Effects of Superomedial Partial Arytenoidectomy on Incomplete Posterior Glottal Closure Caused by Arytenoid Positional Asymmetry in Excised Human Larynges.

OBJECTIVES: To analyze the effects that arytenoid positional asymmetry has on posterior glottic closure and to determine whether superomedial partial arytenoidectomy (SPA) can provide a benefit in cases of such asymmetry. METHODS: In this experimental study, we evaluated posterior glottic closure in 10 larynges freshly excised from human cadavers, measuring the distance between the vocal processes before and after artificially simulated positional asymmetry of the arytenoid cartilages. We then performed SPA, after which we again measured the distance between the vocal processes. RESULTS: In all of the larynges studied, the posterior glottic closure went from complete to incomplete after simulation of arytenoid positional asymmetry, the median distance observed between the vocal processes being 1.74mm (interquartile range 0.22). The SPA performed after arytenoid asymmetry caused the posterior glottic closure to return from incomplete to complete in all of the larynges studied. CONCLUSION: Our results suggest that arytenoid positional asymmetry impairs posterior glottic closure and that SPA improves posterior glottic closure in such cases of arytenoid asymmetry.

Excised human larynx in N-vinyl-2-pyrrolidone-embalmed cadavers can produce voiced sound by pliable vocal fold vibration.

Tissue-hardening effect and health-hazard issue of formaldehyde (FA) have long been a great disadvantage of this conventional fixative in anatomical research. We recently developed a FA-free embalming method for cadavers which utilizes N-vinyl-2-pyrrolidone (NVP) and enables assessment of motion kinetics by maintaining the softness of embalmed tissue. By assessing the feasibility of NVP-embalmed tissue to mimic vocalization, this study aimed to prove the potential of embalmed cadavers, which have previously been used only for the understanding of anatomical morphology, for the assessment of precise motion physiology in the human body. Ten cadavers embalmed in NVP (n = 6) and FA (n = 4) were incorporated in this study. Excised larynges underwent experimental phonation to mimic vocalization with fast and pliable vibration of vocal folds. High-speed digital imaging was utilized for the assessment of vocal fold vibration. Furthermore, acoustic analysis of the voiced sound, and reproducibility examination were also performed. Regular vocal fold vibrations successfully produced voiced sounds during experimental phonation using NVP-embalmed larynges. The vibratory frequency, vibration amplitude, and stretch rate of the vocal folds were comparable to those of living humans. Six months after the first experiment, the vocal parameters were reproduced, to suggest the long-term preservation potential of our NVP-embalming technique. On the other hand, neither voiced sound nor vocal fold vibration were observed in FA-embalmed larynges. This novel embalming technique could pioneer the next era to utilize embalmed cadavers for the examination of motion physiology in the human body.

Bipedicled Vocal Fold Mucosal Flap: An Experimental Study.

OBJECTIVE: To determine the dimensions of mucosal defects that can be covered by a bipedicled vocal fold mucosal flap. METHODS: We used 20 adults human larynges (10 of each gender) excised from cadavers, divided into 2 groups of 10 larynges (5 of each gender) each. In one group (the normal flap group), we created the largest possible bipedicled vocal fold mucosal flap and then quantified the dimensions of the largest defect that could be covered by displacing the flap medially. In the other group (the augmented flap group), the flap was augmented laterally with mucosa from the laryngeal ventricle and we determined whether the larger flap would effectively cover larger defects. RESULTS: The mean width of mucosal defect capable of being covered was 1.51 mm when the normal bipedicled flap was employed and was 1.67 mm when the augmented flap was applied. However, the difference was not statistically significant. We found that defect size correlated with vocal fold length, width and flap size in the normal flap group, whereas it correlated only with vocal fold length in the augmented flap group. The bipedicled flap is capable of covering larger defects in males. CONCLUSION: Enlargement of a bipedicled vocal fold mucosal flap with laryngeal ventricular mucosa does not necessarily translate to an increase in the size of defect that can be covered. On average, the flap should be 30% larger than the width of the defect. The statistical model for predicting the defect size based on the vocal fold length, vocal fold width, and flap size has excellent predictive quality when a normal flap is employed.

