No description available.

<p>Vocal fold vibration results in voice production. Optimal hydration levels contribute to self-sustained vocal fold vibration and preservation of voice quality. Adequate hydration is implicated as a factor in maintaining voice and preventing voice problems. Voice problems affect up to one third of adults during their lifetime. But whether altered hydration state adversely affects vocal fold biology and biomechanics is still unclear. To untangle the effects of systemic dehydration on vocal fold biology, we developed a water restriction protocol on lab animals that can translate to humans. Our results showed that dehydration induced by restricted water access downregulated the gene expression of IL-1α and desmoglein-1, upregulated the gene expression level of hyaluronidase-2, and downregulated hyaluronic acid (HA).</p> <p>Clinically, hydration treatments are hypothesized to maintain the viscoelastic properties of vocal folds. However, our understanding of the relationship between vocal fold tissue hydration level and biomechanical properties is still evolving. To investigate the effects of dehydration on biomechanical properties we used an ex vivo experimental design. We hypothesized that the optimal stiffness of vocal folds would be impacted after dehydration via losing both water and HA, but that the stiffness properties would recover through rehydration. To test this hypothesis, we experimentally treated porcine vocal fold samples using two different approaches: 1) immersion in hypertonic solution (15% NaCl in ddH2O) and PBS sequentially to mimic dehydration and rehydration, and 2) incubation with hyaluronidase (Hyal) to mimic HA loss during dehydration. Our results showed that loss of water increased tissue stiffness and could be recovered through rehydration in a certain degree. In addition, loss of HA increased tissue stiffness. </p> <p>In While dehydration decreases total body blood volume, different tissues and organs of the body may be impacted in different ways from dehydration. Therefore, it is important to investigate the hemodynamic alterations during changes to hydration status. Magnetic resonance angiography (MRA) and ultrasound imaging were employed to identify the delicate vascular geometry and hemodynamics of the laryngeal blood supply. Animals underwent both MRA and ultrasound imaging at baseline, dehydration and rehydration time points. Our results showed that dehydration impacted the blood supply to larynx. This blood supply was restored through rehydration treatment.</p> <p>Overall, this research has been successful in establishing a mild dehydration animal model, providing evidence from gene and protein levels that dehydration affects cytokine production and extracellular matrix components (ECM) in vocal fold, demonstrating the vocal fold tissue biomechanical behavior after dehydration and loss of HA, and offering a combination application of MRA and ultrasound imaging to study vascular geometry and hemodynamics of the blood supply to the vocal fold region.</p>

The human voice is a product of an intricate biophysical system. The complexity of this system enables a rich variety of possible sounds, but at the same time poses great challenges for quantitative voice analysis. For example, the vocal folds can vibrate in several different ways, leading to variations in the acoustic output. Because the vocal folds are relatively inaccessible, such variations are often difficult to account for. This work proposes a novel method for extracting non-invasively information on the vibratory state of the human vocal folds. Such information is important for creating a more complete voice analysis scheme. Invasive methods are undesirable because they often disturb the subjects and/or the studied phenomena, and they are also impractical in terms of accessibility and cost. A useful frame of reference for voice analysis is the Voice Range Profile (VRP). The 3 dimensional form of the VRP can be used to depict any phonatory metric over the 2 dimensional plane defined by the fundamental frequency of phonation (x-axis) and the sound pressure level (y-axis). The primary goal of this work was to incorporate information on the vibratory state of the vocal folds into the Voice Range Profile (e.g., as a color change). For this purpose, a novel method of analysis of the electroglottogram (EGG) was developed, using techniques from machine learning (clustering) and nonlinear time series analysis (sample entropy estimation). The analysis makes no prior assumptions on the nature of the EGG signal and does not rely on its absolute amplitude or frequency. Unlike time-domain methods, which typically define thresholds for quantifying EGG cycle metrics, the proposed method uses information from the entire cycle of each period. The analysis was applied in a variety of experimental conditions (constant vowel with different vibratory states, constant vibratory state and different vowels, constant vowel and vibratory state with varying lung volume) and the magnitude of effect on the EGG short-term spectrum was estimated for each of these conditions. It was found that the short-term spectrum of the EGG signal sufficed to discriminate between different phonatory configurations, such as modal and falsetto voice. It was found also that even supposedly purely articulatory changes could be traced in the spectrum of the EGG signal. Finally, possible pedagogical and clinical applications of the method are discussed. / <p>QC 20140609</p> / FonaDyn

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

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.

