Vocal Fold Mass Research Articles

Neural network-based estimation of biomechanical vocal fold parameters.

Vocal fold (VF) vibrations are the primary source of human phonation. High-speed video (HSV) endoscopy enables the computation of descriptive VF parameters for assessment of physiological properties of laryngeal dynamics, i.e., the vibration of the VFs. However, underlying biomechanical factors responsible for physiological and disordered VF vibrations cannot be accessed. In contrast, physically based numerical VF models reveal insights into the organ's oscillations, which remain inaccessible through endoscopy. To estimate biomechanical properties, previous research has fitted subglottal pressure-driven mass-spring-damper systems, as inverse problem to the HSV-recorded VF trajectories, by global optimization of the numerical model. A neural network trained on the numerical model may be used as a substitute for computationally expensive optimization, yielding a fast evaluating surrogate of the biomechanical inverse problem. This paper proposes a convolutional recurrent neural network (CRNN)-based architecture trained on regression of a physiological-based biomechanical six-mass model (6 MM). To compare with previous research, the underlying biomechanical factor "subglottal pressure" prediction was tested against 288 HSV ex vivo porcine recordings. The contributions of this work are two-fold: first, the presented CRNN with the 6 MM handles multiple trajectories along the VFs, which allows for investigations on local changes in VF characteristics. Second, the network was trained to reproduce further important biomechanical model parameters like VF mass and stiffness on synthetic data. Unlike in a previous work, the network in this study is therefore an entire surrogate of the inverse problem, which allowed for explicit computation of the fitted model using our approach. The presented approach achieves a best-case mean absolute error (MAE) of 133 Pa (13.9%) in subglottal pressure prediction with 76.6% correlation on experimental data and a re-estimated fundamental frequency MAE of 15.9 Hz (9.9%). In-detail training analysis revealed subglottal pressure as the most learnable parameter. With the physiological-based model design and advances in fast parameter prediction, this work is a next step in biomechanical VF model fitting and the estimation of laryngeal kinematics.

Vocal Fold Paresis and Voice Outcomes following Vocal Fold Mass Excision.

To correlate the surgical results of vocal fold mass excision with pre-operative existence of vocal fold paresis. Data were collected on 66 patients who underwent excision of benign vocal fold masses from 2015 to 2020. The pre- and post-operative strobovideolaryngoscopy (SVL) examinations for all patients included were evaluated blindly by three otolaryngologists using THE Voice-Vibratory Assessment with Laryngeal Imaging (VALI) Form for scar severity, mucosal wave, free edge contour, glottal closure, and phase closure. The success of mass excision surgery was determined based on the presence of the following criteria post-operatively: 1) improved mucosal wave motion 2) improved phase closure or glottic closure 3) improved free edge contour and 4) lack of worsening of vocal fold scar severity. Surgery was considered successful if 3 or 4 criteria were met, partially successful if 1 or 2 criteria were met, and unsuccessful if no criteria were met. The percent recruitment of the thyroarytenoid, posterior cricoarytenoid (PCA), and cricothyroid muscles were used evaluated the severity of paresis as mild (70-99% recruitment), moderate (40-60% recruitment), or severe (0-39% recruitment). VHI-10 scores were used as subjective measures of pre- and post-operative voice. Sixty-six patients (26 male, 40 female) were included in this study, with a mean age of 37.25 ± 16.6 (range 18-78). Twelve patients had no evidence of VF paresis noted during the initial clinical evaluation; and 52 patients had paresis and had undergone laryngeal EMG. 81% of these patients had mild paresis, 12.8% had moderate paresis, and 5.8% had severe paresis. Based on pre- and post-operative strobovideolaryngoscopy, there was improvement in mucosal wave in 44.9% of cases, improvement of phase or glottic closure in 85.4% of cases, improved free edge contour in 95.5% of cases, and worsening of scar in 38.5% of cases. 39.6% of surgeries were fully successful, 33.3% of surgeries were partially successful, and 27.1% were not successful. There was a significant correlation between female gender and vocal fold paresis (P=0.048). Paresis severity did not correlate with complete or partial surgical success (P=0.956), pre-operative VHI-10 scores (P=0.519), post-operative VHI-10 scores (P=0.563), or strobovideolaryngoscopy parameters. Unilateral and bilateral paresis did not correlate with any other parameter of surgical success (P >0.05). This study suggests that there is no correlation between pre-operative vocal fold paresis and voice outcomes after mass excision surgery, that the majority of mass excision surgeries (72.9%) are successful based on improvement in stroboscopic parameters, and that the proportion of patients with moderate and severe paresis is consistent across all laryngeal nerves.

