Viscoelastic Properties of Rabbit Vocal Folds after Augmentation

2003 ◽  
Vol 128 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Stellan Hertegård ◽  
Åke Dahlqvist ◽  
Claude Laurent ◽  
Assunta Borzacchiello ◽  
Luigi Ambrosio
Keyword(s):  
Dynamic Viscosity ◽  
Viscoelastic Properties ◽  
Small Amplitude ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Short Term ◽  
Glottal Insufficiency ◽  
Thyroarytenoid Muscle ◽  
Small Amplitude Oscillation

BACKGROUND: Vocal fold function is closely related to tissue viscoelasticity. Augmentation substances may alter the viscoelastic properties of vocal fold tissues and hence their vibratory capacity. OBJECTIVES: We sought to investigate the viscoelastic properties of rabbit vocal folds in vitro after injections of various augmentation substances. STUDY DESIGN AND SETTING: Polytetrafluoroethylene (Teflon), cross-linked collagen (Zyplast), and cross-linked hyaluronan, hylan b gel (Hylaform) were injected into the lamina propria and the thyroarytenoid muscle of rabbit vocal folds. Dynamic viscosity of the injected vocal fold as a function of frequency was measured with a Bohlin parallelplate rheometer during small-amplitude oscillation. RESULTS: All injected vocal folds showed a decreasing dynamic viscosity with increasing frequency. Vocal fold samples injected with hylan b gel showed the lowest dynamic viscosity, quite close to noninjected control samples. Vocal folds injected with polytetrafluoroethylene showed the highest dynamic viscosity followed by the collagen samples. CONCLUSIONS: The data indicated that hylan b gel in short-term renders the most natural viscoelastic properties to the vocal fold among the substances tested. This is of importance to restore/preserve the vibratory capacity of the vocal folds when glottal insufficiency is treated with injections.

scholarly journals Concurrent YAP/TAZ and SMAD signaling mediate vocal fold fibrosis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ryosuke Nakamura ◽  
Nao Hiwatashi ◽  
Renjie Bing ◽  
Carina P. Doyle ◽  
Ryan C. Branski
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Nuclear Accumulation ◽  
Smad Pathway ◽  
Surgical Interventions ◽  
Smad Signaling ◽  
Iatrogenic Damage ◽  
Tgf Β1

AbstractVocal fold (VF) fibrosis is a major cause of intractable voice-related disability and reduced quality of life. Excision of fibrotic regions is suboptimal and associated with scar recurrence and/or further iatrogenic damage. Non-surgical interventions are limited, putatively related to limited insight regarding biochemical events underlying fibrosis, and downstream, the lack of therapeutic targets. YAP/TAZ integrates diverse cell signaling events and interacts with signaling pathways related to fibrosis, including the TGF-β/SMAD pathway. We investigated the expression of YAP/TAZ following vocal fold injury in vivo as well as the effects of TGF-β1 on YAP/TAZ activity in human vocal fold fibroblasts, fibroblast-myofibroblast transition, and TGF-β/SMAD signaling. Iatrogenic injury increased nuclear localization of YAP and TAZ in fibrotic rat vocal folds. In vitro, TGF-β1 activated YAP and TAZ in human VF fibroblasts, and inhibition of YAP/TAZ reversed TGF-β1-stimulated fibroplastic gene upregulation. Additionally, TGF-β1 induced localization of YAP and TAZ in close proximity to SMAD2/3, and nuclear accumulation of SMAD2/3 was inhibited by a YAP/TAZ inhibitor. Collectively, YAP and TAZ were synergistically activated with the TGF-β/SMAD pathway, and likely essential for the fibroplastic phenotypic shift in VF fibroblasts. Based on these data, YAP/TAZ may evolve as an attractive therapeutic target for VF fibrosis.

