Quantitative histological analysis of the mandibular branch of the facial nerve in rats Análise histológica quantitativa do ramo mandibular do nervo facial em ratos

PURPOSE: To establish a model to quantitative histological analysis of the mandibular branch of the facial nerve in rats. METHODS: Eleven Wistar rats had their right and left mandibular branches of the facial nerve surgically removed and were sacrificed afterwards. Quantitative histological analysis was performed with: a) partial number of axons; b) partial area of the transversal cut of the nerve (9000&#956;m²); c) partial density. The averages of partial density were obtained. The statistical study was established by Wilcoxon test (p=0.05). RESULTS: In relation to density of axons, comparison between sides shows no statistically significant difference (p=0.248; p=0.533). Mean partial density of distal and proximal samples was, respectively, 0.18 ± 0.02 and 0.19 ± 0.02 axons/&#956;m². Comparison between proximal and distal samples shows no statistically significant difference (p=0.859; p=0.182). CONCLUSION: This study has successfully established a model to histological quantitative analysis of the mandibular branch of the facial nerve in rats.<br>OBJETIVO: Estabelecer um modelo para análise histológica quantitativa do ramo mandibular do nervo facial de ratos. MÉTODOS: Onze ratos Wistar tiveram os ramos mandibulares de seus nervos faciais direito e esquerdo removidos cirurgicamente, e submetidos à análise histológica quantitativa de suas regiões proximal e distal com: a) contagem total do número de axônios, b) medida da área parcial (9000&#956;m²) de corte transversal do nervo, c) cálculo de densidade parcial (DP). RESULTADOS: Em relação à densidade dos axônios, a comparação entre os lados não mostrou diferença estatisticamente significativa (p=0,248; p=0,533). A densidade parcial média das amostras distais e proximais foi, respectivamente, 0,18 ± 0,02 e 0,19 ± 0,02 axônios/&#956;m². A comparação entre as amostras proximais e distais não mostrou diferença estatisticamente significativa (p=0,859; p=0,182). CONCLUSÃO: Este estudo estabeleceu com sucesso um modelo de análise histológica quantitativa do ramo mandibular do nervo facial em ratos

Tonsillotomy by a Fractional Carbon Dioxide Laser: A New Technique in the Treatment of Chronic Tonsillitis: Fractional Carbon Dioxide Laser Controls Chronic Tonsillitis

Introduction: chronic tonsillitis has a global prevalence ranging from 5-12%. Its clinical manifestations, like recurrent acute tonsillitis, tonsils hypertrophy, caseum and halitosis, can lead adult patients to be submitted to palatine tonsillectomy, surgery that has morbidity and the potential risk of complications, including severe bleeding. This article proposes a new therapy for chronic tonsillitis in adult patients using a&nbsp; &nbsp;fractional carbon dioxide (CO2) laser, a fast, minimally invasive procedure capable of removing the need for the traditional tonsillectomy in many patients. &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Objective: to verify the efficacy of tonsillotomy by fractional ablation using the CO2 laser by comparing number of bacterial infections, tonsils hypertrophy, halitosis and caseum; to analyze the benefits, risks and complications of the technique.&nbsp; Methods: 20 patients were subjected to one session of tonsillotomy by fractional ablation and were followed up on for a year. The control group was formed by the same patients in the pre-procedure period (one year) without treatment. Results: no complications occurred, the procedure was fast (30 seconds), safe and tolerated well without general anesthesia. After one year, there was a total remission of recurrent acute tonsillitis in 95% of the patients, and after six months there was a statistically significant improvement of halitosis and caseum, and tonsils size reduction (p&lt;0,05).&nbsp; The level of satisfaction average was 10 after three months and 8 after one year. Conclusion: tonsillotomy by fractional ablation using the CO2 laser is a safe, efficient procedure for chronic tonsillitis in adults, which can be incorporated into the daily clinical practice

Assessment of a Neurophysiological Model of the Mandibular Branch of the Facial Nerve in Rats by Electromyography

Objectives: Our objective was to develop an experimental model for the noninvasive and objective evaluation of facial nerve regeneration in rats using a motor nerve conduction test (electromyography). Methods: Twenty-two rats were submitted to neurophysiological evaluation using motor nerve conduction of the mandibular branch of the facial nerve to obtain the compound muscle action potentials (CMAPs). To record the CM APs, we used two needle electrodes that were inserted into the lower lip muscle of the rat. A supramaximal electrical stimulus was applied, and the values of CMAP latency, amplitude, length, area, and stimulus intensity obtained from each side were compared by use of the Wilcoxon test. Results: There was no significant difference (all p &gt; 0.05) in latency, amplitude, duration, area, or intensity of stimuli between the two sides. The amplitudes ranged between 1.61 and 8.30 mV, the latencies between 1.03 and 1.97 ms, and the stimulus intensities between 1.50 and 2.90 mA. Conclusions: This is a noninvasive, easy, and highly reproducible method that contributes to an improvement of the techniques previously described and may contribute to future studies of the degeneration and regeneration of the facial nerve.Sao Paulo FoundationSao Paulo Foundatio

Tubo de ácido poliglicólico e GM1 na regeneração de nervos periféricos Polyglycolic acid tube associated with GM1 in regeneration of peripheral nerves