Gender Differences in Benign Vocal Fold Mass Treatment

Abstract: Benign vocal fold masses are seen commonly in amateur and professional voice users. Data shows that patients presenting with similar benign vocal fold masses are treated with different modalities at different rates based on their gender identity and patient preference. Professional and amateur voice users are also found to have different rates of treatment. Singing teachers have unique longitudinal relationships with their students. Knowledge of the effects of benign focal fold masses on the voice and glottic function along with treatment modalities can help singing teachers provide extra surveillance to students who may be at risk of suboptimal treatment. This article focuses on benign vocal fold mass classification, causes, symptoms, medical diagnosis, and treatment relevant to singing teachers with respect to the patient’s gender. Professional voice use is discussed as a potentially confounding factor to seeking treatment of benign vocal fold masses in the context of gender differences.

Value of high-speed videoendoscopy as an auxiliary tool in differentiation of benign and malignant unilateral vocal lesions

PurposeThe study aimed to assess the relevance of objective vibratory parameters derived from high-speed videolaryngoscopy (HSV) as a supporting tool, to assist clinicians in establishing the initial diagnosis of benign and malignant glottal organic lesions.MethodsThe HSV examinations were conducted in 175 subjects: 50 normophonic, 85 subjects with benign vocal fold lesions, and 40 with early glottic cancer; organic lesions were confirmed by histopathologic examination. The parameters, derived from HSV kymography: amplitude, symmetry, and glottal dynamic characteristics, were compared statistically between the groups with the following ROC analysis.ResultsAmong 14 calculated parameters, 10 differed significantly between the groups. Four of them, the average resultant amplitude of the involved vocal fold (AmpInvolvedAvg), average amplitude asymmetry for the whole glottis and its middle third part (AmplAsymAvg; AmplAsymAvg_2/3), and absolute average phase difference (AbsPhaseDiffAvg), showed significant differences between benign and malignant lesions. Amplitude values were decreasing, while asymmetry and phase difference values were increasing with the risk of malignancy. In ROC analysis, the highest AUC was observed for AmpAsymAvg (0.719; p < 0.0001), and next in order was AmpInvolvedAvg (0.70; p = 0.0002).ConclusionThe golden standard in the diagnosis of organic lesions of glottis remains clinical examination with videolaryngoscopy, confirmed by histopathological examination. Our results showed that measurements of amplitude, asymmetry, and phase of vibrations in malignant vocal fold masses deteriorate significantly in comparison to benign vocal lesions. High-speed videolaryngoscopy could aid their preliminary differentiation noninvasively before histopathological examination; however, further research on larger groups is needed.

Control of chaotic vibrations in lumped mass models of the vocal folds

Lumped mass models have been widely used as low-dimensional systems to better understand the physics underlying human phonation. This is a highly non-linear process in which subglottal flow emanating from the lungs excite self-oscillations of the vocal folds. Consequently, a pulsating volume velocity is established that produces acoustic waves, which then travel through the vocal tract and are released from the mouth as voice. The self-oscillations of the vocal folds may be affected by many undesirable factors like the presence of polyps, lateral paralyses, excessive subglottal pressure, etc., and transition from regular to chaotic motion. This gives rise to abnormal phonation. In this work, we explore the theoretical possibility of adding smart materials to vocal fold lumped mass models. The smart material must be such that its damping can be dynamically modified. By proper tuning, one can establish a feedback control mechanism that restores chaotic vocal fold oscillations to normality. This would constitute the essence of a pacemaker for phonation.