Noncontact Determination of the Mechanical Properties of the Human Vocal Folds

2008 ◽  
Author(s):  
Shinji Deguchi ◽  
Kazutaka Kawashima
Keyword(s):  
Mechanical Properties ◽  
Vocal Fold ◽  
Measurement Techniques ◽  
Voice Quality ◽  
Vocal Folds ◽  
In Vivo Measurement ◽  
In Vitro Measurements ◽  
Excited Oscillation

Mechanical properties of the vocal folds (such as stiffness or viscoelastic properties) play an essential role in phonation. They affect not only voice quality but also onset threshold of vocal fold self-excited oscillation, a sound source of voice [1]. Many experimental data on the mechanical properties have been reported so far, in which in vitro [2] or in vivo measurement techniques [3] were employed. In vitro measurements give us detailed information on the mechanical properties, yet it would be required to consider possible loss of freshness of the specimen. Meanwhile, current in vivo measurement methods utilize a thin probe to deform the vocal fold tissue located at the back of the throat and hence need technical skills for the surveyor to successfully obtain its loading-deformation relationship.

Contribution of Glottic Insufficiency to Perceived Breathiness in Classically Trained Singers

2016 ◽  
Vol 31 (3) ◽  
pp. 179-184 ◽  
Author(s):  
Ellen Graham ◽  
Vrushali Angadi ◽  
Joanna Sloggy ◽  
Joseph Stemple
Keyword(s):  
Vocal Fold ◽  
Vocal Folds ◽  
Airflow Rate ◽  
Singing Voice ◽  
Glottic Insufficiency ◽  
Maximum Phonation Time ◽  
Breath Management ◽  
Subglottal Pressure ◽  
Glottal Insufficiency ◽  
Voice Students

Breathiness in the singing voice is problematic for classical singers. Voice students and singing teachers typically attribute breathiness to breath management issues and breathing technique. The present study sought to determine whether glottic insufficiency may also contribute to breathiness in a singer’s voice. Studies have revealed a relationship between insufficient vocal fold closure and inefficiency in the speaking voice. However, the effect of insufficient vocal fold closure on vocal efficiency in singers has yet to be determined. Two groups of voice students identified with and without breathiness issues underwent aerodynamic and acoustic voice assessment as well as laryngeal stroboscopy of the vocal folds to quantify the prevalence of insufficient vocal fold closure, also known as glottic insufficiency. These assessments revealed four groups: 1) those with glottic insufficiency and no perceived voice breathiness; 2) those with glottic sufficiency and perceived voice breathiness; 3) those with glottic insufficiency and perceived breathiness; and 4) those with glottic sufficiency and no perceived breathiness. Results suggest that previously undiscovered glottal insufficiency is common in young singers, particularly women, though the correlation with identified breathiness was not statistically significant. Acoustic and aerodynamic measures including noise-to-harmonics ratio, maximum phonation time, airflow rate, subglottal pressure, and laryngeal airway resistance were most sensitive to glottic insufficiency.

S192 – 3D Diagnosis of Vocalizing Larynx Using Cone Beam CT

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P140-P140
Author(s):  
Koji Inagaki ◽  
Koichiro Saito ◽  
Hideki Naganishi ◽  
Takaoka Takuj ◽  
Momoshima Suketaka ◽  
...  
Keyword(s):  
Vocal Fold ◽  
3D Visualization ◽  
Cone Beam Ct ◽  
Vocal Folds ◽  
Cone Beam ◽  
3 Dimensional ◽  
Scanning Time ◽  
Informative Role ◽  
Glottal Insufficiency ◽  
The Impact

