ABSTRACT Background and Aims Infectious epiglottitis is inflammation of epiglottis and surrounding structures and may be life‐threatening without treatment. Air pollution is a critical risk factor for human health. This study aims to explore the correlation between infectious epiglottitis and air pollutants. Methods We collected the daily infectious epiglottitis cases in our hospital and the daily meteorological data, including average temperature, relative humidity, and the daily concentrations of air pollutants of Shanghai, China, from January, 2015 to December, 2019. Air pollutants include particulate matter (PM2.5 and PM10), sulfur dioxide (SO2) and nitrogen dioxide (NO2). Generalized additive Poisson regression models were applied to assess the association between the corresponding pollutants and hospital visits for infectious epiglottitis. Results A total of 3280 infectious epiglottitis cases were identified with 1.80 hospital visits per day for all subjects. The mean daily concentrations of PM2.5, PM10, SO2, and NO2 were 39.7 μg/m3, 53.9 μg/m3,11.0 μg/m3, and 40.5 μg/m3, respectively. Spearman correlation analyses indicated a moderate to strong and positive correlation among air pollutants. There was a linear and increasing association between the daily concentration of PM2.5 and hospital visits (p < 0.01). The significant estimate was found in PM2.5 for 1‐day lag (RR = 1.041, 95% CI 1.003, 1.079). No significant association was observed among all lag days for other pollutants. Conclusion Particulate matter 2.5, SO2, and NO2 were significantly associated with infectious epiglottitis incidence in Shanghai. The estimated hospital visits were increased by 4.1% for a 10‐μg/m3 increase in PM2.5 for 1‐day lag.

OBJECTIVE:Vocal fold leukoplakia is commonly managed with outpatient potassium titanyl phosphate (KTP) laser therapy; however, limited data exist on the impact of different pathological grades on long-term efficacy. This study retrospectively analyzed the treatment outcomes, identified prognostic factors, and provided insights to improve disease characterization and clinical management. STUDY DESIGN:Retrospective study (2017-2024). METHODS:Ninety two patients with vocal fold leukoplakia treated in Fudan Eye and ENT hospital (FD-EENT) were included. The mean follow-up period after the last treatment was 20.53 ± 17.32 months. Disease control was assessed by lesion regression using ImageJ analysis. Acoustic outcomes were evaluated using the Voice Handicap Index-30 (VHI-30), GRBAS scale, and other acoustic parameters. RESULTS:Patients underwent a mean of 1.6 treatment sessions. Following the last treatment, the lesion regression rates were 90.1% for no dysplasia, 81.75% for mild dysplasia, and 86.83% for moderate dysplasia, compared to 51.0% for severe dysplasia and 32.9% for carcinoma in situ (CIS). Patients with pathological grades of severe dysplasia and CIS showed significantly poorer treatment outcomes than those with milder dysplasia (***p = 0.0001). CONCLUSION:Outpatient KTP laser effectively controls disease progression in vocal fold leukoplakia, with efficacy linked to the degree of dysplasia. KTP laser is an effective treatment for milder pathological dysplasia, but its efficacy diminishes in more severe stages. The treatment should be carefully considered for patients with severe dysplasia and CIS, with close follow-up, and biopsy should be performed to monitor malignant transformation and prevent delayed treatment. LEVEL OF EVIDENCE: 4:

Objectives This study aims to develop a sulcus vocalis model in the excised canine larynx and to investigate the validity of the model. Methods Type II sulcus vocalis was created by continuous intradermal suture in six excised canine larynges. We investigated the validity of the model based on phonatory (aerodynamic and acoustic) measures, laryngeal videostroboscopy (LVS), and histological examination. The aeroacoustic parameters included phonation threshold pressure (PTP), fundamental frequency ( F o ), jitter %, shimmer %, and harmonics‐to‐noise ratio (HNR). Results In all the experimental specimens, there were significant increases in the PTP ([6.61 ± 1.66] cm H 2 O, p < 0.01), the F o ([106.48 ± 49.59] Hz, p = 0.003), the jitter ([0.76 ± 0.42]%, p = 0.007), the shimmer ([6.87 ± 2.99%, p = 0.002]), while the HNR decreased ([5.71 ± 4.68] dB, p = 0.031), compared to that of the untreated canine larynges. The estabilished model simulated the histology with type Ⅱ sulcus. Conclusions Type Ⅱ sulcus vocalis was successfully created in excised canine larynx. The aeroacoustic and LVS analysis of this model resembled the characteristics of patients with sulcus vocalis. The model could be helpful to elucidate the pathology of the phonation, and evaluate and compare the treatments for sulcus vocalis.

