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1.
Laryngoscope ; 2024 Aug 08.
Article in English | MEDLINE | ID: mdl-39115162

ABSTRACT

OBJECTIVE: Vocal fold scar and sulcus pose significant treatment challenges with no current optimal treatment. Platelet-rich plasma (PRP), an autologous concentration of growth factors, holds promise for regenerating the superficial lamina propria. This study aims to evaluate the potential benefits of serial PRP injections on mucosal wave restoration and vocal function. METHODS: In a prospective clinical trial across two institutions, patients with vocal fold scar underwent four serial PRP injections, one month apart. Blinded independent laryngologists and expert listeners used pretreatment and one-month post-fourth injection videostroboscopy and CAPE-V assessments to evaluate mucosal wave and voice quality changes, respectively. Additionally, patient reported outcome measures (PROMs) were evaluated. RESULTS: In the study, 15 patients received 55 PRP injections without adverse effects. Eight patients (53.3%) had mild, three patients (20%) had moderate, and four patients (26.7%) had severe scar. There was an average reduction of 8.7 points in post-treatment VHI-10 scores (p = 0.007). The raters observed an improvement in post-treatment voice in 73.4% of cases, and CAPE-V scores showed a reduction of 18.8 points on average (p = 0.036). The videostroboscopic VALI ratings showed an improvement in mucosal wave rating from 2.0 to 4.0. On average, the raters perceived the post-PRP exams to be better in 56.7% of cases. CONCLUSIONS: PRP has been validated as a safe autologous option for treatment of vocal fold scar. While results for mucosal wave and voice quality varied, there was a consistent improvement in PROMs. LEVEL OF EVIDENCE: Level 3: Prospective cohort study, with blinded analysis Laryngoscope, 2024.

2.
Article in English | MEDLINE | ID: mdl-38988306

ABSTRACT

OBJECTIVE: The Risk Analysis Index (RAI) score is a screening tool to assess patient frailty. It has been shown to be predictive of postoperative outcomes and mortality in orthopedic, urologic, and neurosurgical patient populations. We sought to evaluate the predictive ability of RAI score for surgical outcomes in an otolaryngology patient population. STUDY DESIGN: Retrospective study. SETTING: Academic tertiary medical center. METHODS: A retrospective study was conducted of adult patients undergoing otolaryngology surgery at a tertiary medical care center over 21 months. Patients were sent electronic RAI survey questionnaires via direct messaging, which was completed prior to surgery. Endpoint data were analyzed, including demographics, RAI score, and patient outcome data. Univariate analysis, ROC curves, and predictive modeling were utilized. RESULTS: A total of 517 patients responded to the RAI questionnaire, resulting in a 59.6% response rate. Mean RAI score was 21.38 ± 11.83. Higher RAI scores were associated with increased 30-day readmissions (P < .0015), postoperative complications (P < .001), hospital length of stay (P < .001), and discharge with home health (P < .001). Predictive models for RAI score and postoperative outcomes were created, and a cutoff score of RAI = 30 was established to identify frail patients. CONCLUSION: We evaluated if RAI scoring predicted postoperative complications in an otolaryngology patient population. Increased RAI score is significantly associated with poorer surgical outcomes, including increased hospital length of stay, 30-day readmissions, and postoperative complications. We propose a predictive model with suggested RAI cutoff scoring for use in the otolaryngology surgical population.

3.
Laryngoscope ; 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38949061

ABSTRACT

INTRODUCTION: Myasthenia gravis (MG) is an autoimmune disease that affects the neuromuscular junction. MG patients may present de novo with primary otolaryngology complaints, including swallowing dysfunction. This study describes a range of unique presentations and rare diagnostic serologies, which have not previously been fully described. METHODS: A retrospective review was performed of all patients presenting with primary symptom of dysphagia and subsequently diagnosed with MG. Data collected included demographics, clinical presentation, swallow studies, serology, imaging, treatment, and response. RESULTS: Five patients met the inclusion criteria. Four endorsed dysphagia as primary complaint and one endorsed dysphagia and dysphonia. All patients underwent in-office swallow evaluations that showed vallecular or pyriform sinus residue. Three patients completed modified barium swallow studies that showed pharyngeal weakness and epiglottic dysfunction in all, and upper esophageal sphincter dysfunction in two. One patient with additional symptom of dyspnea was admitted and found to be in myasthenic crisis. Upon serologic evaluation, three patients were positive for acetylcholine receptor (AChR) antibodies only, one for muscle-specific-kinase (MuSK) antibodies only, and one for low density lipoprotein receptor-related protein 4 (LRP4) antibodies only. All patients received neurology evaluation and were treated with steroids, pyridostigmine, plasma exchange, or rituximab. In three patients with over 1 year follow-up, symptoms were significantly improved or resolved. CONCLUSION: MG is an important differential diagnosis in patients with unexplained pharyngeal dysphagia. While workup can include AChR antibody screening, in seronegative patients with persistent symptoms, additional testing for MuSK and LRP4 may lead to diagnosis and effective treatment. LEVEL OF EVIDENCE: Level 4 Laryngoscope, 2024.

