Asymmetric Vibration Animal Phonation Model with A Reconstructive Curved and Medialized Titanium Implant Vocal Fold to Repair Defective Vocal Fold.

OBJECTIVE

Asymmetric vocal fold vibration caused by unilateral biomechanical alteration is common in laryngeal disorders and presents a challenge for functional reconstruction. This study aimed to investigate phonatory and vibratory outcomes in asymmetric glottic configurations reconstructed with materials of different stiffness.

METHODS

Two asymmetric curved-surface (CS) vocal fold models were developed. A silicone-based single-layer model (Si-CS) and a titanium-based bi-layer model (Ti-CS) were constructed and compared with symmetric controls. Twenty-four excised canine larynges were used to establish the Si-CS model. In addition, 20 beagle larynges were harvested following unilateral vocal fold resection and healing after type I thyroplasty with titanium implantation. Phonation threshold pressure (PTP), phonation threshold flow (PTF), phonation threshold power (PTW), acoustic parameters, and high-speed imaging were analyzed.

RESULTS

In the Si-CS model, PTP and PTW were significantly increased compared with controls (P < 0.05), whereas acoustic parameters and vibratory amplitude remained comparable. In the Ti-CS model, both PTP and PTW were significantly elevated (P < 0.05). Fundamental frequency, jitter, and shimmer showed no significant differences, while harmonic-to-noise ratio (HNR) decreased significantly (P < 0.05). High-speed imaging demonstrated reduced vibratory amplitude in the anterior and midfold regions, with relatively preserved posterior vibration.

CONCLUSION

Curved-surface reconstruction with increased stiffness can preserve near-normal phonatory characteristics despite elevated aerodynamic thresholds. Titanium-based asymmetric reconstruction following vocal fold resection maintains vibratory periodicity but alters regional vibratory dynamics and acoustic harmonic structure.