INTRODUÇÃO: As queixas vocais e de deglutição podem ser apresentadas após o tratamento cirúrgico da doença de tireóide em pacientes com ou sem a mobilidade laríngea preservada. O objetivo do presente estudo foi avaliar e comparar a voz e a deglutição de pacientes com e sem mobilidade laríngea alterada após a tireoidectomia. MÉTODOS: Estudo prospectivo no qual foram avaliados pacientes com doença de tireóide divididos em dois grupos: GA, com mobilidade laríngea alterada após a tireoidectomia e GB, preservada. O protocolo de avaliação vocal perceptivo-auditiva e acústica e nasofibroscopia da deglutição foi aplicado no pré, pós-operatório recente e tardio. Ambos apresentaram percentual maior de mulheres, da faixa etária entre 46 a 65 anos e de tireoidectomia total. O número reduzido de tabagistas e da indicação de esvaziamento cervical também foi comum aos dois grupos. O carcinoma papilífero foi mais freqüente no GA e o bócio, no GB; e o volume do tecido ressecado foi menor no GA em relação ao GB. RESULTADOS: A avaliação da deglutição revelou que no GA, não houve alteração no pré-operatório (PRE). No pósoperatório recente (POR) foi observada em 87% e no pós-operatório tardio (POT), em 67%. Houve diferença estatística entre os períodos PRE e POR e PRE e POT (p<0,001). A penetração e aspiração com líquido foram identificadas em 33% da amostra no POR (p=0,014). A estase de alimento ocorreu em 87% no POR e 60% no POT(p<0,001). No GB, somente os resultados entre PRE e POR tiveram significância estatística para deglutição, com aumento de 44% no número de indivíduos com disfagia, apresentando estase e escape prematuro do alimento. Os resultados de voz indicaram que a disfonia em grau discreto caracterizada pela rugosidade esteve presente em 67% da amostra do GA no PRE. Houve diferença significativa entre PRE e POR, no grau geral, tensão, instabilidade, pitch, loudness e foco ressonantal. Entre PRE e POT, a significância ocorreu apenas no pitch e loudness. Os dados acústicos não apresentaram diferença relevante no GA. No GB, 87% foi classificado como disfônico no PRE, com rugosidade (85%) discreta (64%) e ressonância faringolaríngea (67%) como as características mais notadas. A comparação entre PRE e POR revelou piora com diferença significante no grau geral, tensão, pitch e loudness. Entre PRE e POT, houve diferença apenas no pitch e loudness. CONCLUSÕES: Pacientes com doença de tireóide apresentam disfonia mesmo antes da cirurgia. Após a tireoidectomia, apresentam disfonia e disfagia, mais evidentes no pós-operatório recente e mais graves nos indivíduos com mobilidade laríngea alterada. As disfunções estão associadas a fatores supraglóticos e faríngeos e não somente a mobilidade de pregas vocais e podem ocorrer devido a intubação orotraqueal, manipulação da musculatura extrínseca e danos do nervo laríngeo. / INTRODUCTION: The vocal and deglutition complaints can be presented after surgical treatment of thyroid disease in patients with or without preserved laryngeal mobility. The objective of this study was to evaluate and to compare the voice and swallowing function of patients with and without laryngeal mobility after thyroidectomy. METHODS: This prospective study evaluated patients with thyroid disease divided in two groups: GA with laryngeal mobility modified after surgery and GB, preserved. The perceptual and acoustical analysis and fiberoptic endoscope of swallowing evaluation protocol were applied at preoperatory, recent and late post operatory. Both groups had presented bigger percentage of women, with age between 46 and 65 years, and total thyroidectomy. Reduced numbers of smokers and indication of neck dissection was common to the two groups. Papillary carcinoma was more frequent in the GA, and the benign tumor in the GB; and resected tissue volume was smaller in the GA in relation to GB. RESULTS: The evaluation of the deglutition indicated that the GA did not have alteration at preoperatory (PRE). At