Source and Filter Acoustic Measures of Young, Middle-Aged and Elderly Adults for Application in Vowel Synthesis.

INTRODUCTION: The output sound has important changes throughout life due to anatomical and physiological modifications in the larynx and vocal tract. Understanding the young adult to the elderly speech acoustic characteristics may assist in the synthesis of representative voices of men and women of different age groups. OBJECTIVE: To obtain the fundamental frequency (f0), formant frequencies (F1, F2, F3, F4), and bandwidth (B1, B2, B3, B4) values extracted from the sustained vowel /a/ of young, middle-aged, and elderly adults who are Brazilian Portuguese speakers; to present the application of these parameters in vowel synthesis. STUDY DESIGN: Prospective study. METHODS: The acoustic analysis of tokens of the 162 sustained vowel /a/ produced by vocally healthy adults, men, and women, between 18 and 80 years old, was performed. The adults were divided into three groups: young adults (18 to 44 years old); middle-aged adults (45 to 59 years old) and, elderly adults (60 to 80 years old). The f0, F1, F2, F3, F4, B1, B2, B3, B4 were extracted from the audio signals. Their average values were applied to a source-filter mathematical model to perform vowel synthesis in each age group both men and woman. RESULTS: Young women had higher f0 than middle-aged and elderly women. Elderly women had lower F1 than middle-aged women. Young women had higher F2 than elderly women. For the men's output sound, the source-filter acoustic measures were statistically equivalent among the age groups. Average values of the f0, F1, F2, F3, F4, B1, and B2 were higher in women. The sound waves distance in signals, the position of formant frequencies and the dimension of the bandwidths visible in spectra of the synthesized sounds represent the average values extracted from the volunteers' emissions for the sustained vowel /a/ in Brazilian Portuguese. CONCLUSION: Sustained vowel /a/ produced by women presented different values of f0,F1 and F2 between age groups, which was not observed for men. In addition to the f0 and the formant frequencies, the bandwidths were also different between women and men. The synthetic vowels available represent the acoustic changes found for each sex as a function of age.

Bipedicled Vocal Fold Mucosal Flap Use in Phonomicrosurgery: Case Series.

OBJECTIVES: The objective of this study was to present a novel surgical technique involving the use of a "bipedicled vocal fold mucosal flap" to repair a mucosal defect and to evaluate the outcomes of patients in whom it was used. MATERIAL AND METHODS: This was a retrospective study of 6 clinical cases. All patients underwent surgery between November 2000 and July 2018, and all procedures were performed by the same surgeon. For the auditory-perceptual assessment, the Grade-Roughness-Breathiness-Asthenia-Strain hoarseness scale was used. We based the stroboscopic evaluation on the European Laryngological Society protocol, analyzing the parameters glottal closure, mucosal wave, and phase symmetry. RESULTS: Ages at the time of surgery ranged from 10 to 52 years, and all of the patients were male. Preexisting vocal fold lesions included polyps, cysts, a sulcus, and mucosal bridges. Among the stroboscopic parameters, only the mucosal wave differed significantly between the preoperative and postoperative periods (P = 0.046). There were also significant postoperative improvements in the overall grade of dysphonia (P = 0.025) and in the degree of breathiness (P = 0.025). CONCLUSIONS: The use of a bipedicled vocal fold mucosal flap appears to promote significant improvements in the mucosal wave and in voice quality. In the patients evaluated here, the technique was used without preoperative planning. However, it proved to be a safe and appropriate means of repairing mucosal defects in the vocal folds, with the potential to preserve rheological properties and promote healing with less chance of fibrosis.

