INTRODUCTION: The vocal folds of elderly individuals have a characteristic morphology that justifies the vocal pattern of this age group. One of the most important changes to occur in the larynx of the elderly population is atrophy of the vocal muscle, which is responsible for varying degrees of glottic insufficiency. AIM: To analyze, by means of morphometric measurements, the degree of vocal muscle atrophy among the elderly. METHODS: Sixty-one vocal folds from necropsies were allocated to 3 age groups: 60-75 years (n = 21), 76-90 years (n = 22), and 30-50 years (n = 18, control group). The vocal folds were longitudinally sectioned and embedded in paraffin to obtain 4-µm-thick sections that were stained with PAS (Periodic acid-Schiff). The slides from each patient were photographed with Axion Vision software and the morphometric analyses were performed using Image J software and measurements of the diameter of 200 transversely sectioned muscle fibers (µm). RESULTS: The diameter of the muscle fibers decreased with age (15.702 µm vs. 15.225 µm vs. 15.200 µm for the 30-50 year-old control group, 60-75 year-old age group, and 76-90 year-old age group, respectively). CONCLUSION: Changes in the diameter of the vocal muscle fibers can be identified from age 60 years and progress with age. Presbyphonia thus appears to be associated with alterations in the type of muscle fibers from glycol tic (greater diameter, lighter, and more resistant to fatigue) to oxidative (smaller diameter, more osinophilic, less resistant to fatigue).