recent postoperative (POR) it was observed in 87% and at late period (POT), in 67%. There was statistical difference between PRE and POR, and PRE and POT (p< 0,001). Penetration and aspiration with liquid had been identified in 33% of the sample at POR (p=0,014). Residue of food occurred in 87% at POR and 60% at POT (p< 0,001). In the GB, the results between PRE and POR had significance only for deglutition, with increase of 44% in the number of individuals with dysphagia, presenting residue and premature escape of the food. Voice results had indicated light degree dysphonia characterized by the roughness in 67% of the sample of the GA at PRE. There was significant difference between PRE and POR, in the global grade, strain, instability, pitch, loudness and resonance focus. Between PRE and POT, the significance it occurred only in pitch and loudness. The acoustic data had not presented statistical difference in the GA. In GB, 87% was classified as dysphonic at PRE, with light (64%) roughness (85%) and pharyngolaryngeal resonance (67%) as the more observed characteristics. The comparison between PRE and POR showed worsening with significant difference in the global grade, strain, pitch and loudness. Between PRE and POT, it had difference only in pitch and loudness. CONCLUSIONS: Patients with thyroid disease present dysphonia before the surgery. After thyroidectomy, presents dysphonia and dysphagia, evidenced at POR and more severe in the individuals without laryngeal mobility. These dysfunctions are associated to pharyngeal and laryngeal factors and occur due to orotracheal intubation, manipulation of the extrinsic muscle and damage of the laryngeal nerve.

Ensaios realizados em papel para investigação e conhecimento de tipologias de forma geradas a partir da bidimensionalidade, construídas por princípios de dobragem, corte e entrelaçamento. Realizado por método experimental criativo, os ensaios foram inspirados, reproduzidos e gerados a partir da observação de florescência e crescimento de plantas, de texturas e princípios têxteis, de cordas e linhas, elementos de padronagem, geometria e desenhos livres, desenvolvidos manualmente, sendo os cortes executados em máquina de corte a laser. A superfície ora é modificada, caracterizando um plano diferente, ora constitui uma unidade modular, desenhada pelo corte, que multiplicada e combinada, deriva outros planos ou formas bi e tridimensionais. A interferência no plano modifica sua visualidade, textura, acústica, e funcionalidades, como flexibilidade, permeabilidade, colapsibilidade, seu comportamento, assim como a percepção e apreensão da forma pelos sentidos. O objetivo da pesquisa é ordenar classes de tipologias formais básicas para compreender leis elementares de construção e comportamento da forma material, cujos princípios geram outras formas mais complexas. / Experiments made on paper for research and knowledge of form typologies generated from bidimensionality, created by folding, cutting and interlacement principles. Developed by creative experimental method, the experiments were inspired, reproduced and generated from the observation of plants inflorescence and growth, textures and textiles principles, of ropes and threads, patterning elements, geometry and free drawings, manually produced, being cut on a laser cutting machine. The surface is either modified, featuring a different plan, or constituting a modular unit designed by the shape of the cut, which being multiplied and combined, derives other plans or bi and tridimensional forms. The interference in any plan modifies its visuality, texture, acoustics, and features such as flexibility, permeability, collapsibility, its behavior, as well as the perception and apprehension of the form by the senses. The objective of the research is to order classes of basic typologies of form to understand basic laws of construction and behavior of the material form, which principles generate more complex forms.

