Aging voice and the laryngeal muscle atrophy.

OBJECTIVES/HYPOTHESIS: To study by means of morphometric measurements the severity of vocal muscle atrophy in the elderly. STUDY DESIGN: Cadaver study. SETTING: Universidade Estadual Paulista (UNESP), Botucatu Medical School, Brazil. SUBJECTS AND METHODS: Thirty vocal folds were collected from necropsies distributed into three groups: aged 60 to 75 years (n=10); aged 76 to 90 years (n=10); and a control group aged 30 to 50 years (n=10). Specimens for histology were obtained from the middle portion of the vocal folds. The stained specimens were analyzed using Axion Vision software (coupled to a Zeiss [Oberkochen, Germany] microscope) and used in the morphometric analyses conducted with the ImageJ software. The diameters of 200 muscle fibers from each slide were measured, and the mean values were statistically analyzed. RESULTS: The mean values of the diameters of the vocal muscle fibers of the elderly age groups were smaller than in the control: control (30-50 years: 16.389 µm); elderly (60-75 years: 14.412 µm; 76-90 years: 14.162 µm) (P<0.01). No statistical differences were observed between genders. CONCLUSION: The morphometric analysis showed smaller diameters of vocal muscle fibers in the elderly when compared to controls, demonstrating the atrophy of the muscle. No statistical differences were observed between genders. LEVEL OF EVIDENCE: N/A.

Maximum phonation time and s/z ratio in a large child cohort.

AIM: The purpose of this study was to provide normal values for maximum phonation time (MPT) and the s/z ratio by examining 1660 children aged 4-12 years and without vocal signs or symptoms. METHODS: The technique was based on the sustained emission of the /a/ vowel and fricatives /s/ and /z/. RESULTS: The average of the MPT in children of the different age groups was as follows: 6.09 seconds for the age group 4-6 years (males, 5.97; female, 6.21 seconds), 7.94 seconds for the age group 7-9 years (males, 8.07; females, 7.79 seconds), and 8.98 for the age group 10-12 years (males, 9.05; females, 8.92 seconds). The overall average for males was 7.78 and females 7.64 seconds. The s/z ratio was near 1.0 in most children but above 1.2 in 133 children and below 0.8 in 133 children. CONCLUSION: These values of MPT and s/z ratio can be used as normative in further pediatric studies.