Objectives Cone beam computed tomography (CBCT) was developed for the office-based quick and precise 3D visualization of maxillofacial region. CBCT requires scanning time of less than 10 seconds and provides isotropic 3D image with high resolution. In this study, we examined the potential role of CBCT as a tool for 3-dimensional evaluation of the glottal insufficiency. Methods CBCT was performed in 2 normal controls and in 14 patients with unilateral vocal fold paralysis (13 cases) or paresis (1 case). Laryngeal CBCT images were taken in the resting state and during phonation. Furthermore, preoperative and postoperative images were evaluated to assess the impact of phonosurgeries in 5 cases. Results CBCT of the vocalizing vocal fold was successfully performed in all the cases, producing clear coronal images. During phonation, no remarkable differences in levels between the paralyzed and normal vocal folds were observed in 10 cases, proving the 2-dimensional glottal gap (2D cases). On the other hand, the levels of paralyzed vocal folds stayed higher during phonation compared to the normal side in 4 cases, proving the 3-dimensional glottal gap (3D cases). 4 of the 2D cases had injection laryngoplasty and 1 of the 3D cases had arytenoid adduction procedure to correct their glottal gaps. Postoperative CBCT images verified the successful correction of these gaps. Conclusions Our study proved the feasibility of CBCT for 3D evaluation of vocalizing larynx. This quick and easy system may have an informative role to suggest the proper phonosurgical procedure for glottic insufficiency.

Intraoperative Laryngeal Electromyographic Assessment of Patients with Immobile Vocal Fold

1992 ◽  
Vol 101 (10) ◽  
pp. 799-806 ◽  
Author(s):  
Peak Woo ◽  
Hernando Arandia
Keyword(s):  
Vocal Fold ◽  
Muscle Relaxation ◽  
Motor Units ◽  
Vocal Folds ◽  
Electrode Position ◽  
Recurrent Nerve ◽  
Laryngeal Paralysis ◽  
Vocal Fold Immobility ◽  
Hook Wire ◽  
Thyroarytenoid Muscle

The differential diagnosis of laryngeal ankylosis versus paralysis is occasionally difficult in patients with immobile vocal folds. Eight patients with acute and chronic evidence of vocal fold immobility were investigated by intraoperative electromyography (IEMG) during planned microlaryngoscopy. Bipolar hook wire electrodes were inserted into the thyroarytenoid muscle, of which the electrical activity was monitored during neuromotor blockade and emergence from anesthesia. The normal side and the side with ankylosis or stenosis showed normal IEMG activity. There was progressive recruitment of larger motor units during recovery from muscle relaxation. Patients with laryngeal paralysis failed to show such recruitment patterns. Thus, IEMG can be used as a diagnostic tool during operative laryngoscopy to differentiate neuromotor injury from anatomic causes of vocal fold immobility. The advantages of IEMG are its ease of application and certainty of electrode position. It can also be used to monitor recurrent nerve integrity and detect early laryngospasm. Further IEMG clinical study is warranted.

scholarly journals In vitro mechanical vibration down-regulates pro-inflammatory and pro-fibrotic signaling in human vocal fold fibroblasts

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0241901
Author(s):  
David Hortobagyi ◽  
Tanja Grossmann ◽  
Magdalena Tschernitz ◽  
Magdalena Grill ◽  
Andrijana Kirsch ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Transforming Growth Factor ◽  
Vibrational Excitation ◽  
Smooth Muscle Actin ◽  
Mechanical Vibration ◽  
Vocal Folds ◽  
Alpha Smooth Muscle Actin ◽  
Protein Levels ◽  
Inflammatory Conditions

Introduction Voice rest following phonotrauma or phonosurgery has a considerable clinical impact, but clinical recommendations are inconsistent due to inconclusive data. As biopsies of the vocal folds (VF) for molecular biology studies in humans are unethical, we established a new in vitro model to explore the effects of vibration on human vocal fold fibroblasts (hVFF) in an inflammatory and normal state, which is based on previously published models. Methods By using a phonomimetic bioreactor we were able to apply predefined vibrational stress patterns on hVFF cultured under inflammatory or normal conditions. Inflammatory and pro-fibrotic stimuli were induced by interleukin (IL)1β and transforming growth factor (TGF)β1, respectively. Mechanical stimulation was applied four hours daily, over a period of 72 hours. Outcome measurements comprised assessment of extracellular matrix (ECM)-related components, angiogenic factors, and inflammatory and fibrogenic markers on gene expression and protein levels. Results Under inflammatory conditions, the inflammatory cytokine IL11, as well as the myofibroblast marker alpha smooth muscle actin (α-SMA) were significantly reduced when additional vibration was applied. The desirable anti-fibrotic ECM component hyaluronic acid was increased following cytokine treatment, but was not diminished following vibration. Conclusion Our experiments revealed the effect of vibrational stress on hVFF in an inflammatory state. Elevated levels of certain pro-inflammatory/pro-fibrotic factors could be mitigated by additional vibrational excitation in an in vitro setting. These findings corroborate clinical studies which recommend early voice activation following an acute event.