4.
Head Neck ; 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-39077940

ABSTRACT

OBJECTIVES: Tracheoesophageal prosthesis (TEP) is a common method for post-laryngectomy speech rehabilitation. Despite its common use, some patients ultimately fail TEP rehabilitation. TEP dysfunction negatively affects quality of life due to poor voice quality and need for repeated interventions to restore TEP function. Occasionally, voice rehabilitation with TEP is completely unsuccessful. We performed a scoping review to characterize the main reasons for total TEP failure, in hopes of guiding selection of optimal TEP candidates. STUDY DESIGN: Scoping review using PubMed of all English language articles from 1990 to 2020 addressing causes of TEP failure. METHODS: This scoping review followed the population, intervention, comparison, outcome and study (PICOS) guidelines. Total TEP failure was defined as complete loss or abandonment of TEP voice or tract. A comprehensive search strategy using PubMed's MeSH subject headings and keywords was created. Causes and rates of failure were reviewed. RESULTS: Among 544 peer-reviewed journal articles reviewed for inclusion. Seventy articles met inclusion criteria, resulting in a total of 4928 TEP voice restoration patients for analysis. 15.2% of these patients had total TEP failure. The most common reasons for failure were dissatisfaction with voice (26.3%), leakage (17.9%), inadequate patient motivation (14.7%), comorbidities (14.2%), stoma problems (11.6%), and abandonment of TEP after dislodgement (10.6%). CONCLUSION: Common reasons for TEP failure included voice dissatisfaction, leakage, lack of patient motivation, patient comorbidities, and stoma problems. These factors should be considered when selecting candidates for TEP voice restoration.

5.
Laryngoscope ; 2024 Jul 30.
Article in English | MEDLINE | ID: mdl-39077971

ABSTRACT

Adult airway stenosis is a common condition treated in the otolaryngology clinic. Patients with high-grade, long-segment stenosis often fail endoscopic management. We describe the successful use of a hybrid resection and laryngotracheoplasty procedure that maximizes airway luminal patency in adults with successful decannulation. Laryngoscope, 2024.

6.
J Acoust Soc Am ; 155(3): 2139-2150, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38498507

ABSTRACT

Phonatory instabilities and involuntary register transitions can occur during singing. However, little is known regarding the mechanisms which govern such transitions. To investigate this phenomenon, we systematically varied laryngeal muscle activation and airflow in an in vivo canine larynx model during phonation. We calculated voice range profiles showing average nerve activations for all combinations of fundamental frequency (F0) and sound pressure level (SPL). Further, we determined closed-quotient (CQ) and minimum-posterior-area (MPA) based on high-speed video recordings. While different combinations of muscle activation favored different combinations of F0 and SPL, in the investigated larynx there was a consistent region of instability at about 400 Hz which essentially precluded phonation. An explanation for this region may be a larynx specific coupling between sound source and subglottal tract or an effect based purely on larynx morphology. Register transitions crossed this region, with different combinations of cricothyroid and thyroarytenoid muscle (TA) activation stabilizing higher or lower neighboring frequencies. Observed patterns in CQ and MPA dependent on TA activation reproduced patterns found in singers in previous work. Lack of control of TA stimulation may result in phonation instabilities, and enhanced control of TA stimulation may help to avoid involuntary register transitions, especially in the singing voice.