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

Vocal fold hydration is important for efficient oscillation during voice production. Dehydration of the vocal fold surface is believed to produce adverse effects on the voice. Specifically, low environmental humidity, mouth breathing, and certain medical conditions may contribute to laryngeal and vocal fold dehydration. This dehydration effect may be quantified using the observed pressure and flow at the onset of phonation, operationally defined as phonation threshold pressure (PTP) and phonation threshold flow (PTF), respectively. Previous research has documented that nebulized isotonic saline (0.9% Na+Cl-) can reduce PTP. Additionally, the topical application of liquid saline increases vocal fold hydration in excised larynx studies. However, no studies have examined the prevention of vocal fold dehydration using aerosolized saline in an excised larynx mechanical model. The purpose of the current investigation was to determine the preventive effects of aerosolized isotonic saline in a physiologically realistic excised larynx model. Using a prospective, mixed experimental design with a control group, five bench-mounted, excised porcine larynges received 4-min doses of aerosolized saline delivered supraglottally for a total of 24 min. Subsequently, larynges received 1-min doses of desiccated air (<1% relative humidity) delivered supraglottally. A control group of five porcine larynges received only desiccated air. Phonation was attempted following each dose of aerosolized saline or desiccated air. The desiccation doses were repeated for both groups until the larynges were no longer able to phonate. The PTP and PTF were measured at baseline and following each dose of aerosolized saline or desiccated air. Analysis of the results indicated that aerosolized saline significantly delayed the adverse effects of vocal fold dehydration based on the total number of desiccation doses required to cease phonation for experimental versus control groups (p = .002). Trends demonstrated that PTP decreased after aerosolized saline and increased during desiccation trials. The PTF trends were similar during desiccation. The results from this study indicate that aerosolized saline may be used prophylactically to prevent vocal fold dehydration. These findings offer important advances in vocal fold hydration theory and dehydration prevention in a physiologically realistic excised mechanical model.

