Some aspects of vocal fold bowing

Area of Science:

• Otolaryngology
• Laryngology
• Voice Science

Background:

• Vocal fold bowing is a recognized clinical observation.
• Its etiology is not fully understood, particularly in cases without apparent organic pathology.
• Understanding bowing mechanisms is crucial for diagnosing and managing voice disorders.

Purpose of the Study:

• To investigate the causes and mechanisms of vocal fold bowing.
• To analyze the prevalence of bowing in different patient groups: vocal fold paralysis (VFP), sulcus vocalis, post-laser surgery, and idiopathic dysphonia.
• To explore potential correlations between bowing and specific laryngeal muscle activity or patient demographics.

Main Methods:

• Retrospective review of fiberscopic videorecordings from 226 patients.
• Inclusion criteria: 127 patients with VFP, 33 with sulcus vocalis, 33 post-laser surgery, and 33 with dysphonia and no organic lesion.
• Correlation analysis with electromyography data for thyroarytenoid and cricothyroid muscle activity where available.

Main Results:

• Vocal fold bowing was observed in 69% of paralyzed vocal folds, significantly related to thyroarytenoid muscle activity.
• All vocal folds with sulcus vocalis exhibited bowing.
• Bowing occurred in 35% of post-laser surgery cases, related to the extent of tissue removal.
• Twelve cases (approx. 9%) presented bowing without organic lesions; 8 were male, 9 were over 60, suggesting age-related mucosal changes.

Conclusions:

• Vocal fold bowing is strongly associated with vocal fold paralysis, sulcus vocalis, and laser surgery.
• Thyroarytenoid muscle activity is a significant factor in bowing associated with paralysis.
• Age-related mucosal changes may cause bowing in older patients without identifiable lesions; causes in younger patients remain unclear.