Subject(s)
Laryngeal Muscles , Vocalization, Animal , Animals , Dogs , Laryngeal Muscles/physiology , Phonation/physiology , Sound , Video Recording
7.
Laryngoscope ; 134(8): 3706-3712, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38544468

ABSTRACT

OBJECTIVES: Cervical chordoma is a rare, low-grade primary bone tumor occurring in the axial skeleton. Due to challenges in surgical exposure caused by anatomic location, patients may experience dysfunction in speech and swallowing. The objective of this study was to characterize speech and swallowing outcomes for patients undergoing surgical resection of cervical chordoma. Moreover, we detail in-depth two cases with similar initial presentations to compare prognostic factors and management strategies. METHODS: Eleven patients with histologically confirmed cervical chordoma treated between 1993 and 2020 were included in this retrospective case series. Outcomes measured included overall survival, disease-free survival, need for enteral feeds, as well as results of modified barium swallow study (MBSS) and fiberoptic laryngoscopy. RESULTS: The mean age at diagnosis was 55.9 years. The patient population was 81.8% male. Mean survival after diagnosis was 96 months. Four (36.4%) patients required post-operative MBSS and demonstrated aspiration. All four of these patients presented with tumors in the superior cervical spine and received surgeries utilizing anterior approaches. Of the four, 2 required enteral feeds long-term. Four (36.4%) patients endorsed dysphonia. One patient developed post-operative right vocal fold paresis. The remaining three patients experienced stable dysphonia pre- and post-operatively. Additionally, three (27%) patients required tracheostomy placement, two of which remained in place long-term. CONCLUSIONS: Dysphagia is a common side effect of cervical chordoma resection. It is associated with the use of an anterior approach during resection and with tumors located in the superior cervical spine. Patients with postoperative dysphagia should receive early multidisciplinary swallow rehabilitation. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:3706-3712, 2024.


Subject(s)
Cervical Vertebrae , Chordoma , Deglutition Disorders , Humans , Male , Middle Aged , Chordoma/surgery , Female , Retrospective Studies , Deglutition Disorders/etiology , Cervical Vertebrae/surgery , Aged , Adult , Postoperative Complications/etiology , Postoperative Complications/epidemiology , Deglutition , Spinal Neoplasms/surgery , Spinal Neoplasms/complications , Treatment Outcome
8.
Laryngoscope ; 134(3): 1327-1332, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37676064

ABSTRACT

INTRODUCTION: Asymmetry of vocal fold (VF) vibration is common in patients with voice complaints and also observed in 10% of normophonic individuals. Although thyroarytenoid (TA) muscle activation plays a crucial role in regulating VF vibration, how TA activation asymmetry relates to voice acoustics and perception is unclear. We evaluated the relationship between TA activation asymmetry and the resulting acoustics and perception. METHODS: An in vivo canine model of phonation was used to create symmetric and increasingly asymmetric VF vibratory conditions via graded stimulation of bilateral TA muscles. Naïve listeners (n = 89) rated the perceptual quality of 100 unique voice samples using a visual sort-and-rate task. For each phonatory condition, cepstral peak prominence (CPP), harmonic amplitude (H1-H2), and root-mean-square (RMS) energy of the voice were measured. The relationships between these metrics, vibratory asymmetry, and perceptual ratings were evaluated. RESULTS: Increasing levels of TA asymmetry resulted in declining listener preference. Furthermore, only severely asymmetric audio samples were perceptually distinguishable from symmetric and mildly asymmetric conditions. CPP was negatively correlated with TA asymmetry: voices produced with larger degrees of asymmetry were associated with lower CPP values. Listeners preferred audio samples with higher values of CPP, high RMS energy, and lower H1-H2 (less breathy). CONCLUSION: Listeners are sensitive to changes in voice acoustics related to vibratory asymmetry. Although increasing vibratory asymmetry is correlated with decreased perceptual ratings, mild asymmetries are perceptually tolerated. This study contributes to our understanding of voice production and quality by identifying perceptually salient and clinically meaningful asymmetry. LEVEL OF EVIDENCE: N/A (Basic Science Study) Laryngoscope, 134:1327-1332, 2024.


Subject(s)
Dysphonia , Voice , Humans , Animals , Dogs , Vibration , Speech Acoustics , Voice/physiology , Phonation/physiology , Acoustics , Perception
9.
Laryngoscope ; 134(3): 1249-1257, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37672673