The Safety and Efficacy of the 445-nm Blue Laser for Operative Management of Benign Nonvascular Laryngeal Lesions

Adult voice center patients who underwent surgical intervention for vocal fold (VF) mass, VF scar, laryngeal stenosis, laryngeal web, or Reinke's edema were included in this retrospective study. Outcomes were compared to those achieved when traditional treatment modalities were used, including cold steel, CO2 laser, potassium-titanyl-phosphate (KTP) laser, and coblator. Strobovideolaryngoscopy footage was evaluated using a previously described model at four time points: postoperative visit #1: 1-14 days, postoperative visit #2: 30-60 days, postoperative visit #3: 61-365 days, postoperative visit #4: >365 days. Eighty cases using the blue laser and 153 controls (n=78 cold steel, n=51 KTP laser, n=22 CO2 laser, n=2 coblator) were included in this study. Procedures performed using blue laser included VF mass excision (n=45), VF scar reduction (n=16), laryngeal stenosis resection/repair (n=25), laryngeal web excision (n=7), and reduction of Reinke's edema (n=1). On postoperative strobovideolaryngoscopy examination, the surgical objective score did not differ significantly between the blue laser cohort and all controls at any postoperative visit. VF edema did not differ significantly between the blue laser cohort and all controls at any postoperative visit. VF hemorrhage scores were significantly lower in the blue laser cohort compared to all controls at the first postoperative visit, but hemorrhage had resolved almost entirely by the second postoperative visit in all groups. Postoperative VF stiffness was worse in the blue laser group at the third postoperative visit compared to controls, but both groups had improved to similar levels by the fourth postoperative visit. The rate of lesion recurrence (24.29% versus 17.19%) did not differ significantly between the blue laser cohort and controls on multivariate analysis (Odds ratio [OR]=1.081 [0.461-2.536]). The complication rate (12.50% versus 10.46%) did not differ significantly between the blue laser cohort and all controls on multivariate analysis (OR=0.992 [0.375-2.624]). The blue laser was associated with a lower rate of revision surgery (30.00% versus 34.64%) on multivariate analysis (OR=0.380 [0.168-0.859]). The 445-nm blue laser is safe and effective for the management of benign laryngeal lesions. It has efficacy and safety similar to those of traditional treatment modalities (including cold steel, CO2 laser, and KTP laser). Use of the blue laser may lead to lower rates of early postoperative hemorrhage and revision surgery. No adverse effects attributed directly to the use of the blue laser were observed in this study. Further research is encouraged to confirm or refute these findings.

The Estill Voice Model: A paradigm for voice training and treatment

For over 40 years, the Estill Voice Model (EVM) has defined voice quality according to movement of anatomy and physiology. EVM addresses the daunting degrees of freedom issue in voice motor control by isolating Craft of voice production from Artistry and Performance Metaphysics. The EVM proposes an integrated implicit-explicit approach for voice motor learning that flows through all training and therapy protocols. Implicit instructions include auditory-perceptual prompts (e.g., quack like a duck to produce “twang”) and explicit prompts train physiologic conditions of the vocal anatomy correlated with the voice quality (e.g., narrow your aryepiglottic sphincter to produce “twang”). Estill exercises address power, source, and filter properties of voice production, and include narrowing the aryepiglottic sphincter for “ring” in opera and belt and for increased power in hypofunctional voices, and varying vocal fold mass for register shifts and optimizing contact for hyperfunctional voices. Patients learn to feel, see, and hear the voice via multiple feedback modes including hand gestures, magnitude estimation of bodily kinesthetic effort, visual acoustic cues in real-time spectral analysis programs. This presentation will highlight objective measurement science and clinical evidence for using Estill exercises in treatment for all voices, from the novice speaker to the expert performer.

Duration of vocal effects due to water resistance therapy

There are only few data about effects of semi-occluded vocal tract exercises on vocal fold oscillation patterns in vivo. Furthermore, it has not yet been clarified for how long these effects last. Material: 16 subjects (8 non-pathological and 8 with vocal fold mass lesion) were asked to sustain a phonation on the vowel /i/. During phonation, the subjects were simultaneously recorded with transnasal high speed videoendoscopy (HSV, 20.000 fps), electroglottography, and audio signals. After that, these subjects performed a Water Resistance Therapy (WRT) for 10 min (tube 30 cm, 9 mm diameter, 5 cm below surface). Repeated measurements of sustained phonation were performed 0, 10, and 30 min after exercising. The data showed strong inter-individual differences concerning the courses of the different measures after WRT. For non-pathological voices, directly after WRT there was a lowering of the Glottal-Area-Waveform derived Period-Perturbation -Quotient, a lowering of the closing quotient. For pathological voices, however, such a decrease was not observable. Five minutes after the exercise such effect was not observable any more. WRT showed strong inter-individual effects in the courses of the evaluated measures. General tendencies of some measures directly after the intervention showed a brief effect of only a few minutes.