Orientador: Agrício Nubiato Crespo / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-17T15:39:14Z (GMT). No. of bitstreams: 1 Carvalho_EduardoGeorgeBaptistade_D.pdf: 1487097 bytes, checksum: 8b21a6026c0fd35ff39cc175609d11d7 (MD5) Previous issue date: 2011 / Resumo: A correção de sulcos e cicatrizes de pregas vocais permanece como grande desafio à fonocirurgia. Substâncias que promovam a reestruturação da lâmina própria parecem ser a melhor opção. Esta pesquisa avaliou a influência do fator de crescimento de fibroblastos na integração tecidual de enxerto de fragmento de fáscia superficial na lâmina própria de prega vocal de coelhos associado à injeção de FGF, quanto às alterações histológicas induzidas como reação inflamatória aguda e crônica, fibrose desencadeada pelo procedimento e presença de neovascularização. Doze coelhos adultos foram submetidos ao enxerto de fragmento de 0,1 X 0,1 cm de fáscia cervical superficial na lâmina própria de ambas as pregas vocais. Na prega vocal direita foi injetado fator de crescimento de fibroblastos. Após um e doze meses, os animais foram sacrificados e suas pregas vocais submetidas a estudo histológico. O fator de crescimento de fibroblastos induziu resposta inflamatória em todos os animais após um mês do experimento inicial. Desencadeou fibrose além da causada pelo procedimento cirúrgico na prega vocal direita em todos os animais após 12 meses do experimento inicial. Fato que demonstra que o fator de crescimento de fibroblastos não representa uma boa opção terapêutica na correção das alterações da lâmina própria de pregas vocais quando associado ao enxerto de fáscia. / Abstract: The correction of sulcus and scars of vocal cords remains as a major challenge to fonosurgery. Substances which promote the restructuring the lamina propria seem to be the best option. This study evaluated the influence of fibroblasts growth factor in integration fragment of fascia grafted in the vocal fold lamina propria of rabbits associated with the injection FGF, regarding the histological alterations , acute and chronic inflammatory reaction, fibrosis, presence of neovascularization and the density of collagen. Twelve adult rabbits were submitted to grafting of fragment of 0.1 X 0.1 cm cervical fascia in the vocal fold lamina propria. Fibroblasts growth factor was injected in the right vocal fold. After a month and 12 months, the animals were sacrificed and their vocal folds submitted to histological study. The fibroblasts growth factor induced acute inflammatory response in all animals after one month of initial experiment. It induced fibrosis in addition to the caused by surgical procedure on the right vocal fold in all animals after 12 months of initial experiment. Fact which demonstrate that the fibroblasts growth factor with fascia grafting is not a good therapeutic option in correction of alterations of the vocal fold lamina propria. / Doutorado / Otorrinolaringologia / Doutor em Ciências Médicas

Corticosteróides injetáveis têm sido usados em fonocirurgia com o intuito de se prevenir fibrose da prega vocal pelos seus efeitos na cicatrização e assegurar uma melhor qualidade vocal. O objetivo deste estudo é avaliar histologicamente os efeitos da infiltração de dexametasona no processo agudo de cicatrização, 3 e 7 dias após uma lesão induzida cirurgicamente na prega vocal de coelhos, através da análise quantitativa da reação inflamatória e da deposição de colágeno. Uma incisão cirúrgica foi realizada nas pregas vocais de 12 coelhos, seguido da injeção de 0,1ml de dexametasona na prega vocal esquerda. A prega vocal direita não recebeu nenhuma injeção e serviu como grupo controle. As laringes foram coletadas 3 e 7 dias após a cirurgia. As pregas vocais foram histologicamente analisadas com hematoxilina-eosina para quantificar a resposta inflamatória e picrossírius-red para quantificar a deposição de colágeno. Quantitativamente, não houve diferença significativa na resposta inflamatória das pregas vocais com corticosteróide em relação ao controle. A deposição de colágeno no grupo com corticóide foi estatisticamente menor em 3 dias e permaneceu menor em 7 dias após a lesão cirúrgica (p=0,002). Esses resultados sugerem que os corticosteróides diminuem a deposição do colágeno no processo agudo da cicatrização / Injectable corticosteroids have been used in phonosurgery to prevent scarring of the vocal fold