Objective: Dysphonia is very common worldwide and aerosol drug inhalation is an important treatment for patients with dysphonia. This study aimed to explore the effects of vocal fold (VF) lesions on the particle deposition pattern using computational modeling. Methods: A realistic mouth-throat (MT) model of a healthy adult was constructed based on computed tomography images. Small and large vocal fold lesions were incorporated in the original model. A steady inhalation flowrate of 15 and 30 liter per minute (LPM) was used as the velocity inlet and monodisperse particles with diameters of 5 to 10 mu m were simulated. Results: Particles of larger size are more likely to be deposited in MT models, most of them distributed in oral cavity, oropharynx and supraglottis. The ideal sizes at 30 LPM ranged over 7-10 mu m for healthy VFs and 6-8 mu m for VF lesions. The best sizes at 15 LPM ranged over 6-8 mu m for healthy VFs and 8-9 mu m for VF lesions. Conclusion: Based on this study, VF lesions influence the deposition pattern in the glottis obviously. The ideal sizes differ at the flow rates of 15 and 30 LPM. (c) 2023 Japanese Society of Otorhinolaryngology-Head and Neck Surgery, Inc. Published by Elsevier B.V. All rights reserved.

BACKGROUND:The efficacy of inhalation therapy depends on the drug deposition in the human respiratory tract. This study investigates the effects of vocal fold adduction on the particle deposition in the glottis. METHODS:A realistic mouth-throat (MT) geometry was built based on CT images of a healthy adult (MT-A). Mild (MT-B) and great (MT-C) vocal fold (VF) adduction were incorporated in the original model. Monodisperse particles range in size from 3 to 12 μm were simulated at inspiration flow rates of 15, 30 and 45 L per minute (LPM). The regional deposition of drug aerosols was performed in 3D-printed models and quantified using high-performance liquid chromatography. RESULTS:Both the numerical analysis and in vitro experiments show that most particles are deposited in the mouth, pharynx and supraglottis, while few are deposited in the glottis and subglottis. For most cases in MT-A, the particle quantity in glottis is lower than 0.02 N/mm2 at 15 and 30 LPM while they increase dramatically at 45 LPM. It peaked at 0.347 N/mm2 for 5-μm particles at 45 LPM in MT-B and 2.324 N/mm2 for 6-μm particles at 30 LPM in MT-C. The lowest drug mass faction in the glottis in vitro were found at 15 LPM for MT-A and MT-C, and at 30 LPM for MT-B, whereas it peaked at 45 LPM for all MT models, 0.71% in MT-A, 1.16% in MT-B, and 2.53% in MT-C, respectively. CONCLUSION:Based on the results of this study, larger particles are more likely to be deposited in the oral cavity, oropharynx, and supraglottis than in the glottis. However, particle deposition in the glottis generally increases with VF adduction and greater inspiratory flow rates.

Abstract Objectives The compound betamethasone is widely used to prevent scarring in dermatology. This study aims to explore the effects of compound betamethasone on vocal fold (VF) wound healing. Study design Prospective animal study in rabbits. Methods Eighteen rabbits underwent bilateral VF stripping and three rabbits served as controls. 0.1 mL of compound betamethasone (1 mL: betamethasone sodium phosphate 5 mg and betamethasone dipropionate 2 mg) was injected into the right VF of each rabbit, and 0.1 mL 0.9% saline was injected into the contralateral VF. Endoscopy was performed for morphologic observation. Six larynges were harvested for histological analysis at 3 days, 7 days, and 1 month. The VFs were stained with hematoxylin and eosin (H&E), Alcian blue, and Masson' trichrome staining. Results In morphological analysis, there was no visible difference between betamethasone‐treated and saline‐treated VFs at 3 and 7 days. After 1 month, more VF scars appeared on the saline‐treated VFs than the VFs treated with betamethasone. Inflammatory cell number showed significant difference between both VFs at 3 days (p = .037) and 7 days (p = .045). No significant different was found in epithelial thickness at 1 month between the betamethasone and saline groups. The collagen in the saline‐treated VFs was significantly denser than that of the betamethasone‐treated group (p = .037). There was also a significant increase in the level of hyaluronic acid (HA) in betamethasone‐injected VFs in comparison to the saline‐injected VFs (p = .006). Conclusions Based on this study, compound betamethasone can improve VF healing. Our findings suggest that VF injection with compound betamethasone helps to minimize scarring by increasing HA level and decreasing collagen density.