Misdiagnosis of Vocal Fold Nodules

Benign vocal fold masses (BVMs) include nodules, polyps, cysts, and other pathology. Nevertheless, some otolaryngologists and other physicians utilize "vocal fold nodules" as an umbrella diagnosis for vocal fold masses. Patients subsequently evaluated by a laryngologist are found to have a different vocal fold mass, which often has a different prognosis and treatment plan compared to nodules. The purpose of this study was to investigate the rate at which vocal fold nodules are misdiagnosed. Adult voice patients who presented to our voice center having been evaluated elsewhere by an otolaryngologist and diagnosed with vocal fold nodules, or prenodules, were included in this retrospective study. Strobovideolaryngoscopy (SVL) footage from each patient's first visit or prior to any treatment at our center was compiled and de-identified. Three blinded physician raters evaluated the videos to determine if the mass(es) was/were nodules on a binary scale, with 1 indicating a nodule. If the mass was not a nodule (0), the raters were asked to identify it based on a list of five different mass types. There were 56 cases (11 male and 45 female) included in the retrospective cohort. The average age was 38±14.8 with a range of 11-65. Reliability between all raters was fair (κ=0.3). Individually raters 1 and 2 had very good reliability (κ=1) and rater 3 had good reliability (κ=0.6). In 100% of cases, two raters agreed that none of the masses were nodules. Only one rater identified two masses as vocal fold nodules, indicating that at least 97% of cases were not vocal fold nodules and had been misdiagnosed. The most frequently identified mass and the most frequently agreed upon mass by all raters was vocal fold cyst or pseudocyst, followed by fibrous mass. Only one rater was unable to identify the mass type in some cases (n=7). Vocal fold nodules are frequently misdiagnosed. Proper identification of vocal fold masses requires high levels of expertise and SVL. Since treatment of BVMs varies with mass type, accurate diagnosis is essential.

Incorporating a gender expansive perspective into speech science pedagogy

This talk challenges the assumption of a traditional gender binary in speech science pedagogy. We first define and operationalize notions of sex and gender as they relate to speech communication. We will broadly consider acoustic properties that relate to anatomical differences across humans (such as vocal tract length and vocal fold mass) and acoustic properties that relate to socio-phonetic variation. We challenge the notion that anatomical differences are the only source of speech variability across gender categories. We discuss problems in the literature related to how speakers and listeners are categorized (typically either as binary male/female or binary man/woman with the assumption of cisgender gender identity). We move beyond the binary assumption of the ways that “males” and “females” speak by demonstrating speakers’ agency in constructing linguistic styles that are rich in social information and that convey nuanced identities. We highlight the variability in listeners’ perception of speaker gender and consider potential sources of this variability. Attendees will be provided with instructional tools that incorporate gender diversity into the speech science curriculum and that can be used in classroom discussions and activities.

Auditory-perceptual Parameters as Predictors of Voice Acoustic Measures

Much research has examined the relationship between perceptual and acoustic measures. However, little is known about the prediction values of perceptual measures on an acoustic parameter. This study utilized simulated and disordered voice samples to investigate the prediction values of breathiness, roughness, and strain ratings on the selection of some time-based and spectral-based measures of voice quality. This study retrospectively analysed two sets of precollected data. The experimental data had been collected from nine trained speakers manipulating false vocal fold activity, true vocal fold mass, and larynx height. The voice-disordered data had been extracted from a clinical database for 68 patients with muscle tension voice disorders (MTVD). Both data sets had been perceptually rated for breathiness, roughness, and strain. Voice samples (prolonged vowel /ɑ/ and Rainbow Passage readings) had undergone acoustic analysis using Praat for harmonics-to-noise ratio (HNR) and the program "Analysis of Dysphonia in Speech and Voice" (ADSV) for cepstral peak prominence (CPP), Cepstral/Spectral Index of Dysphonia (CSID), and Low/High spectral ratio (L/H ratio). Perceptual parameters were regressed against these acoustic measures to test their prediction values. Reliability data showed satisfactory intra- and inter-reliability of perceptual ratings for both data sets. Breathiness significantly predicted CPP (both vocal tasks) and CSID (Rainbow Passage) in experimental data and predicted all the acoustic measures in MTVD data. Roughness significantly predicted HNR, CPP, and CSID in experimental data, and CPP (Rainbow Passage) and CSID (both vocal tasks) in MTVD data. Strain (both vocal tasks) significantly predicted L/H ratio in both data sets. Breathiness ratings predicted selection of HNR, CPP and CSID; roughness ratings predicted selection of CPP and CSID, and strain ratings predicted L/H ratio.

