Evaluation of a cement incus replacement prosthesis in a temporal bone model

Area of Science:

• Otolaryngology
• Biomaterials Engineering
• Bioacoustics

Background:

• Incus reconstruction requires precise prosthesis length for optimal middle ear function.
• Commercially available incus replacement prostheses (IRPs) may present challenges in achieving ideal clinical fit and tension.
• Dental cement offers a customizable material for creating in-situ hardened incus replacement prostheses (CIRPs).

Purpose of the Study:

• To evaluate the acoustic performance of novel cement incus replacement prostheses (CIRPs) in a human temporal bone model.
• To compare the efficacy of conventional rod-type CIRPs and Y-shaped CIRPs (Y-CIRPs) against standard IRPs.
• To determine if custom-molded CIRPs offer acoustic advantages for incus reconstruction.

Main Methods:

• Experiments were conducted using 12 fresh human temporal bones.
• Incus removal was followed by the implantation of custom-molded dental cement prostheses (CIRPs).
• Acoustic performance was assessed using laser Doppler vibrometry, comparing rod-type CIRPs and two configurations of Y-CIRPs (wide and narrow).

Main Results:

• All tested CIRPs demonstrated superior acoustic performance compared to previously studied conventional IRPs in the same model.
• CIRPs exhibited comparable acoustic function below 2.0 kHz.
• The narrow Y-CIRP design showed the best acoustic performance at frequencies above 3.0 kHz.

Conclusions:

• Custom-molded cement incus replacement prostheses (CIRPs) provide a viable and potentially advantageous alternative for ossicular chain reconstruction.
• The narrow Y-CIRP design may offer specific acoustic benefits for higher frequencies in incus replacement.
• Further investigation into CIRPs, particularly the Y-CIRP design, is warranted for improving post-operative hearing outcomes.