Group A, which began training on the magnified model before transitioning to the real-sized incus, achieved an impressive 87% of acceptable results. Indeed, the performance of Group A on real-sized incus could have also been influenced by the task repetition. However, when passing from the scaled incus to the real-sized one, the task cannot be considered the same, since it involves substantial operational differences, such as microscope focusing, the grip and handling on the ossicle and the size of the drill.