due to their effects on wound healing, and to assure better voice quality. The aim of this study is to evaluate histologically the effects of dexamethasone infiltration on acute vocal fold wound healing in rabbits 3 and 7 days after surgically-induced injury, by quantification of the inflammatory reaction and collagen deposition. A standardized surgical incision was made in the vocal folds of 12 rabbits, and 0.1 ml dexamethasone (4 mg/ml) was injected into the left vocal fold. The right vocal fold was not injected and served as the control. The larynges were collected 3 and 7 days after surgery. For histological analysis, the vocal folds were stained with hematoxylin-eosin for quantification of the inflammatory response and with picrosirius red for quantification of collagen deposition. There was no quantitative difference in the inflammatory response between vocal folds injected with the corticosteroid and the control folds. However, collagen deposition was significantly lower in the corticosteroid-treated group at 3 and 7 days after the injury (p = 0.002). The present results suggest that dexamethasone reduces collagen deposition during acute vocal fold wound healing

Vários materiais têm sido introduzidos nas pregas vocais na tentativa de solucionar a incompetência glótica, porém poucos são os estudos que avaliam o processo cicatricial decorrente da enxertia destes materiais. O objetivo desta pesquisa foi quantificar o processo inflamatório celular na prega vocal de coelhos submetidos a enxerto unilateral de gordura ou fáscia muscular. Estudamos 24 coelhos, divididos em 2 grupos, nos quais gordura ou fáscia foi enxertada. O grupo controle foi formado pela prega vocal contralateral, a qual foi submetida ao mesmo procedimento, excetuando-se a colocação do enxerto. Metade dos coelhos de cada grupo foi sacrificada após 90 dias, enquanto a outra metade foi sacrificada após 180 dias da cirurgia. A densidade celular inflamatória peri-enxerto foi avaliada em todas as pregas vocais. Houve um aumento do infiltrado inflamatório no grupo submetido à enxertia de gordura, quando comparado ao submetido à enxertia de fáscia. Bem como ao grupo controle, após 90 dias. Quanto aos coelhos sacrificados após 180 dias, não houve diferença entre os grupos entre si e em relação ao grupo controle. Esse estudo sugere que o enxerto de fáscia parece ser mais aceitável que o enxerto de gordura para a prega vocal, uma vez que origina menor reação inflamatória tecidual / Several material have been introduced into the vocal folds in attempt to solve glottic incompetence, however just a few studies are related with the consequent inflammatory process. The aim of this article was to quantify the cellular inflammatory process in rabbit vocal fold, which have undergone unilateral fat or muscular fascia introduction. Twenty-four rabbits were allocated into two groups, in which muscular fascia or fat were implanted. The control group, formed by the contra-lateral vocal fold, underwent the same surgical procedure, except for the grafting. Half the rabbits from each group were sacrificed after 90 days from the surgery, while the other half was sacrificed after 180 days. The inflammatory cellular density around the graft was measured in all vocal folds. There was a higher cellular inflammatory reaction in the group submitted to fat grafting when compared to the group submitted to muscular fascia grafting, and to the control group, after 90 days. As for the rabbits sacrificed after 180 days, there was no significant difference between the implanted groups with each other, and with the control group. This study suggests that muscular fascia graft seems to be more acceptable than fat grafts for the vocal fold, as it produces a lower local inflammatory reaction