Introduction: Foreign bodies (FBs) in the external auditory canal (EAC) are common in pediatric otorhinolaryngology. Although clinicians have tried many methods and tools to treat these patients, removing the spherical FBs embedded deep in EAC is still a challenge. Occasionally successful removal of such FBs requires local or general anesthesia. Case Presentation: Here, we developed a simple and novel 3-dimensional (3D) printing tool to successfully treat a child suffering from a spherical FB in EAC. The child received no further treatment, and no complications developed afterward. Conclusions: It is challenging to remove spherical FBs in EAC. We developed a tiny, safe, and cheap tool to treat a child with such a FB in EAC. The clinical outcome was satisfactory.

Background Anterior glottoplasty is a commonly used treatment for voice feminization. But it remains in dispute over whether to suture of the ligament as part of the procedure. Objectives This study aimed to explore the effect of inclusion of the vocal lamina propia. Material and methods Anterior webs were created in 8 excised canine larynges by sutures placed at 10%, 20%, and 30% of the vocal fold length, respectively. The suture depth was divided into two groups: epithelium layer (Shallow Suture, SS group) and deep layers of vocal fold lamina propia (Deep Suture, DS group). Results For anterior webs between 0% and 30%, the frequency elevation ranged from 3% to 151% of the pre-web fundamental frequency (fo) in SS group and from 13% to 222% in DS group. No significance was found between two groups at three different sutures (p = .486 for suture at 10% of vocal fold length, 0.686 for 20%, 0.886 for 30%, respectively). Conclusions and significance The frequency in excised canine larynx increased continuously as the anterior glottic webs ranged from 0% to 30%. The inclusion of the vocal fold lamina propia does not affect the frequency elevation.

Objective: Acute pharyngitis is common worldwide. Meteorological changes contribute to respiratory infections. This study aims to explore the correlation between acute pharyngitis and meteorological parameters. Methods: We collected the monthly acute pharyngitis cases in our hospital and the meteorological data, including temperature, relative humidity, and air quality index (AQI) of Shanghai, China, from January, 2015, to December, 2017. Pearson correlation and multivariable regression analysis were used to explore the association between meteorological parameters and the monthly hospital visits. Results: A total of 8287 patients were included in this study, and the monthly number of hospital visits was 230.2 ± 39.0. The best air quality index was 46.4 and the worst was 113.2. Temperature ranged from 5.2°C to 32.0°C, and relative humidity ranged from 59.4% to 83.1%. The monthly hospital visits of acute pharyngitis were negatively correlated with temperature (r = −.558, 95% CI −.746, −.274) and relative humidity (r = −.480, 95% CI −.695, −.137). A decrease of 1°C could cause an increase in hospital visits by 1.9. No significant correlation was found were found between acute pharyngitis cases and AQI (P = .051, 95% CI −.005, .590). Multivariable linear regression analysis showed the temperature was the independent risk factor of acute pharyngitis (coefficient = −1.906, P = .022). Conclusion: Low temperature might cause an increased incidence of acute pharyngitis.