INTRODUÇÃO: A auto-enxertia de nervo é considerada tratamento de escolha nas grandes perdas de tecido neural que não permitam a reparação através de anastomose primária. Nesses casos, o tubo sintético à base de ácido poliglicólico é uma alternativa para enxertia de nervo. Por outro lado, muitos estudos têm enfatizado a importância dos fatores neurotróficos na regeneração neural: o monossialotetraesosilgangliosídeo (GM1), um dos principais glicoesfingolípides do tecido nervoso de mamíferos, é tido como potencializador dos efeitos desses fatores. OBJETIVO: Comparar, em ratos, o grau de regeneração neural, utilizando análise histológica, contagem do número de axônios mielinizados regenerados e análise funcional com a utilização do neurotubo e do GM1. MÉTODOS: Essa avaliação foi obtida com a interposição de enxerto autógeno (grupo A), tubo de ácido poliglicólico (grupo B) e da associação do tubo de ácido poliglicólico à administração de GM1 (grupo C) em defeitos de 5 mm no nervo ciático. RESULTADOS: Foi observada formação de neuroma apenas no grupo A. Os grupos A e C apresentaram padrões histológicos semelhantes, exceto que os axônios regenerados do grupo C apresentavam-se mais organizados e mielinizados que o grupo A. CONCLUSÃO: Na recuperação funcional, não houve diferença estatisticamente significativa entre os três grupos, a despeito das diferenças histológicas qualitativas e quantitativas verificadas.<br>INTRODUCTION: Nerve allografting is regarded as a treatment of choice in large neural tissue losses preventing repair by primary anastomosis. In these cases, a synthetic polyglycolic acid tube is an alternative for nerve grafting. On the other hand, several studies have emphasized the importance of neurotrophic factors on neural regeneration, including substances with potential to optimize neural regeneration, especially the GM1, an neurotrophic enhancer factor. OBJECTIVE: to compare, in rats, the neural regeneration degree using histological analysis, regenerated myelinized axons count, and functional analysis with the use of neurotube and GM1. METHODS: This assessment was performed by interposing allograft (group A), polyglycolic acid tube (group B) and polyglycolic acid tube associated to GM1 (group C) on 5-mm sciatic nerve defects. RESULTS: Neuroma formation was found only on group A. Groups A and C showed similar histological patterns, except for the regenerated axons on group C, which were shown to be better organized and myelinized than in group A. CONCLUSION: on functional recovery, no statistically significant difference was found for the three groups, despite of qualitative and quantitative histological differences found

Regeneração pós-traumática do nervo facial em coelhos Posttraumatic facial nerve regeneration in rabbits

A paralisia facial periférica traumática constitui-se em afecção freqüente. OBJETIVO: estudo da regeneração pós-traumática do nervo facial em coelhos, por avaliação funcional histológica dos nervos traumatizados comparados aos normais contralaterais. METODOLOGIA: Vinte coelhos foram submetidos à compressão do tronco do nervo facial esquerdo e sacrificados após duas (grupo AL), quatro (BL) e seis (CL) semanas da lesão. A comparação entre os grupos foi feita pelas densidades total e parcial de axônios mielinizados. ESTUDO ESTATÍSTICO: método de Tukey (p < 0,05). RESULTADOS: Houve recuperação funcional parcial após duas, e completa após cinco semanas. Na análise qualitativa, verificou-se em AL um padrão degenerativo, com maior processo inflamatório tecidual. Em BL, sinais de regeneração neural, praticamente completa em CL. Os nervos normais (N) apresentaram DT média de 15705,59 e DP média de 21800,75. O grupo BL revelou DT média de 10818,55 e DP média de 15340,56 e o CL, DT média de 13920,36 e DP média de 16589,15. BL obteve 68,88%, e o grupo CL, 88,63% da DT de N. N mostrou DP maior que os lesados; porém, esta não evidenciou diferença estatística entre BL e CL. A DT dos nervos revelou-se um método analítico mais fidedigno do que a DP estudada.<br>Posttraumatic facial paralysis is a frequent disease. This work studies posttraumatic regeneration of the facial nerve in rabbits. Functional and histological analysis compared injured and normal nerves on opposite sides. The left facial nerve trunk of twenty rabbits were subjectedto compression lesion, and sacrificed after two (subgroup AL), four (BL) and six (CL) weeks. Comparison between groups was made by analysing total and partial densities of myelinated axons. STATISTICAL ANALYSIS: Tukey Method (p<0.05). RESULTS:There was partial functional recovery after two weeks, and complete recovery after five weeks. Qualitative analysis demonstrated a degenerative pattern in the AL group, with an increased tissue inflammatory process. Evident regeneration signs were observed in the BL group, and almost complete regeneration was seen in the CL group. Normal nerves (N) had an average TD of 15705.59 and average PD of 21800.75. The BL group had an average TD of 10818.55 and an average PD of 15340.56. The CL group had an average TD of 13920.36 and an average PD of 16589.15. The BL group had an average TD of N equal to 68.88%, and the CL group had an average TD of N equal to 88,63% (statistically significant). N showed a significant higher PD than injured nerves. However, this was not statistically different between BL and CL subgroups. Nerve DT was a more reliable method than PD in this study