ABSTRACT

INTRODUCTION: Analysis of medial surface dynamics of the vocal folds (VF) is critical to understanding voice production and treatment of voice disorders. We analyzed VF medial surface vibratory dynamics, evaluating the effects of airflow and nerve stimulation using 3D reconstruction and empirical eigenfunctions (EEF). STUDY DESIGN: In vivo canine hemilarynx phonation. METHODS: An in vivo canine hemilarynx was phonated while graded stimulation of the recurrent and superior laryngeal nerves (RLN and SLN) was performed. For each phonatory condition, vibratory cycles were 3D reconstructed from tattooed landmarks on the VF medial surface at low, medium, and high airflows. Parameters describing medial surface trajectory shape were calculated, and underlying patterns were emphasized using EEFs. Fundamental frequency and smoothed cepstral peak prominence (CPPS) were calculated from acoustic data. RESULTS: Convex-hull area of landmark trajectories increased with increasing flow and decreasing nerve activation level. Trajectory shapes observed included circular, ellipsoid, bent, and figure-eight. They were more circular on the superior and anterior VF, and more elliptical and line-like on the inferior and posterior VF. The EEFs capturing synchronal opening and closing (EEF1) and alternating convergent/divergent (EEF2) glottis shapes were mostly unaffected by flow and nerve stimulation levels. CPPS increased with higher airflow except for low RLN activation and very dominant SLN stimulation. CONCLUSION: We analyzed VF vibration as a function of neuromuscular stimulation and airflow levels. Oscillation patterns such as figure-eight and bent trajectories were linked to high nerve activation and flow. Further studies investigating longer sections of 3D reconstructed oscillations are needed. LEVEL OF EVIDENCE: N/A, Basic Science Laryngoscope, 134:1249-1257, 2024.


Subject(s)
Glottis , Vocal Cords , Animals , Dogs , Vocal Cords/physiology , Glottis/physiology , Phonation/physiology , Recurrent Laryngeal Nerve/physiology , Laryngeal Nerves/physiology , Vibration
11.
Otolaryngol Clin North Am ; 57(2): 343-352, 2024 Apr.
Article in English | MEDLINE | ID: mdl-37951721

ABSTRACT

Eosinophilic esophagitis is a male-predominant disease with presentations ranging from nonspecific feeding issues to dysphagia and food impaction. The currently proposed pathophysiology is a combination of genetics, allergens, and epithelial barrier impairment. Diagnosis is reliant on history, endoscopic examination, and biopsy. Recent guidelines recognize the role of concurrent gastroesophageal reflux disease. Treatment is based on 3 paradigms: diet, drugs, and dilation. Drug therapy has historically focused on topical corticosteroids; as of 2022, dupilumab was approved for targeted biologic therapy. Dilation is reserved for symptomatic and anatomic management. As this clinical entity is better understood, additional therapies will hopefully be developed.


Subject(s)
Deglutition Disorders , Enteritis , Eosinophilia , Eosinophilic Esophagitis , Gastritis , Gastroesophageal Reflux , Male , Humans , Eosinophilic Esophagitis/diagnosis , Eosinophilic Esophagitis/therapy , Otolaryngologists , Gastroesophageal Reflux/diagnosis , Deglutition Disorders/diagnosis , Deglutition Disorders/etiology , Deglutition Disorders/therapy
12.
Laryngoscope ; 134(1): 264-271, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37522475

ABSTRACT

OBJECTIVES: Despite gross anatomic and histologic differences between human and canine vocal folds, similar wave patterns have been described yet not fully characterized. We reconstructed vocal fold (VF) vibration in a canine hemilarynx and performed histologic examination of the same vocal fold. We demonstrate comparable wave patterns while exploring the importance of certain anatomic architectures. METHODS: An in vivo canine hemilarynx was phonated against a glass prism at low and high muscle activation conditions. Vibration was captured using high-speed video, and trajectories of VF medial surface tattooed landmarks were 3D-reconstructed. The method of empirical eigenfunctions was used to capture the essential dynamics of vibratory movement. Histologic examination of the hemilarynx was performed. RESULTS: Oscillation patterns were highly similar between the in vivo canine and previous reports of ex vivo human models. The two most dominant eigenfunctions comprised over 90% of total variance of movement, representing opening/closing and convergent/divergent movement patterns, respectively. We demonstrate a vertical phase difference during the glottal cycle. The time delay between the inferior and superior VF was greater during opening than closing for both activation conditions. Histological examination of canine VF showed not only a thicker lamina propria layer superiorly but also a distinct pattern of thyroarytenoid muscle fibers and fascicles as described in human studies. CONCLUSIONS: Histologic and vibratory examination of the canine vocal fold demonstrated human vocal fold vibratory patterns despite certain microstructural differences. This study suggests that the multilayered lamina propria may not be fundamental to vibratory patterns necessary for human-like voice production. LEVEL OF EVIDENCE: NA (Basic science study) Laryngoscope, 134:264-271, 2024.


