Presented at the Triological Society Annual Meeting, San Diego, California, U.S.A., April 20–21, 2012.
Article first published online: 1 AUG 2012
Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.
Volume 122, Issue 9, pages 2005–2014, September 2012
How to Cite
Mau, T., Muhlestein, J., Callahan, S. and Chan, R. W. (2012), Modulating phonation through alteration of vocal fold medial surface contour. The Laryngoscope, 122: 2005–2014. doi: 10.1002/lary.23451
The authors have no other funding, financial relationships, or conflicts of interest to disclose.
- Issue published online: 23 AUG 2012
- Article first published online: 1 AUG 2012
- Manuscript Accepted: 30 APR 2012
- Manuscript Received: 22 FEB 2012
- Department of Otolaryngology–Head and Neck Surgery, University of Texas Southwestern Medical Center
- University of Texas Southwestern Summer Medical Student Research Program
- National Institute on Deafness and Other Communication Disorders (NIDCD). Grant Numbers: R01 DC006101S1, R01 DC006101, R01 DC005788
- National Institutes of Health
- Vocal fold contour;
- phonation threshold pressure;
- phonation threshold flow;
- vocal fold injection;
- excised larynx
1) To test whether alteration of the vocal fold medial surface contour can improve phonation and 2) to demonstrate that implant material properties affect vibration even when implantation is deep to the vocal fold lamina propria.
Induced phonation of excised human larynges.
Thirteen larynges were harvested within 24 hours postmortem. Phonation threshold pressure (PTP) and flow (PTF) were measured before and after vocal fold injections using either calcium hydroxylapatite (CaHA) or hyaluronic acid (HA). Small-volume injections (median, 0.0625 mL) were targeted to the inferomedial aspect of the thyroarytenoid muscle. Implant locations were assessed histologically.
The effect of implantation on PTP was material dependent. CaHA tended to increase PTP, whereas HA tended to decrease PTP (Wilcoxon test, P = .00013 for onset). In contrast, the effect of implantation on PTF was similar, with both materials tending to decrease PTF (P = .16 for onset). Histology confirmed implant presence in the inferior half of the vocal fold vertical thickness.
Taken together, these data suggested the implants may have altered the vocal fold medial surface contour, potentially resulting in a less convergent or more rectangular glottal geometry as a means to improve phonation. An implant with a closer viscoelastic match to vocal fold cover is desirable for this purpose, as material properties can affect vibration even when the implant is not placed within the lamina propria. This result is consistent with theoretical predictions and implies greater need for surgical precision in implant placement and care in material selection. Laryngoscope, 2012