Human Vocalis Contains Distinct Superior and Inferior Subcompartments: Possible Candidates for the Two Masses of Vocal Fold Vibration

1998 ◽  
Vol 107 (10) ◽  
pp. 826-833 ◽  
Author(s):  
Ira Sanders ◽  
Yingshi Han ◽  
Surinder Rai ◽  
Hugh F. Biller
Keyword(s):  
Vocal Fold ◽  
Muscle Fibers ◽  
Vocal Folds ◽  
Medial Surface ◽  
Vocal Fold Vibration ◽  
Muscle Fascicle ◽  
Superior Surface ◽  
Hematoxylin And Eosin ◽  
Thyroarytenoid Muscle ◽  
Large Muscle

It is not understood how different parts of the thyroarytenoid muscle contribute to vocal fold vibration. This study investigated the medial part of the thyroarytenoid muscle, the vocalis compartment, for anatomic differences that might suggest functionally distinct areas. Twenty human vocal folds were frontally sectioned and stained with hematoxylin and eosin. A single section from the middle of each vocal fold was magnified, and the muscle fascicles of the most superficial 25% of the vocalis compartment were then examined. In all 20 specimens the vocalis compartment could be separated into 2 plainly distinct subcompartments: the inferior vocalis compartment was composed of a single large muscle fascicle that contained densely packed muscle fibers of similar size; the superior vocalis compartment was composed of multiple small fascicles in which the muscle fibers were loosely arranged and varied greatly in size. On average, the inferior vocalis subcompartment composed 60% of the medial surface of the thyroarytenoid muscle. The superior subcompartment composed the remaining 40% of the medial surface, but also continued past the vocal ligament to make up the superior surface of the thyroarytenoid muscle. It is concluded that 2 distinct entities make up the vocalis compartment of the thyroarytenoid muscle. Their anatomy is so markedly different it suggests that they may function independently. One possibility is that they reflect the 2 masses observed in the superior and inferior aspects of the vocal fold during vibration.

Biomechanical Effects of Hydration in Vocal Fold Tissues

2002 ◽  
Vol 126 (5) ◽  
pp. 528-537 ◽  
Author(s):  
Roger W. Chan ◽  
Niro Tayama
Keyword(s):  
Shear Modulus ◽  
Viscoelastic Properties ◽  
Vocal Fold ◽  
Damping Ratio ◽  
Empirical Support ◽  
Tissue Stiffness ◽  
Voice Production ◽  
Vocal Fold Vibration ◽  
Elastic Shear

OBJECTIVE: It has often been hypothesized, with little empirical support, that vocal fold hydration affects voice production by mediating changes in vocal fold tissue rheology. To test this hypothesis, we attempted in this study to quantify the effects of hydration on the viscoelastic shear properties of vocal fold tissues in vitro. STUDY DESIGN: Osmotic changes in hydration (dehydration and rehydration) of 5 excised canine larynges were induced by sequential incubation of the tissues in isotonic, hypertonic, and hypotonic solutions. Elastic shear modulus ( G'), dynamic viscosity η' and the damping ratio ζ of the vocal fold mucosa (lamina propria) were measured as a function of frequency (0.01 to 15 Hz) with a torsional rheometer. RESULTS: Vocal fold tissue stiffness (G') and viscosity increased significantly (by 4 to 7 times) with the osmotically induced dehydration, whereas they decreased by 22% to 38% on the induced rehydration. Damping ratio (ζ) also increased with dehydration and decreased with rehydration, but the detected differences were not statistically significant at all frequencies. CONCLUSION: These findings support the longstanding hypothesis that hydration affects vocal fold vibration by altering tissue rheologic (or viscoelastic) properties. SIGNIFICANCE: Our results demonstrated the biomechanical importance of hydration in vocal fold tissues and suggested that hydration approaches may potentially improve the biomechanics of phonation in vocal fold lesions involving disordered fluid balance.