ObjectivesStraw phonation has been investigated for its vocal warm‐up effects on healthy populations and therapeutic effects on voice patients. The purpose of this article was to determine whether it is beneficial for vocal fatigue.Study DesignProspective cohort studyMethodsTwenty‐five healthy participants were recruited into 1‐hour vocal loading tasks followed by 10‐minute vocal rest or straw phonation on 2 different days. Various parameters including phonation threshold pressure (PTP), mean airflow, closed quotient (CQ), current speaking effort level (EFFT), and laryngeal discomfort (DISC) were acquired at baseline, after vocal load, and after the intervention.ResultsIncreased PTP, EFFT, and DISC were observed after vocal load. Decreased PTP, EFFT, and DISC were then acquired after both vocal rest or straw phonation. More significant improvements were obtained in straw phonation when compared with vocal rest. Additionally, significantly increased mean flow and decreased CQ were obtained after straw phonation when compared to vocal rest.ConclusionsStraw phonation has the potential to adjust aerodynamics within the vocal tract leading to improved vocal efficiency, optimized vibration mode, and attenuated vocal fatigue. This study provided a promising treatment for vocal fatigue that could have wide clinical relevance to voice users with high voice demands.Level of Evidence4 Laryngoscope, 130:E674–E679, 2020

Background: Photobiomodulation (PBM) is increasingly used in dermatology and dentistry due to its benefit of promoting wound healing and relieving pain; however, there is no corresponding research report on the application of PBM to vocal fold wound healing. Objective: To assess the potential wound-healing effects of PBM on the vocal folds via in vivo and in vitro experiments. Materials and methods: In in vitro study, vocal fold fibroblasts (VFFs) were irradiated under a diode laser with wavelength of 635 nm at energy density of 8 J/cm2. The Cell Counting Kit-8 (CCK-8) assay was used to study the viability of VFFs, and the gene expressions of COL1A2, COL3A1, IL-6, HAS2, and COX-2 were investigated by real-time polymerase chain reaction (RT-PCR). In in vivo study, 15 rabbits were used. Lamina propria of the left vocal folds of 12 rabbits was unilaterally stripped, and 6 of them were treated with PBM. The remaining three rabbits served as normal controls. After 3 months, all animals were sacrificed to obtain histological results. We used laryngoscope to record images of the healing phase. Results: Irradiation with energy density of 8 J/cm2 resulted in a 2.8% increase in cell proliferation (p < 0.05). However, the difference between the experimental and the control group became larger after 48 and 72 h of subsequent irradiation. RT-PCR results showed that the expression of COL1A2, COL3A1, and HAS2 was higher, and the expression of IL-6 and COX-2 was lower. Histological examination showed that, compared with the injury group, hyaluronic acid (HA) increased significantly, collagen deposition decreased, and the configuration of collagen was more organized after PBM treatment. Conclusions: PBM can inhibit inflammatory reaction and promote the secretion of HA to decrease the deposition of collagen and regenerate vocal fold tissue without scar.

OBJECTIVE:This study aimed to investigate the duration of straw phonation effects using aerodynamic, electroglottographic, and acoustic metrics.METHODS:Twenty-four participants were recruited to perform both a 5-minute and a 10-minute straw phonation exercise. Upon completion of the exercises, phonation threshold pressure (PTP), mean airflow, contact quotient, fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio were measured over a 20-minute time frame. Parameters were measured before the intervention (baseline), immediately after the intervention (m0), 5 minutes (m5), 10 minutes (m10), 15 minutes (m15), and 20 minutes (m20) after the intervention.RESULTS:PTP significantly decreased immediately after 5 minutes of straw phonation and returned to initial state within 5 minutes. PTP remained decreased over 5 minutes after 10 minutes of straw phonation. Mean airflow increased immediately after both 5 minutes and 10 minutes of straw phonations and remained improved for 20 minutes. No significant changes were obtained for contact quotient and acoustic parameters over the intervention period.CONCLUSIONS:The results extended our knowledge of proper clinical application of straw phonation regarding the duration of exercise. This study confirmed that 10 minutes of straw phonation lead to optimal and relatively continuous effects in PTP and mean airflow. Although straw phonation did show lingering effects in aerodynamics, repeated practices were recommended to obtain optimum and therapeutic effects.