Variant of the Technique for Laryngeal Microsurgery in Cases of Difficult Laryngoscopy

Abstract Introduction Low exposure of the larynx can make laryngeal microsurgery difficult or even impossible. The application of rigid and contact endoscopy enabled oblique and retrograde angled visualization, allowing transoperative staging with greater reach of the anatomical areas. However, there is difficulty or even impossibility of performing the surgical act, due to the incompatibility of the angled path with the straight surgical tools. Objective To demonstrate the efficiency of the variant of the technique for laryngeal microsurgery in cases of difficult laryngoscopy and to analyze the new surgical instruments specific to the endoscopic procedure. Methods This is a cross-sectional retrospective study, based on the analysis of 30 medical records of patients treated surgically at a philanthropic hospital in the state of Sergipe, Brazil, between the years of 2014 and 2015. Results The technical variant used 30- and 70-degree endoscopes that provided complete oblique view of the endolarynx. The association of angled instruments (forceps, suction pumps, retractors and scissors) enabled the execution of the surgical procedures. Conclusion The association of rigid endoscopy with angled instruments promoted full visualization of the surgical lesion and operative resolution. (AU)

Variant of the Technique for Laryngeal Microsurgery in Cases of Difficult Laryngoscopy.

Introduction Low exposure of the larynx can make laryngeal microsurgery difficult or even impossible. The application of rigid and contact endoscopy enabled oblique and retrograde angled visualization, allowing transoperative staging with greater reach of the anatomical areas. However, there is difficulty or even impossibility of performing the surgical act, due to the incompatibility of the angled path with the straight surgical tools. Objective To demonstrate the efficiency of the variant of the technique for laryngeal microsurgery in cases of difficult laryngoscopy and to analyze the new surgical instruments specific to the endoscopic procedure. Methods This is a cross-sectional retrospective study, based on the analysis of 30 medical records of patients treated surgically at a philanthropic hospital in the state of Sergipe, Brazil, between the years of 2014 and 2015. Results The technical variant used 30- and 70-degree endoscopes that provided complete oblique view of the endolarynx. The association of angled instruments (forceps, suction pumps, retractors and scissors) enabled the execution of the surgical procedures. Conclusion The association of rigid endoscopy with angled instruments promoted full visualization of the surgical lesion and operative resolution.

Fundamental Frequency in Excised Human Larynges after Anterior Glottic Web Formation of Various Extents.

OBJECTIVE: To determine the effect of vocal fold anterior web formation on fundamental frequency with a cadaveric excised larynx model. STUDY DESIGN: Experimental study with excised human larynges. SETTING: Academic tertiary care hospital. SUBJECTS AND METHODS: Sixteen freshly excised human larynges were evaluated with high-speed videoendoscopy and digital kymography during artificially produced vibration. Each larynx was assessed in 4 conditions: preoperative controls and after 25%, 33%, and 50% decreases in the vibratory portion of the vocal folds. The following parameters were evaluated: fundamental frequency, periodicity, vocal fold vibration amplitude, phase symmetry, and glottic closure. RESULTS: The mean fundamental frequencies were 208.87, 250.20, 292.37, and 342.67 Hz for preoperative controls and 25%, 33%, and 50% reductions in vibratory length of the vocal folds, respectively. Fundamental frequency increased with each increase in anterior glottic web extent, and the difference among the groups was statistically significant in absolute values in hertz and in semitone elevation. The mathematical models for estimating postoperative fundamental frequency had a statistically significant coefficient. The vibration of the vocal folds remained periodic in all larynges before and after the procedures. CONCLUSION: There was a significant and progressive increase in the fundamental frequency with each enlargement of anterior glottic web. Based on the control frequency, mathematical models could estimate the value of the fundamental frequency after the procedure.

Isolated Paresis of Laryngeal Adduction: What Are the Laryngoscopic and Stroboscopic Findings?