No presente trabalho buscou-se compor um quadro geológico-estrutural da Faixa Paraguai meridional e compreender as relações estratigráficas entre os litotipos da Formação Puga e grupos Cuiabá e Corumbá. Foram realizados trabalhos de reconhecimento geológico e perfis geológico-estruturais de detalhe, com análise estrutural e petrográfica, em conjunto com a integração de dados e mapas existentes, análise de imagens de satélite, fotos aéreas e modelos digitais de terreno. A Faixa Paraguai meridional evoluiu como um típico fold-andthrust belt. A evolução geológica do cinturão principia por processos de rifteamento, provavelmente no final do Criogeniano, evoluindo para mar restrito e margem passiva até o final do Ediacarano. A fase rifte é caracterizada pelas formações Puga e Cerradinho. A fase margem passiva está representada pelas formações Bocaina, Tamengo e Guaicurus. Propõe-se que o Grupo Cuiabá na área estudada seja constituído por depósitos marinhos profundos, turbidíticos distais depositados comitantemente aos sedimentos do Grupo Corumbá. O processo colisional responsável pela inversão da bacia com a deformação e metamorfismo associados ocorreu durante o Cambriano, com magmatismo pós-colisional no Cambriano Superior. O estilo estrutural torna-se progressivamente mais complexo de oeste para leste. São observadas até três fases de dobramento coaxiais sobrepostas com eixos subhorizontais de direção N-S. Associam-se a sistemas de falhas de empurrão com deslocamento da capa para oeste. As lineações de estiramento e indicadores cinemáticos observados sugerem que a convergência colisional em direção ao bloco Rio Apa que deu origem à faixa móvel não foi completamente frontal, existindo algum grau de obliquidade, com vetores de convergência em torno de WNWENE. Os micaxistos do Grupo Cuiabá mostram o estilo estrutural mais complexo, com três fases de dobramentos coaxiais e foliações tectônicas mais intensas. Haveria correlação temporal entre S3 gerada nos micaxistos, comumente referidos como Grupo Cuiabá, a leste com a foliação S2 gerada na porção central e a clivagem S1 gerada no limite da área cratônica a oeste, padrão que pode ser explicado pela migração do front deformacional de leste para oeste. É sugestivo que as principais falhas de empurrão coincidam com limites bacinais importantes, onde ocorrem variações de espessura e representatividades das formações basais. No processo de inversão da bacia provavelmente os empurrões reativaram as antigas falhas lístricas principais do estágio rifte. / This work aims to characterize the geological and structural context of the Southern Paraguay Folded Belt, and to understand the stratigraphic relationships between the Puga Formation, Corumbá and Cuiabá groups. Regional geological reconnaissance work and detailed geological-structural field sections were carried out, with petrographic and structural analysis, together with integration of existing data and maps and analysis of satellite images, aerial photos and digital terrain models. The southern Paraguay Belt is a typical fold-andthrust belt. Its geological evolution began with rifting (Puga and Cerradinho formations), probably at the end of Criogenian, and evolved to restricted sea and passive margin (Bocaina, Tamengo and Guaicurus formations) in the late Ediacaran. It is proposed that the Cuiabá Group in the study area consists of distal marine deposits coeval with the Corumbá Group. The collisional process responsible for basin inversion and associated deformation and metamorphism occurred in the Cambrian, with post-collisional magmatism in the Upper Cambrian. The structural style becomes increasingly complex from west to east. Up to three overprinted coaxial folding phases are observed with north / south upright axial planes dipping to east and axes plunging gently to North or South. A system of thrust faults is associated with displacement of the hangwall to the west. Down-dip to oblique and strike-slip stretching lineations are also observed, with kinematic indicators showing movement varying from inverse to sinistral. This suggests that the collisional convergence toward the Rio Apa block which generated the mobile belt was not strictly frontal, but had some degree of obliquity, with convergence vectors around SSW - ENE. The Cuiabá Group mica-schists show the most complex structural style with three superimposed coaxial fold phases and more intense tectonic foliations. It is proposed that there would be time correlation between the S3 foliation in the mica-schists in the easternmost area, with the S2 foliation in the central area and the S1 cleavage at the limit of the cratonic area to the west. This pattern can be explained by the westward migration of the deformational front. It is suggestive that the main thrusts coincide with major basin boundaries, where greater variations in thickness and expression of the basal formations occur. During the basin inversion the thrusts probably reactivated the former main listric faults of the rift stage.

