Whole-ear finite element analysis of superior semicircular canal dehiscence and its impact on inner-ear responses

Abstract

Objective: To establish a high-fidelity finite element method (FEM) model of the human inner ear and explore the biomechanical effects of superior semicircular canal dehiscence (SCD) on both cochlear and vestibular function.

Methods: A detailed FEM model of the entire human ear was reconstructed from high-resolution computed tomography (CT) data. The model was validated through comparison with established experimental data, including basilar membrane (BM) displacement patterns, cochlear tonotopy, inner ear impedance, and middle-ear transfer function. After validation, the model was adapted to simulate SCD.

Results: The simulated outcomes were consistent with published in-vitro and in-vivo findings, indicating the accuracy of the model. The introduction of SCD resulted in attenuated BM displacement, a marked reduction in cochlear impedance, and an increase in vestibular sensitivity to air-conducted stimuli.

Conclusion: This study developed and validated a whole-ear FEM model demonstrating that SCD produces low-frequency conductive hearing loss and enhances vestibular sound responses. These findings provide explanations for clinical symptoms and VEMP findings, while also revealing the influence of intracranial pressure. Collectively, this model serves as a valuable tool for advancing pathophysiological and diagnostic research.

Keywords: Basilar membrane; Cochlear impedance; Finite element method; Membranous labyrinth; Semicircular canal dehiscence; Vestibular apparatus.