OBJECTIVES/HYPOTHESIS: This study aimed to describe the videolaryngostroboscopic (VLS) findings in a cohort of patients with isolated paresis of laryngeal adduction and identify predictive variables that may be related to voice recovery. STUDY DESIGN: Chart review and VLS analysis of dysphonic patients diagnosed with isolated paresis of laryngeal adduction by laryngeal electromyography (LEMG). METHODS: Demographic, clinical, VLS, and LEMG findings were analyzed according to the outcome of dysphonia. RESULTS: There were 17 patients, 12 males (70.6%), mean age of 46.6 years, with median dysphonia duration of 4 months (range, 1-60 months) included in the study. In all patients, gross movement of both vocal folds were normal. Laryngoscopy showed limited adduction of the ipsilateral ventricular fold, contralateral interarytenoid region deviation, and vocal fold atrophy in 100%, 94.1%, and 76.5% of patients, respectively. VLS findings included: impairment of glottic closure (94.1%), phase asymmetry (94.1%), and reduced mucosal wave on the affected side (76.5%). Predictors of good voice outcome were sudden onset (P = .012), duration of dysphonia on presentation shorter than 5 months (P = .005), and absence of polyphasic potentials on LEMG (P = .041). CONCLUSIONS: Findings on VLS as described suggest isolated paresis of laryngeal adduction and should warrant indication of LEMG for definite diagnosis. Voice improvement may be related to clinical and LEMG findings. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:919-925, 2019.

The Influence of Auditory Feedback and Vocal Rehabilitation on Prelingual Hearing-Impaired Individuals Post Cochlear Implant.

OBJECTIVE: To verify changes in the perceptual and acoustic vocal parameters in prelingual hearing-impaired adults with cochlear implants after vocal rehabilitation. HYPOTHESIS: Auditory feedback restoration alone after cochlear implant is not enough for vocal adjustments. A targeted and specific voice therapy intervention is required. STUDY DESIGN: Prospective and pre-post repeated measures design. METHODS: Twenty literate adults with severe to profound prelingual bilateral sensorineural hearing loss participated in the study; individuals were implanted late and were fluent users of oral language. Ages ranged from 17 to 48 years. All individuals presented normal results in laryngoscopy, and hearing thresholds with the cochlear implant were over 40 dB HL. Individuals were randomly distributed into two groups: Group 1 (treatment group) and Group 2 (control group), both with ten patients each, five men and five women, matching mean age and hearing deprivation time before the cochlear implantation. Patients from Group 1 underwent a protocol of vocal therapy including 12 individual sessions with the same clinician. Group 2 only underwent vocal recordings. The vocal recordings occurred before and after the participation in the therapy protocol for Group 1 and after the same period, 3 months later, without any intervention, for Group 2. The recording sessions used the Consensus Auditory-Perceptual Evaluation of Voice protocol sentence reading and emission of sustained vowel /a/. Auditory-perceptual evaluation of voices was performed by three judges, and the acoustical analysis used the Praat program. RESULTS: Statistically significant reductions in the overall vocal degree, vocal instability, and degree of resonance change were observed after vocal rehabilitation in Group 1. Statistically, individuals from Group 1 did not differ in regard to the modification of acoustic parameters. Group 2 did not present significant changes in any of the analyzed parameters. CONCLUSIONS: The cochlear implanted adults submitted to vocal rehabilitation presented changes in the auditory-perceptual parameters, with reduction of the overall voice severity, vocal instability, and degree of resonance after vocal intervention. There were no changes in the acoustic parameters in the implanted prelingual hearing-impaired adult subjects.

Voice deviation, dysphonia risk screening and quality of life in individuals with various laryngeal diagnoses.

OBJECTIVES: To characterize the voice quality of individuals with dysphonia and to investigate possible correlations between the degree of voice deviation (D) and scores on the Dysphonia Risk Screening Protocol-General (DRSP), the Voice-Related Quality of Life (V-RQOL) measure and the Voice Handicap Index, short version (VHI-10). METHODS: The sample included 200 individuals with dysphonia. Following laryngoscopy, the participants completed the DRSP, the V-RQOL measure, and the VHI-10; subsequently, voice samples were recorded for auditory-perceptual and acoustic analyses. The correlation between the score for each questionnaire and the overall degree of vocal deviation was analyzed, as was the correlation among the scores for the three questionnaires. RESULTS: Most of the participants (62%) were female, and the mean age of the sample was 49 years. The most common laryngeal diagnosis was organic dysphonia (79.5%). The mean D was 59.54, and the predominance of roughness had a mean of 54.74. All the participants exhibited at least one abnormal acoustic aspect. The mean questionnaire scores were DRSP, 44.7; V-RQOL, 57.1; and VHI-10, 16. An inverse correlation was found between the V-RQOL score and D; however, a positive correlation was found between both the VHI-10 and DRSP scores and D. CONCLUSION: A predominance of adult women, organic dysphonia, moderate voice deviation, high dysphonia risk, and low to moderate quality of life impact characterized our sample. There were correlations between the scores of each of the three questionnaires and the degree of voice deviation. It should be noted that the DRSP monitored the degree of dysphonia severity, which reinforces its applicability for patients with different laryngeal diagnoses.