An Introduction to Vocal Fold Masses

Vocal fold masses are common, and singing teachers should be familiar with their nature and implications. This article reviews common abnormalities that occur on the vocal folds including nodules, cysts, polyps, scar, vascular abnormalities, granulomas and other pathology. Each requires different management. Guidance is given so that singing teachers understand the nature of different vocal fold masses and basic treatment guidelines. This will help them advise their students as to whether treatment recommendations seem reasonable.

The Association of Objective Voice Measurement With Treatment of Vocal Fold Masses

Objectives/Hypothesis To determine the predictive value of objective voice measurements in patients with vocal fold masses for receiving medical or surgical management. Study Design Retrospective chart review. Methods Patients presented from January 2015 through March 2020 and diagnosed with vocal fold mass. Objective voice measurements studied were average fundamental frequency, jitter percent, relative average perturbation, shimmer percent, noise to harmonic ratio, standard deviation of fundamental frequency, maximum phonation time, and S:Z ratio. Non-parametric Mann Whitney U test, chi square and fisher exact test were used. Results Ninety-six patients (48 male and 48 female) were included. Males who received surgical management (MS) had significantly higher jitter percent (1.82 ± 1.34) than males who received medical management (MM) (1.16 ± 19.21), P = 0.02. Furthermore, MS had significantly higher relative average perturbation percent (1.06 ± 0.78) than MM (0.68 ± 0.57), P = 0.03. Females who received surgical management had significantly lower shimmer percent (3.74 ± 2.88) than females who received medical management (4.66 ± 2.42), P = 0.01. Univariate significance was found in some female confounding variables. A logistic regression model did not show significance. Conclusion Males with high jitter percent and relative average perturbation are more likely to receive surgical management for vocal fold masses. Females with lower shimmer percent are more likely to have surgical management of vocal fold masses when compared to the medical management group. Objective voice measures did not show significant predictive value when controlled for confounding variables. To determine the predictive value of objective voice measurements in patients with vocal fold masses for receiving medical or surgical management. Retrospective chart review. Patients presented from January 2015 through March 2020 and diagnosed with vocal fold mass. Objective voice measurements studied were average fundamental frequency, jitter percent, relative average perturbation, shimmer percent, noise to harmonic ratio, standard deviation of fundamental frequency, maximum phonation time, and S:Z ratio. Non-parametric Mann Whitney U test, chi square and fisher exact test were used. Ninety-six patients (48 male and 48 female) were included. Males who received surgical management (MS) had significantly higher jitter percent (1.82 ± 1.34) than males who received medical management (MM) (1.16 ± 19.21), P = 0.02. Furthermore, MS had significantly higher relative average perturbation percent (1.06 ± 0.78) than MM (0.68 ± 0.57), P = 0.03. Females who received surgical management had significantly lower shimmer percent (3.74 ± 2.88) than females who received medical management (4.66 ± 2.42), P = 0.01. Univariate significance was found in some female confounding variables. A logistic regression model did not show significance. Males with high jitter percent and relative average perturbation are more likely to receive surgical management for vocal fold masses. Females with lower shimmer percent are more likely to have surgical management of vocal fold masses when compared to the medical management group. Objective voice measures did not show significant predictive value when controlled for confounding variables.

Assessment of Vocal Fold Stiffness by Means of High-Speed Videolaryngoscopy with Laryngotopography in Prediction of Early Glottic Malignancy: Preliminary Report.