Le Tianshan est une orogène intracontinentale de près de 2000 km de long. Cette chaîne accommode jusqu'à 40% de la convergence entre l'Inde et l'Eurasie, jouant ainsi un rôle fondamental dans l'évolution de la déformation en Asie. De plus, malgré cette déformation intense et ses hauts reliefs, sa topographie reste irrégulière avec de nombreux bassins intrachaîne préservés. Elle représente ainsi un cas remarquable pour l'étude des processus orogéniques dynamiques hors équilibre et constitue une zone clé pour l'étude de la déformation en Asie. Depuis le début du Pléistocène, une aridité prononcée a permis une préservation de nombreux marqueurs morphologiques. Ces marqueurs ont localement subi des déformations d'origine tectonique. Ainsi, la datation par isotopes cosmogéniques de ces marqueurs et la quantification du raccourcissement à l'origine de leur déformation, a permis de connaître précisément les vitesses de raccourcissements quaternaires de nombreuses structures actives au travers l'ensemble du Tianshan oriental. À cela s'ajoutent ponctuellement des études des vitesses de raccourcissement depuis le Néogène, basées sur la modélisation géométrique de strates syntectoniques. Ces mesures nous ont permis de mieux contraindre les taux de déformation sur les piémonts Nord et Sud de la chaîne mais également dans le bassin intrachaîne de Bayanbuluk. Sur la base de ces observations, je propose que les vitesses observées actuellement par les mesures GPS ne soient acquises par la chaîne que depuis ~150 à 200 ka. Nous démontrons aussi qu'au minimum 15% du raccourcissement est accommodé dans les parties internes de la chaîne. Je soutiens ainsi l'hypothèse que cette chaîne reste dans un stade de croissance immature et hors-équilibre / The Tianshan range is a 2000-km-long tectonically active mountain range. The Tianshan plays a major role in the India-Asia collision since it presently accommodates up to 40% of the total convergence between those two continents. Despite this intense deformation, the topography of the range shows series of high elevated range separated by flat intermountain basins. This range is therefore a remarkable case of example to study orogenesis processes and remains a key area to better understand how the deformation related to the India collision has been distributed through the Asian continent. Enhanced aridity since Pleistocene has moreover remarkably preserved alluvial terraces and fans which may have recorded the deformation enabling the quantification of the tectonic rates during the Quaternary period. Therefore, using Terrestrial Cosmogenic Nuclide we have dated several alluvial surfaces and analyzed their deformation using D.E.M. or high resolution DGPS measurements. Hence, in the eastern Tianshan we quantify the quaternary shortening rates across several structures located in the Northern and Southern foreland piedmonts but also within the range in the intermountain Bayanbuluk basin. Moreover, when possible we have also derived the Neogene shortening rates from geometric modeling of syntectonic strata. Our results highlight the recent acceleration of the eastern Tianshan since ~150-200 ka. We also show that a significant proportion (>15%) of the whole deformation is accommodated within the range while the remaining part is distributed between the different thin skin tectonic structure in the piedmonts. This result supports the hypothesis that the range is out of equilibrium and an in-building stage of deformation

Alkalic porphyry style Au-Cu deposits of the Cadia district are associated with Late-Ordovician monzonite intrusions, which were emplaced during the final phase of Macquarie Arc magmatism at the end of the Benambran Orogeny. N-striking faults, including the curviplanar, northerly striking, moderately west-dipping basement thrust faults of the Cadiangullong system, developed early in the district history. NE-striking faults formed during rifting in the late Silurian. Subsequent E-W directed Siluro- Devonian extension followed by regional E-W shortening during the Devonian Tabberabberan Orogeny dismembered these intrusions, thereby superposing different levels porphyry Au-Cu systems as well as the host stratigraphy. During the late Silurian, the partially exhumed porphyry systems were buried beneath the Waugoola Group sedimentary cover sequence, which is generally preserved in the footwall of the Cadiangullong thrust fault system. The Waugoola Group is a typical rift-sag sequence, deposited initially in local fault-bounded basins which then transitioned to a gradually shallowing marine environment as local topography was overwhelmed. Basin geometry was controlled by pre-existing basement structures, which were subsequently inverted during the Devonian Tabberabberan Orogeny, offsetting the unconformity by up to 300m vertically. In the Waugoola Group cover, this shortening was accommodated via a complex network of minor detachments that strike parallel to major underlying basement faults. For this reason, faults and folds measured at the surface in the sedimentary cover can be used as a predictive tool to infer basement structures at depth. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The aim of this study was to describe the laryngeal anatomy, perceptual, acoustic and aerodynamic vocal characteristics of school-aged children with and without ADHD. The predisposition that children with ADHD have for laryngeal injuries are recurrent in nature and are more often than not overlooked as laryngitis. Previous studies have reported varied results on the prevalence rates of paediatric VFN within the school-aged ADHD population. A static, two-group comparison was used in the study to investigate the clinical, perceptual, acoustic and aerodynamic vocal characteristics of children between 7 and 9 years old with and without ADHD. The study replicated the protocol as executed by Barona-Lleo and Fernandez (2016) with additions. The Multidimensional Voice Program (MDVP) and the Voice Range Profile (VRP) as additions to the assessment of vocal parameters were used with which comparable dysphonia severity index (DSI) scores were calculated. Once-off clinical, perceptual, acoustic and aerodynamic voice assessments were conducted on 20 age-gender matched participants. The difference in assessment results between the vocal characteristics of children without a history of ADHD (control group) and those of children with ADHD (ADHD group) was then investigated and described. Forty five percent (n=9) of the total sample population had laryngeal pathology. Comparable parent reported etiological voice symptoms and vocal habits were seen across both groups. Both groups performed similarly across both perceptual and aerodynamic voice assessments. Acoustically, the control group achieved significantly higher producible pitches than the ADHD group (p=0.028) and were found to have more dysphonic DSI scores than their ADHD group peers (p=0.034). Prepubertal, school-aged children with or without ADHD may have similar vocal characteristics than previously thought. This variation in school-aged children warrants further research into larger sample sizes with this population with a special focus on the effect that CNS stimulants may have on the voice. / Dissertation (MCommunication Pathology)--University of Pretoria, 2019. / Speech-Language Pathology and Audiology / MCommunication Pathology / Unrestricted

Previous studies have found vocal fold hydration to be crucial for healthy function of the vocal mechanism. Surface tissue hydration facilitates efficient vocal fold oscillation. The composition of vocal fold surface fluid includes protective water and mucus layers, similar to the fluid that covers the mucosa and epithelia of the upper airway. Laryngeal dehydration has been linked to several factors such as mouth breathing, obstructive sleep apnea, dry air exposure, upper airway hypersensitivity, and certain diseases or behavioral voice use factors. Laryngeal dehydration affects phonation threshold pressure (PTP) and phonation threshold flow (PTF), defined as the pressure and flow observed at the onset of phonation, respectively. The application of topical nebulized isotonic saline (0.9% Na+Cl-) has been shown in previous work to decrease PTP. However, there are no studies examining the effects of aerosolized saline, administered supraglottally, on dehydrated excised porcine larynges. Examining the effects of aerosolized saline in an excised model is essential to determine any independent effects of this treatment in the absence of other physiologic mechanisms such as mucus secretion. This study sought to investigate the effects of aerosolized saline on dehydrated animal vocal folds to determine if the administration of supraglottic aerosolized saline, via a nebulizer, could reverse the adverse effects of laryngeal dehydration. The study included a prospective, mixed experimental design with two groups, one desiccation/aerosolization (A/B) group and a control (A) group, each comprised of five bench-mounted porcine larynges. Larynges in both groups received desiccated air (<1% relative humidity) supraglottally via custom tubing for 1-min doses until the vocal folds ceased audible phonation. Following the desiccation challenge, the A/B group received 2-min doses of aerosolized isotonic saline until phonation began again. The PTP and PTF were measured during phonation trials following each dose of the desiccation or aerosolization treatment. Significant changes in PTP and PTF were observed following both the dehydration and aerosolization treatment. The PTP increased significantly following the dehydration challenge and returned near baseline following the aerosolization treatment. The results of this investigation supported the hypothesis that the administration of aerosolized saline may reverse the adverse effects of vocal fold dehydration. Moreover, in a more physiologically realistic excised model, applying the mechanics of respiration, this study advanced the development of innovative theories related to the reversal of the adverse effects of dehydration, which may prevent the development of voice disorders.