Influence of Vocal Fold Scarring on Phonation: Predictions from a Finite Element Model

2005 ◽  
Vol 114 (11) ◽  
pp. 847-852 ◽  
Author(s):  
David A. Berry ◽  
Haven Reininger ◽  
Fariborz Alipour ◽  
Diane M. Bless ◽  
Charles N. Ford
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Fundamental Frequency ◽  
Viscoelastic Properties ◽  
Vocal Fold ◽  
Human Subjects ◽  
Vocal Folds ◽  
Element Model ◽  
Acoustic Intensity ◽  
Vocal Fold Vibration

Objectives: A systematic study of the influence of vocal fold scarring on phonation was conducted. In particular, phonatory variables such as fundamental frequency, oral acoustic intensity, and phonation threshold pressure (PTP) were investigated as a function of the size and position of the laryngeal scar. Methods: By means of a finite element model of vocal fold vibration, the viscoelastic properties of both normal and scarred vocal fold mucosae were simulated on the basis of recent rheological data obtained from rabbit and canine models. Results: The study showed that an increase in the viscoelasticity of the scarred mucosa resulted in an increase in fundamental frequency, an increase in PTP, and a decrease in oral acoustic intensity. With regard to positioning of the scar, the PTP increased most significantly when the scar was within ±2 mm of the superior-medial junction of the vocal folds. Conclusions: The systematic data obtained in this investigation agree with the general clinical experience. In the future, these findings may be further validated on human subjects as newly emerging technologies such as linear skin rheometry and optical coherence tomography allow the histologic and viscoelastic properties of the normal and scarred vocal fold mucosae to be measured in the clinic.

Regeneration of Aged Vocal Folds with Basic Fibroblast Growth Factor in a Rat Model: A Preliminary Report

2005 ◽  
Vol 114 (4) ◽  
pp. 304-308 ◽  
Author(s):  
Shigeru Hirano ◽  
Tomoko Tateya ◽  
Hiromi Nagai ◽  
Charles N. Ford ◽  
Ichiro Tateya ◽  
...  
Keyword(s):  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Lamina Propria ◽  
Basic Fibroblast Growth Factor ◽  
Vocal Fold ◽  
Vocal Folds ◽  
Fibroblast Growth ◽  
Collagen Production

Aged vocal folds have been reported to have dense collagen deposition and decreased hyaluronic acid (HA) in the lamina propria. These characteristics are thought to contribute to vocal problems that occur with age (presbyphonia). To restore better viscoelasticity to aged vocal folds, an intervention that might increase HA and decrease collagen production from aged vocal fold fibroblasts would appear to be a potentially useful approach. Our previous in vitro study has revealed that basic fibroblast growth factor (bFGF) consistently stimulates HA production and decreases collagen production from aged rat vocal fold fibroblasts. The present in vivo study examined the effects of intracordal injection of bFGF into aged rats' vocal folds in terms of restoration of HA and collagen distribution in the lamina propria. We injected bFGF transorally into the lamina propria of (unilateral) vocal folds. The injection was repeated 4 times weekly, and rats were painlessly sacrificed 1 week, 1 month, and 2 months after the final injection. Histologic examination revealed that bFGF significantly increased the HA content of the lamina propria up to 2 months, but showed no effect on collagen, even after 2 months. Because it might take longer for excessive collagen to be degraded, further studies are necessary to clarify the long-term effect on collagen. A drug delivery system for bFGF also needs to be developed to maximize its effect in the future. The present study suggested at least a positive effect of bFGF in restoring the HA content in the aged vocal fold lamina propria.

Sign in / Sign up

Export Citation Format

Share Document