Simple SummaryThe method described in our manuscript can help to objectively assess the vibration of each vocal fold using larygotopographic analysis of high-speed videoendoscopy (HSV) recordings. We have developed image processing and analysis procedures to detect vocal fold regions in HSV films and quantitatively analyze their shape and kinematics. We proposed the term Stiffness Asymmetry Index which can provide valuable information on the texture and kinematic properties of individual vocal fold tissues, which can be important in the diagnosis of early glottis cancer. Our study showed that a low value of SAI indicated large, non-vibrating vocal fold areas, characteristic of infiltrative lesions such as invasive carcinoma. This important clinical information can help to assess the depth of vocal fold invasion before direct histologic examination and discriminate benign from malignant lesions.One of the most important challenges in laryngological practice is the early diagnosis of laryngeal cancer. Detection of non-vibrating areas affected by neoplastic lesions of the vocal folds can be crucial in the recognition of early cancerogenous infiltration. Glottal pathologies associated with abnormal vibration patterns of the vocal folds can be detected and quantified using High-speed Videolaryngoscopy (HSV), also in subjects with severe voice disorders, and analyzed with the aid of computer image processing procedures. We present a method that enables the assessment of vocal fold pathologies with the use of HSV. The calculated laryngotopographic (LTG) maps of the vocal folds based on HSV allowed for a detailed characterization of vibration patterns and abnormalities in different regions of the vocal folds. We verified our methods with HSV recordings from 31 subjects with a normophonic voice and benign and malignant vocal fold lesions. We proposed the novel Stiffness Asymmetry Index (SAI) to differentiate between early glottis cancer (SAI = 0.65 ± 0.18) and benign vocal fold masses (SAI = 0.16 ± 0.13). Our results showed that these glottal pathologies might be noninvasively distinguished prior to histopathological examination. However, this needs to be confirmed by further research on larger groups of benign and malignant laryngeal lesions.

Is there Really a Lump in My Throat? The Incidence and Implication of Vocal fold Abnormalities in Patients Presenting with Globus

To identify the prevalence of vocal fold abnormalities in patients with a primary complaint of globus sensation. Secondly, to determine the relationship between globus, vocal fold abnormality, and patient-reported quality of life questionnaire score. Retrospective chart review. A retrospective chart review was performed to identify all new patients evaluated at a tertiary academic care laryngology practice between January 2018 and December 2018 presenting with a chief complaint of globus. Variables of interest include age, gender, laryngeal symptoms, self-reported quality-of-life questionnaire results, and laryngostroboscopy findings. Questionnaires selected for this investigation include the reflux symptom index (RSI), eating assessment tool-10 (EAT-10), and voice handicap index-10 (VHI-10). Two hundred twenty-eight subjects with an average age of 54 ±17 years, were categorized based on one of three laryngostroboscopic findings: absence of vocal fold abnormality, vocal fold paresis/paralysis (motion abnormality), or a vocal fold mass lesion. Fifty percent of patients reporting globus had a normal laryngeal exam, and 50% had a mass lesion or motion abnormality. Twenty five percent had vocal fold motion abnormality (paresis, paralysis, or supraglottic squeeze); 19% had a mass lesion; and 3% had both a lesion and motion abnormality. The average self-reported survey scores were compared among the three groups. Patients with dysphonia had a significantly higher VHI-10 (P=0.00), and a significantly higher RSI (P= 0.00) than those without dysphonia. Those patients with dysphagia had significantly higher EAT-10 (P=0.00) and RSI (P=0.02) scores than those who did not have dysphagia. Patients with vocal fold motion abnormality had significantly higher VHI-10 than those with normal vocal fold mobility (P=0.02) CONCLUSIONS: Identifying the etiology of globus presents a significant challenge to laryngologists. Data presented here suggest that vocal fold abnormalities may contribute to the sensation of globus and should therefore be considered in the differential when managing these patients.

Controlling chaotic oscillations in a symmetric two-mass model of the vocal folds

Human phonation is a highly non-linear process in which subglottal flow emanating from the lungs induces self-oscillations of the vocal folds. In normal conditions, this results in the generation of a regularly pulsating volume velocity that becomes the source of acoustic waves, which once modulated by the vocal tract, get emitted outwards as voice. However, vocal fold oscillations can become chaotic under many circumstances. For instance, even in the case of healthy symmetric vocal folds, an excess value of the subglottal pressure can trigger chaotic motion. In this paper, we derive a chaos control strategy for a two-mass model of the vocal cords to revert the situation and render the motion regular again. The approach relies on slightly altering the system energy to move it to a stable state. Given that no external control forces can be applied to the vocal cords, it is proposed to add a third mass to the original two-mass model, which is assumed to be made of an ideal smart material. The mass of the smart material is presumed negligible in comparison to the two masses of the vocal folds model, but its damping and stiffness can be tuned to evolve with time. For a fixed subglottal pressure for which the motion is chaotic, it is shown how periodicity can be recovered using adequate damping laws, by either attaching the smart material onto the larger vocal fold mass or onto the smaller one. For the latter, chaos control turns to be more difficult and the damping of the smart material has to quickly vary with time. On the other hand, given that the subglottal pressure would rarely be constant in a real situation, we also introduce a damping law to avoid chaotic motion as the subglottal pressure augments or diminishes. Finally, it is shown that control can not only be achieved by acting on the damping of the smart material but also on its stiffness. A stiffness law to prevent chaotic oscillations and get a healthy pulsating volume velocity is therefore implemented. A brief discussion on the mid-long term potential of the presented solution for practical cases is included.