Voice deviation, dysphonia risk screening and quality of life in individuals with various laryngeal diagnoses

OBJECTIVES: To characterize the voice quality of individuals with dysphonia and to investigate possible correlations between the degree of voice deviation (D) and scores on the Dysphonia Risk Screening Protocol-General (DRSP), the Voice-Related Quality of Life (V-RQOL) measure and the Voice Handicap Index, short version (VHI-10). METHODS: The sample included 200 individuals with dysphonia. Following laryngoscopy, the participants completed the DRSP, the V-RQOL measure, and the VHI-10; subsequently, voice samples were recorded for auditory-perceptual and acoustic analyses. The correlation between the score for each questionnaire and the overall degree of vocal deviation was analyzed, as was the correlation among the scores for the three questionnaires. RESULTS: Most of the participants (62%) were female, and the mean age of the sample was 49 years. The most common laryngeal diagnosis was organic dysphonia (79.5%). The mean D was 59.54, and the predominance of roughness had a mean of 54.74. All the participants exhibited at least one abnormal acoustic aspect. The mean questionnaire scores were DRSP, 44.7; V-RQOL, 57.1; and VHI-10, 16. An inverse correlation was found between the V-RQOL score and D; however, a positive correlation was found between both the VHI-10 and DRSP scores and D. CONCLUSION: A predominance of adult women, organic dysphonia, moderate voice deviation, high dysphonia risk, and low to moderate quality of life impact characterized our sample. There were correlations between the scores of each of the three questionnaires and the degree of voice deviation. It should be noted that the DRSP monitored the degree of dysphonia severity, which reinforces its applicability for patients with different laryngeal diagnoses.

Impact of Cricothyroid Muscle Contraction on Vocal Fold Vibration: Experimental Study with High-Speed Videoendoscopy.

OBJECTIVES: The aim of this study was to evaluate the effects of cricothyroid muscle contraction on vocal fold vibration, as evaluated with high-speed videoendoscopy, and to identify one or more aspects of vocal fold vibration that could be used as an irrefutable indicator of unilateral cricothyroid muscle paralysis. STUDY DESIGN: This was an experimental study employing excised human larynges. METHODS: Twenty freshly excised human larynges were evaluated during artificially produced vibration. Each larynx was assessed in three situations: bilateral cricothyroid muscle contraction, unilateral cricothyroid muscle contraction, and no contraction of either cricothyroid muscle. The following parameters were evaluated by high-speed videoendoscopy: fundamental frequency, periodicity, amplitude of vocal fold vibration, and phase symmetry between the vocal folds. RESULTS: Although neither unilateral nor bilateral cricothyroid muscle contraction altered the periodicity of vibration or the occurrence of phase asymmetry, there was a significant decrease in fundamental frequency in parallel with decreasing longitudinal tension. We also found an increase in vibration amplitude of right and left vocal folds, which were similar in terms of their behavior for this parameter in the various situations studied. CONCLUSION: Our results suggest that differences in vibration amplitude and phase symmetry between vocal folds are not reliable indicators of unilateral cricothyroid muscle paralysis.

High-speed Videolaryngoscopy: Quantitative Parameters of Glottal Area Waveforms and High-speed Kymography in Healthy Individuals.