Subject(s)
Vibration , Vocal Cords , Animals , Dogs , Humans , Vocal Cords/physiology , Phonation/physiology , Glottis/physiology , Laryngeal Mucosa
13.
Sci Rep ; 13(1): 10705, 2023 07 03.
Article in English | MEDLINE | ID: mdl-37400470

ABSTRACT

In laryngeal research, studying the vertical vocal fold oscillation component is often disregarded. However, vocal fold oscillation by its nature is a three-dimensional process. In the past, we have developed an in-vivo experimental protocol to reconstruct the full, three-dimensional vocal fold vibration. The goal of this study is to validate this 3D reconstruction method. We present an in-vivo canine hemilarynx setup using high-speed video recording and a right-angle prism for 3D reconstruction of vocal fold medial surface vibrations. The 3D surface is reconstructed from the split image provided by the prism. For validation, reconstruction error was calculated for objects located at a distance of up to 15 mm away from the prism. The influence of camera angle, changing calibrated volume, and calibration errors were determined. Overall average 3D reconstruction error is low and does not exceed 0.12 mm at 5 mm distance from the prism. Influence of a moderate (5°) and large (10°) deviation in camera angle led to a slight increase in error to 0.16 mm and 0.17 mm, respectively. This procedure is robust towards changes in calibration volume and small calibration errors. This makes this 3D reconstruction approach a useful tool for the reconstruction of accessible and moving tissue surfaces.


Subject(s)
Larynx , Vocal Cords , Animals , Dogs , Imaging, Three-Dimensional/methods , Video Recording/methods , Vibration
15.
Otolaryngol Head Neck Surg ; 169(2): 317-324, 2023 08.
Article in English | MEDLINE | ID: mdl-36939459

ABSTRACT

OBJECTIVE: Partial epiglottidectomy has a role in improving dysphagia due to epiglottic obstruction. This study evaluates objective parameters of swallow function in patients who underwent partial epiglottidectomy. STUDY DESIGN: Retrospective study design. SETTING: Tertiary Care University Academic Medical Center. METHODS: A review was performed of patients who underwent CO2 laser partial epiglottidectomy for the treatment of dysphagia at a single tertiary care academic center over a 4-year period. Objective swallowing parameters were evaluated from pre- and postoperative modified barium swallow studies using SwallowTail Advanced Measurement software using blinded reviewers. The postswallow pharyngeal residue (bolus clearance ratio or BCR), spatiotemporal swallowing variables (oropharyngeal [OPT], hypopharyngeal [HPT], and total pharyngeal transit times [TPT]), and airway protection (Penetration-Aspiration Scale [PAS]) were analyzed. Student paired t test was used to determine significant changes in outcome parameters pre- and postsurgery. RESULTS: Forty-three patients (age range 45-92 years, median 70) met the inclusion criteria. A majority (69.8%) had a history of external beam radiation therapy for head and neck cancer. BCR decreased significantly from a mean of 31.7% presurgery to 24.2% (p = .01) postsurgery. OPT, HPT, and TPT did not differ significantly postsurgery. The mean Eating Assessment Tool-10 score improved from 25.1 to 20.2 after treatment (p = .03). PAS score improved by 15.4% and remained stable at 66.2% after surgery. CONCLUSION: Partial epiglottidectomy improves pharyngeal bolus clearance in properly selected patients with dysphagia due to epiglottic obstruction. Patients demonstrated stable swallow function with the benefit of reduced postswallow residue following surgical intervention.


Subject(s)
Deglutition Disorders , Head and Neck Neoplasms , Humans , Middle Aged , Aged , Aged, 80 and over , Deglutition Disorders/etiology , Deglutition Disorders/surgery , Deglutition , Retrospective Studies , Epiglottis/surgery , Fluoroscopy
17.
Laryngoscope ; 133(2): 357-365, 2023 02.
Article in English | MEDLINE | ID: mdl-35633189