Introduction et objectifs La microchirurgie des pathologies cordales bénignes est une chirurgie fonctionnelle dont le but est daméliorer les caractéristiques mécaniques du vibrateur laryngé. Une connaissance approfondie de la structure cordale normale, de ses altérations pathologiques et des implications bio-mécaniques de la structure tissulaire, est indispensable à la réalisation dune microchirurgie cordale de qualité. Cest grâce aux connaissances de plus en plus approfondies de la structure cordale normale et surtout de son tissu conjonctif, la lamina propria, que la microchirurgie cordale a évolué dune chirurgie de résection pure et simple à une chirurgie fonctionnelle. Cest la partie la plus superficielle de la lamina propria, lespace de Reinke, qui joue le rôle le plus important dans la production du son. Cest aussi lespace de Reinke qui est occupé, détruit ou remanié en cas de pathologie cordale bénigne. La microchirurgie vise à le libérer du processus pathologique. Cest en augmentant la souplesse tissulaire et la fermeture glottique en phonation que le micro-chirurgien espère améliorer les caractéristiques du son laryngé émis. Loriginalité de ce travail est de tenter, non seulement de libérer lespace vibrant de la lésion cordale, mais aussi de modifier les processus cicatriciels post-opératoires par lutilisation dun implant résorbable dacide hyaluronique estérifié. Les objectifs de ce travail sont : - de contribuer à la connaissance des résultats fonctionnels laryngés et vocaux que lon peut attendre dune microchirurgie cordale - dévaluer limpact fonctionnel, sur ces résultats, de lutilisation dun implant résorbable dacide hyaluronique estérifié, en fin dintervention chirurgicale. Caractéristiques méthodologiques Ce travail est une étude clinique, prospective et comparative. Lutilisation dun implant résorbable dacide hyaluronique estérifié en fin dintervention microchirurgicale est une technique originale développée depuis février 2003 et que nous continuons à pratiquer. Les arguments qui ont conduit à implanter de lacide hyaluronique estérifié au sein de lespace de Reinke de certaines cordes opérées, sont été exposés. Le résultat fonctionnel laryngé et vocal obtenu chez 33 patients opérés de différentes lésions cordales bénignes et traités par implantation dacide hyaluronique estérifié dans la plaie microchirurgicale en fin dintervention (groupe implanté), est comparé à celui de 50 patients également opérés de lésions cordales bénignes mais qui ne bénéficient pas dune implantation dacide hyaluronique estérifié (groupe non-implanté). Les patients ont été opérés entre février 2003 et décembre 2006. Deux études statistiques distinctes ont été pratiquées : 1) une analyse de variance comparant les données préopératoires aux données postopératoires immédiates 2) Les observations différées (en dehors de la période post-opératoire immédiate) sont analysées par une étude statistique corrélationnelle. Résultats La microchirurgie cordale des lésions bénignes savère être une chirurgie fonctionnelle efficace : elle améliore rapidement, dès le premier examen post-opératoire, la qualité vocale et le rendement phonatoire des patients opérés, et ce dans les deux groupes. Nos observations vidéo-stroboscopiques postopératoires précoces plaident en faveur de caractéristiques visco-élastiques favorables de limplant dacide hyaluronique estérifié. Si ce dernier sétait avéré trop visqueux ou trop rigide, nous aurions observé une absence dondulation muqueuse ou une détérioration de celle-ci lors du premier contrôle postopératoire. Mais une des originalités de notre travail est de réaliser un suivi clinique à long terme de lévolution vocale et laryngée de nos patients. Celle-ci est analysée par une étude statistique corrélationnelle non paramétrique. Un comportement très différent est observé: le groupe de patients implantés continue daméliorer 10 variables sur les 20 variables évaluées et quantifiées, alors que le groupe non-implanté naméliore significativement quune seule variable. Autrement dit, le groupe implanté manifeste une évolution significative et favorable au fil du temps, bien au-delà de la période post-opératoire immédiate. Le groupe contrôle, quant à lui, ne témoigne daucune évolution des paramètres vocaux et laryngés quantifiés lors de ce suivi à long terme. Lexplication de cette évolution différente pourrait être une atteinte plus sévère du groupe implanté, et donc une amélioration plus lente des paramètres vocaux et laryngés. Cela pourrait expliquer partiellement lévolution de G, R, S, I et des caractéristiques stroboscopiques droites qui étaient moins bonnes au sein du groupe implanté lors de lexamen pré-opératoire. Mais cette vision nous paraît insuffisante et réductrice : certaines variables étaient altérées de manière équivalente dans les deux groupes lors de lexamen préopératoire et névoluent favorablement quau sein du groupe implanté. Mais surtout, les deux groupes évoluent de la même manière lors du premier examen post-opératoire (analyse de variance des résultats post-opératoires immédiats, cf plus haut). Le groupe contrôle nest certes pas « normalisé » après la microchirurgie et sil ne sagissait que dune évolution retardée, elle devrait également sobserver dans le groupe contrôle. On peut donc raisonnablement envisager une action favorable de lacide hyaluronique estérifié sur le processus de cicatrisation intratissulaire : une lente amélioration de la souplesse de la couverture cordale se fait jour, grâce à une reconstitution au moins partielle dune matrice extracellulaire par des fibroblastes dont le phénotype a été modifié par la présence dun taux élevé dacide hyaluronique au sein de la plaie microchirurgicale. Nous pourrions donc expliquer lévolution particulière de notre groupe implanté par un véritable processus régénératif au sein de lespace de Reinke. Ce processus ne peut être que lent, connaissant le caractère pauci-cellulaire de cette couche tissulaire, et donc nest pas perceptible lors du premier contrôle post-opératoire : à ce moment, les deux groupes évoluent de manière identique. Conclusions Loriginalité de notre travail réside dans lutilisation dun dérivé dacide hyaluronique afin de moduler le processus de cicatrisation post-opératoire : cest la première fois que ce type de technique est mis en oeuvre, les travaux précédemment publiés par dautres auteurs ne portant que sur des études in vitro ou sur modèles animaux. Notre travail constitue dès lors un premier pas vers une microchirurgie cordale non pas seulement fonctionnelle, mais aussi régénérative. En effet, nous nous sommes appuyés sur linfluence bénéfique que peut exercer la composition de la matrice extracellulaire sur le fonctionnement cellulaire cordal. Les résultats obtenus sont très intéressants puisquils montrent une amélioration post-opératoire, non seulement précoce mais aussi retardée, chez des patients implantés dont la souplesse cordale était, en phase pré-opératoire, sévèrement altérée. Lamélioration continue observée, au fil dune longue période de temps, chez les seuls patients implantés, est à nos yeux le résultat le plus surprenant et le plus enthousiasmant. Cette observation constitue un argument important en faveur dun processus de cicatrisation régénératif dans lespace de Reinke traité par notre technique originale dimplantation dacide hyaluronique estérifié. Notre travail nous a permis dappréhender la complexité de la structure et de la physiologie tissulaire cordale. Il soulève aussi de nombreuses questions qui dans lavenir, doivent faire lobjet de projets de recherches fondamentales : quels sont les mécanismes de lhoméostasie de la composition de la matrice extracellulaire du tissu cordal sain ? quelles sont les dérégulations à lorigine du développement des pathologies cordales bénignes ? quelle est linfluence des contraintes mécaniques sur la composition matricielle cordale ? quelle est linfluence du bagage génétique sur le développement des lésions bénignes ? quels sont les processus de cicatrisation du tissu cordal humain ? De la même manière que par le passé, ce sont les connaissances approfondies de la structure laminaire cordale qui ont modifié le geste microchirurgical, ce sont les réponses à ces questions qui permetteront certainement à la microchirurgie cordale dévoluer vers une chirurgie de plus en plus régénérative.