Vocal fold myxoma: a case report and review of current literature

BackgroundVocal fold myxoma is a rare mesenchymal tumor with unknown exact etiology. The aim of this report is to review current literature on demographic and clinical features of vocal fold myxomas in order to increase awareness among otorhinolaryngologists on management of this rare vocal fold pathology.Case presentationWe report a case of a 46-year-old female teacher presented with 1 year history of progressive dysphonia with no airway obstructive or constitutional symptoms. Flexible laryngoscopy revealed a polypoid mass at the anterior two thirds of the left vocal fold. We proceeded with endolaryngeal microsurgery, where a left vocal fold mass with prominent overlying blood vessels was incompletely excised due to poor plane, in an attempt to prevent injury to vocal ligament. The histopathological findings were consistent with myxoma. No evidence of recurrence was noted at 2 months postoperatively.ConclusionsVocal fold myxoma should be considered as a differential diagnosis of vocal fold pathology clinically resembling vocal fold polyp, especially in older male adults. Complete excision with removal of a rim of surrounding tissue is the gold-standard treatment to prevent recurrence. If diagnosis is uncertain, intraoperative frozen section can be performed to ensure margins are free from tumor. Life-long follow-up is recommended in incomplete excision of tumor.

Gender Differences in Vocal Fold Mass Treatment

The purpose of the study was to examine gender-related differences in benign vocal fold mass treatment. Adult patient with vocal fold mass diagnosed on strobovideolaryngoscopy examination were reviewed retrospectively. Patient demographics, past medical history, laboratory data, and examination findings during the initial visit and at follow-up were collected. The duration of voice therapy and the prevalence of surgery were analyzed for males and females. One hundred and fifty-eight patients (76 male and 82 female) were included. The percentage of professional voice users differed significantly between males and females. Vocal folds of females had a higher percent of reactive masses present. Females were also more likely to have a pseudocyst. Vocal folds of males showed a higher percent of masses of unspecified category on strobovideolaryngoscopy examination. A significantly greater proportion of females had abnormal high shimmer values, and abnormal low maximum phonation time; and a significantly greater proportion of females compared to males chose to participate in voice therapy. The average number of voice therapy sessions for males did not differ, nor did duration of voice therapy. A similar proportion of males and females underwent surgical mass excision. The treatment plan completed differed significantly between males and females with a higher percentage of males choosing to receive no treatment. For 45.54% of males and 59.70% of females the treatment plan consisted of voice therapy only. For 33.33% of males and 37.31% of females, the treatment plan included both voice therapy and surgery. Although gender was the strongest predictor for participation in voice therapy, professional voice uses also predicted participation in voice therapy in both men and women significantly. Professional singing in particular was not a significant predictor for participation in voice therapy. Males were significantly more likely than females to be lost to follow-up before treatment outcome could be assessed CONCLUSION: More females than males were found to have pseudocysts while more males than females had unspecified masses. Females and professional voice users were more willing than males to utilize voice therapy. No difference was found between males and females who decided to have surgery. The best treatment regimen for vocal fold mass is a combination of voice therapy and surgery, when necessary, but gender-specific differences merit further research as well as reconsideration of therapy approaches and strategies to optimize patient compliance.

