Objectives/hypothesis: To quantitatively characterize arytenoid movement induced by vocal fold injection augmentation in an excised larynx model.
Study design: : Laboratory and computational.
Methods: Vocal folds of human cadaveric larynges were injected with calcium hydroxylapatite. High-resolution computed tomography scans were obtained before and after injection. Densities corresponding to the arytenoid and cricoid cartilages were extracted and processed with custom MATLAB routines to generate selective three-dimensional reconstructions of the larynx. Pre- and postinjection positions of the arytenoid were compared.
Results: Vocal fold injections resulted in predominantly small-magnitude medial rotation and medial translation of the arytenoid. Movements in other directions as would be expected in physiologic adduction were not observed.
Conclusions: Vocal fold injection augmentation induced passive movement of the arytenoid that has not been described previously. This movement does not reproduce the trajectory of physiologic adduction. This finding has implications for the treatment of unilateral vocal fold paralysis without arytenoid repositioning maneuvers.