OBJECTIVES: We conducted a study to obtain quantitative parameters of the vocal dynamic using high-speed videolaryngoscopy and to characterize the vocal fold vibration pattern of healthy individuals by analyzing glottal area waveforms and high-speed kymography. METHODS: Laryngeal images of 45 healthy individuals were captured using high-speed videolaryngoscopy. The open and speed quotients of the glottal area waveforms and high-speed kymography were obtained and statistically analyzed according to the gender of each individual. RESULTS: Glottal area waveforms revealed average values of 0.85 and 1.16 for open and speed quotients, respectively, for women, and 0.70 and 1.19 for men. Using high-speed kymography, quantitative parameters of open and speed quotients for women were 0.62 and 1.02, respectively, and for men were 0.57 and 1.12. By gender, a significant statistical difference emerged for open quotients obtained from both glottal area waveforms (P = 0.004) and high-speed kymography (P = 0.013). CONCLUSION: Obtained by using computational tools specifically for analyzing laryngeal images from high-speed videolaryngoscopy, quantitative parameters of glottal area waveforms and high-speed kymography in healthy individuals provide reference data and normality for future studies.

Perturbation Measurements on the Degree of Naturalness of Synthesized Vowels.

OBJECTIVE: To determine the impact of jitter and shimmer on the degree of naturalness perception of synthesized vowels produced by acoustical simulation with glottal pulses (GP) and with solid model of the vocal tract (SMVT). STUDY DESIGN: Prospective study. METHODS: Synthesized vowels were produced in three steps: 1. Eighty GP were developed (20 with jitter, 20 with shimmer, 20 with jitter+shimmer, 20 without perturbation); 2. A SMVT was produced based on magnetic resonance imaging (MRI) from a woman during phonation-/ε/ and using rapid prototyping technology; 3. Acoustic simulations were performed to obtain eighty synthesized vowels-/ε /. Two experiments were performed. First Experiment: three judges rated 120 vowels (20 humans+80 synthesized+20% repetition) as "human" or "synthesized". Second Experiment: twenty PowerPoint slide sequences were created. Each slide had 4 synthesized vowels produced with the four perturbation condition. Evaluators were asked to rate the vowels from the most natural to the most artificial. RESULTS: First Experiment: all the human vowels were classified as human; 27 out of eighty synthesized vowels were rated as human, 15 of those were produced with jitter+shimmer, 10 with jitter, 2 without perturbation and none with shimmer. Second Experiment: Vowels produced with jitter+shimmer were considered as the most natural. Vowels with shimmer and without perturbation were considered as the most artificial. CONCLUSIONS: The association of jitter and shimmer increased the degree of naturalness of synthesized vowels. Acoustic simulations performed with GP and using SMVT demonstrated a possible method to test the effect of the perturbation measurements on synthesized voices.

Vocal Tract Adjustments of Dysphonic and Non-Dysphonic Women Pre- and Post-Flexible Resonance Tube in Water Exercise: A Quantitative MRI Study.

OBJECTIVE: To compare vocal tract (VT) adjustments of dysphonic and non-dysphonic women before and after flexible resonance tube in water exercise (FRTWE) at rest and during phonation using magnetic resonance imaging. STUDY DESIGN: Prospective study. METHODS: Twenty women, aged 20-40 years, 10 dysphonic with vocal nodules (VNG) and 10 controls (CG), underwent four sets of sagittal VT MRI: two pre-FRTWE, at rest and during phonation, and two post-FRTWE, during phonation and at rest. The subjects performed 3 minutes of exercise. Nine parameters at rest and 21 during phonation were performed. RESULTS: Pre-FRTWE, eight significant differences were found, three at rest and five during phonation: at rest - laryngeal vestibule area, distance from epiglottis to pharyngeal posterior wall (PPW) and interarytenoid complex length were smaller in the VNG; during phonation - laryngeal vestibule area, angle between PPW and vocal fold (VF), epiglottis to PPW, and anterior commissure of the larynx to laryngeal posterior wall were smaller in the VNG; tongue area was larger in the VNG. Post-FRTWE, only three significant differences were found, two during phonation and one at rest: during phonation - angle between PPW and VF and the membranous portion of the VF length were smaller in the VNG; at rest - distance from epiglottis to PPW was smaller in the VNG. CONCLUSIONS: Results suggest that the habitual VT adjustments of dysphonic and non-dysphonic women are different at rest and during phonation. The FRTWE promoted positive VT changes in the VNG, reducing the intergroup differences.