Evaluation of Size, Laterality, and Location of Unilateral Vocal Fold Lesions on Voice Quality

The presence of a vocal fold mass implies high mechanical stress at the vocal fold base during vibration and an impaired glottic closure. However, evidence about its potential effects on diagnostic tools used in voice evaluation is lacking. We aimed to evaluate the impact of the location, laterality, and size of a unilateral unique vocal fold lesion on patient self-assessment questionnaires, acoustic-aerodynamic voice measures, and perceptual voice evaluation (GRBAS scale). A retrospective chart review involving patients with a diagnosis of a unique unilateral vocal fold lesion and a complete voice evaluation was performed. A total of 58 patients were enrolled and demographics, characteristics of the vocal fold lesion (size, laterality, and location), self-assessment questionnaires, acoustic-aerodynamic measures, and perceptual evaluation (GRBAS scale) were analyzed. Pearson correlation and ANOVA analysis were completed to evaluate the correlation between the clinical characteristics of the vocal fold mass and self-assessment questionnaires, and to compare the level of significance for the differences between the continuous variables between groups of patients once stratified according to the location or laterality of the vocal fold mass. Glottal Function Index was found to correlate with the location of the vocal fold mass (P < 0.05), however, no correlation was found when evaluating the Reflux Symptom Index or the Voice Handicap Index (P > 0.05). Patients with a lesion located in the anterior-middle 2/3 of the vocal fold were found to have a higher mean Glottal Function Index and (G) component of the GRBAS scale (P < 0.05). No differences were observed when analyzing the remaining self-assessment questionnaires or the acoustic-aerodynamic voice measures according to size, location, or laterality of the vocal fold lesion (P > 0.05). The size and location of unilateral vocal fold lesions were found to have no effect on the majority of measures analyzed in this study. This is the first study we know of to assess the effect that laterality of the vocal fold lesion may have on the self-assessment questionnaires, audio-perceptual, and acoustic-aerodynamic measures included in this study. Our study found no significant differences in regard to laterality. This may indicate that other factors (eg, stiffness of lesion, amount of extraneous muscle tension, etc) could have more of an impact on audio-perceptual, self-assessment questionnaires, and acoustic-aerodynamic measures. Further research with larger cohort sizes and possibly prospective analysis is needed.

Assessment of Postoperative Pain and Opioid Consumption Following Laryngeal Surgery: A Pilot Study

Adult voice center patients who had recently undergone laryngeal surgery were included in this retrospective review. Tylenol #3 had been prescribed for all patients for pain management and they had been instructed to take additional over-the-counter acetaminophen as needed. In the senior author's (RTS) practice, patients are asked routinely to report pain severity and analgesic use during postoperative visits. All patients who had this information available were included in the cohort. Opioid medication consumed, over-the-counter medication consumed, and pain level (scale of 0-10 with 10 being most severe) were analyzed over the first week postoperatively. There were 43 patients (19 male, 24 female) included in the retrospective cohort (average age = 46.8 ± 18.6, range = 18-82). Procedures performed included vocal fold mass excision (48.8%), type I thyroplasty (27.9%), laser vaporization of vascular lesions (11.6%), laser stenosis resection (9.3%), and VF medialization injection with abdominal fat harvest (7.0%). Overall, voice surgery patients reported mild to moderate pain (2.1-4.7 out of 10). An average of 13.2 ± 2.8 T3 tablets were prescribed for pain management (range = 10-20), and no patient required more T3 tablets than the number provided. Sixteen patients (37.2%) supplemented or substituted their T3 medication for it with OTC acetaminophen. No patients used non-steroidal anti-inflammatory drugs (NSAIDs) for supplemental pain management. Consumption of both T3 pain medication (r = 0.444) and OTC acetaminophen (r = 0.274) was correlated significantly with postoperative pain severity (P < 0.001). When stratified by type of surgical procedure performed, one-way ANOVA (F = 2.749, P = 0.043) and post-hoc Games-Howell test revealed that the patients who underwent type I thyroplasty reported a significantly higher (P = 0.041) pain severity score than patients who underwent vocal fold mass excision (4.7 versus 2.1, respectively). No significant differences in pain severity existed between other procedures (P > 0.05). There were no significant differences between type of procedure performed for number of T3 tablets prescribed, number of T3 tablets taken, or number of OTC tablets taken (P > 0.05). Younger age was correlated significantly with a higher number of OTC tablets consumed (r = -0.316, P = 0.039). Women consumed more OTC pain medications than men. Most patients in this study reported mild to moderate postoperative pain. Adequate pain management was achieved using less pain medication tablets than the number prescribed. Type I thyroplasty was associated with more severe pain than other surgeries. Women used more OTC pain medications than men with no significant difference in reported pain level.