An Animal Phonatory Model with The Unilateral High Stiffness Curved Surface Asymmetric Vocal Fold

Objective: Patients with glottic cancer usually undergo voice deterioration due to insufficient glottic closure after cordectomy. We aimed to develop a sizeable left-right mismatch asymmetric vibration animal model to reconstruct high stiffness and smooth material vocal fold match normal vocal fold oscillation, which can restore a near-normal voice after cordectomy.

Methods: Twelve larynges removed from adult mongrel dogs were first used for the control group in the excised larynges phonation model of canine. The unilateral vocal fold of animals was reconstructed for RHSCS (reconstructed high stiffness cambered surface) vocal fold by silicone column after cordectomy. The phonation threshold flow(PTF), phonation threshold pressure(PTP), acoustic signals, and ultra-high-speed video images were recorded in the larynges phonation models of the canine. The vocal fold vibration amplitude was measured for two groups separately.

Results: The RHSCS vocal fold asymmetric phonation models produced a voice whose parameters (PTF, F0, jitter, shimmer, HNR) had no significant differences compared to the symmetric bilateral regular vocal fold oscillation. An exception was the significant increase of PTP and PTW in the RHSCS vocal fold model compared to the symmetric phonation model.

Conclusion: Our study reveals that high stiffness, smooth, and curve surface reconstruction of asymmetric vocal folds model can produce a near-normal voice within a range of intensity.