Surgical approach to the thyroarytenoid branch of the inferior laryngeal nerve through the thyroid cartilage.

PURPOSE: To describe the anatomical course of the intralaryngeal portion of the inferior laryngeal nerve (ILN) and to standardize the surgical access to its thyroarytenoid branch (TAb) through the thyroid cartilage. METHODS: Under surgical microscopy, 33 adult human excised larynges were dissected, to expose the intralaryngeal portion of ILN. The point of entry of TAb, ILN's terminal branch, in the thyroarytenoid (TA) muscle was determined and correlated with thyroid cartilage dimensions. RESULTS: After entering the larynx, the ILN consistently traveled between the thyroid cartilage and the lateral cricoarytenoid muscle in an anterior and slightly cranial course. The distance from the point of entry of the TAb in the TA muscle to the midline (TAb-H) and to the inferior border (TAb-V) of the thyroid cartilage differed according to gender. In females, mean distances of TAb-H and TAb-V were 20.5mm and 5.2mm and in males, 22.3mm and 5.9mm, respectively. CONCLUSION: The intralaryngeal course of the inferior laryngeal nerve presents low variability and measures from landmarks in the thyroid cartilage help to estimate the point of entry of thyroarytenoid branch in thyroarytenoid muscle.

Surgical approach to the thyroarytenoid branch of the inferior laryngeal nerve through the thyroid cartilage

ABSTRACT PURPOSE: To describe the anatomical course of the intralaryngeal portion of the inferior laryngeal nerve (ILN) and to standardize the surgical access to its thyroarytenoid branch (TAb) through the thyroid cartilage. METHODS: Under surgical microscopy, 33 adult human excised larynges were dissected, to expose the intralaryngeal portion of ILN. The point of entry of TAb, ILN's terminal branch, in the thyroarytenoid (TA) muscle was determined and correlated with thyroid cartilage dimensions. RESULTS: After entering the larynx, the ILN consistently traveled between the thyroid cartilage and the lateral cricoarytenoid muscle in an anterior and slightly cranial course. The distance from the point of entry of the TAb in the TA muscle to the midline (TAb-H) and to the inferior border (TAb-V) of the thyroid cartilage differed according to gender. In females, mean distances of TAb-H and TAb-V were 20.5mm and 5.2mm and in males, 22.3mm and 5.9mm, respectively. CONCLUSION: The intralaryngeal course of the inferior laryngeal nerve presents low variability and measures from landmarks in the thyroid cartilage help to estimate the point of entry of thyroarytenoid branch in thyroarytenoid muscle.

Correlation of the Dysphonia Severity Index (DSI), Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V), and Gender in Brazilians With and Without Voice Disorders.

OBJECTIVES: This study aims to analyze the Dysphonia Severity Index (DSI) in Brazilians with or without voice disorders and investigate DSI's correlation with gender and auditory-perceptual evaluation data obtained via the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) protocol. STUDY DESIGN: A total of 66 Brazilian adults from both genders participated in the study, including 24 patients with dysphonia confirmed on laryngeal examination (dysphonic group [DG]) and 42 volunteers without voice or hearing complaints and without auditory-perceptual voice disorders (nondysphonic group [NDG]). METHODS: The vocal tasks included in CAPE-V and DSI were performed and recorded. Data were analyzed by means of the independent t test, the Mann-Whitney U test, and Pearson correlation at the 5% significance level. RESULTS: Differences were found in the mean DSI values between the DG and the NDG. Differences were also found in all DSI items between the groups, except for the highest frequency parameter. In the DG, a moderate negative correlation was detected between overall dysphonia severity (CAPE-V) and DSI value, and between breathiness and DSI value, and a weak negative correlation was detected between DSI value and roughness. In the NDG, the maximum phonation time was higher among males. In both groups, the highest frequency parameter was higher among females. CONCLUSIONS: The DSI discriminated among Brazilians with or without voice disorders. A correlation was found between some aspects of the DSI and the CAPE-V but not between DSI and gender.