On the use of 3D modeling, reconstruction and printing techniques for the development of a total ossicular replacement prosthesis: a case study of cholesteatoma.

Abstract

The middle ear, which lies between the external auditory canal and the inner ear (cochlea), comprises the tympanic membrane, the ossicular chain (i.e. malleus, incus, and stapes), as well as the associated muscles, ligaments, and the middle ear cavity. Its primary function is to transmit vibratory energy (sound pressure) from the air to the cochlear fluids via the ossicular chain. This part of the ear can be damaged by cholesteatoma, which can affect all three ossicles, necessitating ossiculoplasty to restore sound transmission. Ossiculoplasty is the preferred intervention for restoring the mechanism of sound transmission in patients with ossicular deformities. However, the complexity and extended duration of the surgery can significantly impact the patient's quality of life. To address these challenges, our work employs 3D printing technology for the reconstruction of the patient's ear ossicles. This involves detailed 3D modeling and reconstruction of the ear ossicles to obtain precise measurements and visualize the unique anatomical structure of each patient. The model presented in this study is a prototype designed to validate the form and dimensions of a total ossicular replacement prosthesis. Our radiologists and traumatologists reviewed both the form and dimensions and deemed them realistic, ensuring they aligned with clinical requirements. It is important that medical devices, especially those designed for long-term implantation, must undergo strict regulatory testing, which can take several years. Standards such as International Organization for Standardization 13485, 14971, and 5832 require thorough validation to ensure safety, effectiveness, and quality. While this prototype represents an important step, further testing, and regulatory approval will be necessary before it can be used in clinical settings. By leveraging advanced materials and precise 3D printing techniques, these custom-made prostheses simplify the surgical procedure and enhance patient outcomes by providing tailored solutions that meet specific anatomical and functional needs. This innovative approach represents a significant advancement in treating ossicular deformities, ensuring both efficacy and improved patient satisfaction.