ABSTRACT

INTRODUCTION: Although phonatory glottal posture and airflow pulse shape affect voice quality, studies to date have been limited by visualization of vocal fold (VF) vibration from a superior view. We performed a 3D reconstruction of VF vibratory motion during phonation from a medial view and assessed the glottal volume waveform and resulting acoustics as a function of neuromuscular stimulation. STUDY DESIGN: In vivo canine hemilarynx phonation. METHODS: Across 121 unique combinations of the superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) stimulation, the hemilarynx was excited to the oscillation with airflow. VF medial surface reference points were tracked on high-speed video, mapped into 3D space, and surface shape was restored using cubic spline interpolation. Glottal surface shape, reconstruction-based parameters, and glottal volume waveform were calculated. Fundamental frequency (F0), cepstral peak prominence (CPP), and harmonic amplitude (H1-H2) were measured from high-quality audio samples. RESULTS: The glottis was convergent during opening and divergent during closing. Neuromuscular activation changed phonatory glottal shape and reduced glottal volume. Significant reduction in glottal volume and closing quotient were present with SLN stimulation. RLN stimulation significantly increased F0 and CPP and decreased H1-H2 (constricted glottis), while SLN effects were similar and synergistic with concurrent RLN stimulation. CONCLUSION: 3D reconstruction of in vivo medial surface vibration revealed effects of laryngeal nerve stimulation on glottal vibratory pattern and acoustic correlates of voice quality. SLN activation resulted in significantly quicker glottal closure per cycle, decreased glottal volume, and higher-pitched, less breathy, and less noisy voice. RLN had a similar effect on acoustic measures. LEVEL OF EVIDENCE: NA, Basic Science Laryngoscope, 133:357-365, 2023.


Subject(s)
Glottis , Imaging, Three-Dimensional , Animals , Dogs , Glottis/physiology , Vocal Cords/physiology , Phonation/physiology , Voice Quality , Vibration
18.
Ear Nose Throat J ; 102(8): NP410-NP412, 2023 Aug.
Article in English | MEDLINE | ID: mdl-34030512

ABSTRACT

Tracheal perforation is an extremely rare and potentially dangerous complication of a partial thyroidectomy. The current case represents a unique presentation of delayed tracheal perforation following an uncomplicated thyroid isthmusectomy for tissue diagnosis of an aggressive appearing thyroid mass in the setting of high-dose steroid administration and recent intubation and self-extubation. While conservative management of tracheal perforation can sometimes be appropriate, our patient was successfully managed via primary closure and infrahyoid muscle transposition flap to cover a 5 mm right lateral tracheal wall defect. We recommend caution be exercised following thyroid surgery in the setting of intubation and high-dose steroids.


Subject(s)
Thyroidectomy , Tracheal Diseases , Humans , Thyroidectomy/adverse effects , Tracheal Diseases/etiology , Trachea/surgery , Thyroid Gland , Surgical Flaps
19.
Laryngoscope ; 133(7): 1690-1697, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36129162

ABSTRACT

OBJECTIVES: Surgical manipulations to treat glottic insufficiency aim to restore the physiologic pre-phonatory glottal shape. However, the physiologic pre-phonatory glottal shape as a function of interactions between all intrinsic laryngeal muscles (ILMs) has not been described. Vocal fold posture and medial surface shape were investigated across concurrent activation and interactions of thyroarytenoid (TA), cricothyroid (CT), and lateral cricoarytenoid/interarytenoid (LCA/IA) muscles. STUDY DESIGN: In vivo canine hemilarynx model. METHODS: The ILMs were stimulated across combinations of four graded levels each from low-to-high activation. A total of 64 distinct medial surface postures (4 TA × 4 CT × 4 LCA/IA levels) were captured using high-speed video. Using a custom 3D interpolation algorithm, the medial surface shape was reconstructed. RESULTS: Combined activation of ILMs yielded a range of unique pre-phonatory postures. Both LCA/IA and TA activation adducted the vocal fold but with greater contribution from TA. The transition from a convergent to a rectangular glottal shape was primarily mediated by TA muscle activation but LCA/IA and TA together resulted in a smooth rectangular glottis compared to TA alone, which caused rectangular glottis with inferomedial bulging. CT activation resulted in a lengthened but slightly abducted glottis. CONCLUSIONS: TA was primarily responsible for the rectangular shape of the adducted glottis with synergistic contribution from the LCA/IA. CT contributed minimally to vocal fold medial shape but elongated the glottis. These findings further refine laryngeal posture goals in surgical correction of glottic insufficiency. LEVEL OF EVIDENCE: NA, Basic science Laryngoscope, 133:1690-1697, 2023.


Subject(s)
Glottis , Laryngeal Muscles , Animals , Dogs , Laryngeal Muscles/physiology , Glottis/physiology , Phonation/physiology , Vocal Cords/physiology , Posture , Atrophy
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