Effect of vocal fold injury location on vibratory parameters in excised canine larynges.
OBJECTIVE
To investigate the effect of vocal fold injury location on vibratory amplitude and lateral phase difference.


METHODS
Repeated measures with each excised canine larynx serving as own control.


METHODS
Basic science study conducted in university laboratory.


METHODS
Vocal fold vibration of excised canine larynges was recorded with a high-speed camera before and after inducing vocal fold injury at 1 of 5 locations: anterior, middle, posterior, medial, or superior. Medial and superior injuries were created within the middle third of the vocal fold. Five larynges were used for each of the 5 injury locations. Kymography was performed at the midpoint of the vocal folds for each video. Pre- and postinjury vibratory amplitude and lateral phase difference were compared for each location.


RESULTS
The anterior and medial injuries produced consistent decreases in vibratory amplitude. Middle and posterior injuries might slightly decrease amplitude. Superior injuries seemed to have no effect on amplitude. Anterior and medial injuries induced phase asymmetry between the right and left vocal folds. Middle injuries appeared to affect phase difference slightly, whereas posterior and superior injuries had no effect.


CONCLUSIONS
Injury to the anterior or medial portions of the vocal fold may be most likely to cause abnormal vocal fold vibration. Using caution in these locations during phonosurgery may favor superior postoperative vocal outcomes.
Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53706, USA.
Christopher R
CR
Krausert
Di
D
Ying
Seong Hee
SH
Choi
Matthew R
MR
Hoffman
Jack J
JJ
Jiang
D000704:Analysis of Variance; D000818:Animals; D004195:Disease Models, Animal; D004285:Dogs; D015601:Injury Severity Score; D007734:Kymography; D007825:Laryngectomy; D011897:Random Allocation; D012016:Reference Values; D014732:Vibration; D014743:Videotape Recording; D014827:Vocal Cords / Q000293:injuries*