Low-level laser therapy (LLLT) has been promoted for its beneficial effects on tissue healing and pain relief for skin and oral applications. However, there is no corresponding literature reporting on vocal fold wound healing. Our purpose was to assess the potential wound-healing effects of LLLT on primary human vocal fold epithelial cells (VFECs). In this study, normal vocal fold tissue was obtained from a 58-year-old male patient who was diagnosed with postcricoid carcinoma without involvement of the vocal folds and underwent total laryngectomy. Primary VFECs were then cultured. Cells were irradiated at a wavelength of 635 nm with fluences of 1, 4, 8, 12, 16, and 20 J/cm2 (50 mW/cm2), which correspond to irradiation times of 20, 80, 160, 240, 320, and 400 s, respectively. Cell viability of VFECs in response to varying doses of LLLT was investigated by the Cell Counting Kit-8 (CCK-8) method. The most effective irradiation dose was selected to evaluate the cell migration capacity by using the scratch wound-healing assay. Real-time polymerase chain reaction (RT-PCR) was used to detect the gene expression of TGF-β1, TGF-β3, EGF, IL-6, and IL-10. Irradiation with doses of 8 J/cm2 resulted in 4% increases in cell proliferation differing significantly from the control group (p < 0.05). With subsequent doses at 48 and 72 h after irradiation, the differences between the experimental and the control groups became greater, up to 9.8% (p < 0.001) and 19.5% (p < 0.001), respectively. It also increased cell migration and the expression of some genes, such as EGF, TGF-β1, TGF-β3, and IL-10, involved in the tissue healing process. This study concludes that LLLT at the preset parameters was capable of stimulating the proliferation and migration of human vocal fold epithelial cells in culture as well as increase the expression of some genes involved in tissue healing process. Additionally, successive laser treatments at 24 h intervals have an additive beneficial effect on the healing of injured tissues.

Objectives: The aim of this study was to quantify the effects of traditional and physiological warmup exercises and to determine the optimal duration of these methods using acoustic and aerodynamic metrics. Methods: Twenty-six subjects were recruited to participate in both straw phonation exercises (physiological vocal warm-up) and traditional singing exercises (traditional vocal warm-up) for 20 minutes each, 24 hours apart. Phonation threshold pressure (PTP), fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio were measured before the intervention (m0), as well as after 5 minutes (m5), 10 minutes (m10), 15 minutes (m15), and 20 minutes (m20) of intervention. Results: PTP decreased significantly after straw phonation and reached a minimum value at 10 minutes (P< 0.001) and remained stable in traditional singing exercises. There were significant differences in fundamental frequency and shimmer from m0 to m15 and m20 in the traditional singing group (P = 0.001, P = 0.001, P= 0.001, and P = 0.002, respectively). No significant changes in acoustic parameters were observed after straw phonation. Conclusions: Both straw phonation exercises and traditional singing exercises are effective for voice warm-up. Straw phonation improves the subjects' fatigue resistance and vocal economy, resulting in a reduced PTP, whereas traditional singing exercises focus on technical singing skills, leading to an improvement of acoustic variables.

OBJECTIVES:This study aimed to quantify the effects of vocal loading and vocal rest using aerodynamic, acoustic, and self-rating measurements. METHODS:Ten participants were recruited to perform vocal loading tasks lasting 60 minutes, followed by 30 minutes of vocal rest. Objective parameters (phonation threshold pressure, fundamental frequency, jitter, shimmer, and noise-to-harmonics ratio) and subjective parameters (current speaking effort level and laryngeal discomfort) were taken at different time intervals: before vocal loading (baseline), after 15 minutes (L15), 30 minutes (L30), 45 minutes (L45), and 60 minutes (L60) of vocal loading, as well as after 5 minutes (R5), 10 minutes (R10), 20 minutes (R20), and 30 minutes (R30) of vocal rest. RESULTS:Phonation threshold pressure was found to increase significantly within the first 15 minutes of the vocal loading task (P = 0.032), followed by a relatively gentle increase in the subsequent 45 minutes. Subjective self-ratings increased significantly after 30 minutes of loud reading (P < 0.05). Phonation threshold pressure recovered faster than subjective parameters after the vocal loading activity had finished. Fundamental frequency was found to consistently increase during vocal loading but return to baseline rapidly within 5 minutes of vocal rest. However, no significant changes in jitter, shimmer, and noise-to-harmonics ratio were observed after vocal loading. CONCLUSIONS:Phonation threshold pressure and self-ratings may have the potential to track vocal fatigue and recovery. Furthermore, a dynamic monitor of vocal fatigue was presented, which may further provide a guide for appropriate voice use.