No description available.

Darbo uždaviniai buvo: Nustatyti gerklų audinio MMP-2 ir MMP-9 raiškos pokyčius kai yra nepiktybiniai gerklų dariniai (balso klosčių polipai), ikivėžinė gerklų patologija (atsinaujinanti gerklų papilomatozė ir lėtinis hiperplazinis laringitas su keratoze) bei gerklų plokščių ląstelių karcinoma ir įvertinti šių pokyčių diagnozinę vertę. Įvertinti gerklų audinio MMP-2 ir MMP-9 raiškos pokyčių sąsajas su klinikiniais ir morfologiniais nepiktybinių gerklų darinių (balso klosčių polipai), ikivėžinės gerklų patologijos (atsinaujinanti gerklų papilomatozė ir lėtinis hiperplazinis laringitas su keratoze) bei gerklų plokščių ląstelių karcinomos požymiais. Palyginti matrikso metaloproteinazes koduojančių genų MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-9 (-1562 C/T) ir MMP-3 (-1171 5A/6A) polimorfizmo dažnį, kai yra organinės nepiktybinės gerklų ligos bei gerklų plokščių ląstelių karcinoma. Įvertinti matrikso metaloproteinazes koduojančių genų MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-9 (-1562 C/T) ir MMP-3 (-1171 5A/6A) polimorfizmo sąsajas su gerklų plokščių ląstelių karcinoma bei jos klinikiniais ir morfologiniais požymiais. / The goals of the study were as follows: 1. To determine the changes in the expression of the laryngeal tissues MMP-2 and MMP-9 in patients with benign laryngeal tumors (vocal fold polyps), precancerous laryngeal lesions (recurrent respiratory papillomatosis and laryngeal keratosis) and laryngeal squamous cell carcinoma, and assess the diagnostic value of the aforementioned changes. 2. To assess the correlations between the changes in the expression of the laryngeal tissues MMP-2 and MMP-9 and the clinical and morphologic indications of benign laryngeal tumors (vocal fold polyps), precancerous laryngeal lesions (recurrent respiratory papillomatosis and laryngeal keratosis) and laryngeal squamous cell carcinoma. 3. To compare the rate of MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-9 (-1562 C/T) and MMP-3 (-1171 5A/6A) gene polymorphism in cases of non-malignant laryngeal lesions and laryngeal squamous cell carcinoma. 4. To assess the association between MMP-2 (-735 C/T), MMP-2 (-1306 C/T), MMP-9 (-1562 C/T) and MMP-3 (-1171 5A/6A) gene polymorphism, the laryngeal squamous cell carcinoma as well as its clinical and morphologic indications.