To establish a novel and effective reflux model with a modified nasogastric aspiration tube and to investigate the association between different types of nasogastric aspiration tubes and reflux laryngitis, we conducted this study.

Objective: To evaluate a cost-effective modified rigid laryngoscopy setup with a portable light source and high-resolution commercially available digital camera for use in smaller otolaryngology and family practice clinics. Methods: The modified setup was used to obtain images of the larynx using both a traditional light source and a portable light source. Varying shutter speeds and ISOs were evaluated, and the optimal settings were determined for the modified setup. Results: Picture quality was adequate, and the portable light source was bright enough. ISO from 640 to 1600 with shutter speeds ranging from 1/60 to 1/160 are ideal under the normal light source, while it is better to set the ISO between 4000 and 10 000 with shutter speeds from 1/60 to 1/100 under the portable light source. Picture quality was adequate with a resolution of 2768 pixels × 1848 pixels with 350 dpi × 350 dpi. Conclusions: Results show that the modified setup obtains images of adequate quality for use in the clinic. Additionally, since the larynx requires the most illumination for endoscopic imaging, a similar setup would work for imaging the ear and nose. This setup may make laryngoscopic exams more accessible to patients at smaller laryngoscopy clinics or family practice providers.

The main objective of the study is to model asymmetry within anterior glottic webs in excised larynges using sutures and apply aerodynamic and acoustic analyses. Anterior glottic webs (AGW) were modeled in eight excised larynges using sutures secured at the level of the glottis to mimic the scar tissue of the web. Each of the eight larynges were tested under three different pressure increments for each of the three models of AGW: symmetric, vertically asymmetric, and laterally asymmetric. Phonation threshold pressure (PTP) and flow (PTF) differed significantly across AGW conditions (p = 0.006 and p = 0.005, respectively). Additionally, vocal efficiency was significantly different among conditions (p = 0.005) as well as significantly lower in the asymmetric groups (p = 0.015 and p = 0.007). Perturbation measures were not significantly different across conditions. Correlation dimension (D2) was significantly different at PTP, 1.25 × PTP, and 1.5 × PTP (p = 0.003, p = 0.010, and p < 0.001, respectively) as well as significantly higher in the asymmetric groups at each pressure increment. The increased PTP, PTF, and D2 values as well as decreased vocal efficiency among the asymmetric conditions indicates a significant decrease in vocal function, and thus represents that asymmetries could be a contributing factor to the pathological symptoms associated with glottic webs.

Objectives. This study aims to build an excised anterior glottic web (AGW) model and study the basic voice-related mechanisms of the AGW through investigating the acoustic, aerodynamic, and vibratory properties.Study Design and Methods. Overall, four conditions were tested for each of the eight canine larynges used. At baseline, 10%, 20%, and 33% occlusion (as determined by the placement of the suture), acoustic, aerodynamic, and high-speed video data were collected while each larynx was phonated in a soundproof booth.Results. The phonation threshold pressure (PTP) and the phonation threshold flow significantly increased as percent occlusion increased (P < 0.001). There were significant increases in jitter % and shimmer % from baseline group to AGW model groups at PTP, 1.25 PTP, and 1.5 PTP (P = 0.039, P < 0.001, P < 0.001, P < 0.001, P < 0.001, and P = 0.001, respectively). The fundamental frequency significantly increased as percent occlusion increased at all given pressures (P < 0.001). Correlation dimension (D2) was significantly higher in the AGW model groups than in the baseline group at PTP, 1.25 PTP, and 1.5 PTP (P = 0.002, P < 0.001, P = 0.01, respectively). High-speed videos revealed that, the left phase shift in the AGW model groups compared with the baseline at 1.25 PTP was significant (P = 0.027) and right phase shift at 1.5 PTP (P < 0.001).Conclusions. We presented an anatomically similar model of a type 1 AGW and confirmed its validity through aerodynamic, acoustic, and high-speed video analysis in our study. We observed and investigated the glottic web movement, which may be a new explanation for the pathologic voice-related mechanism of AGW.