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Biomedical subjects

Marcos Grellet

Publications and source records attributed to Marcos Grellet.

2 recordsLinked to original sources

[Vocal fold superficial layer of lamina propria histology after the position of mucosa pediculated flap: canine experimental study].

UNLABELLED: Many techniques were applied to treat patients with sulcus vocalis and scarred vocal folds. Their results were not good enough. In the Technique of Vocal Fold Pediculated Mucosa Flap, an anterior pediculated flap of vocal fold is positioned on the superficial layer of the lamina propria, below the free margin. AIM: To describe histological postoperative findings on the superficial layer of lamina propria during the application of the technique Vocal Fold Pediculated Mucosa Flap. The following parameters were compared between tested and control groups: total, type I and type III collagen and number of cellular nucleus. STUDY DESIGN: experimental. MATERIAL AND METHOD: Fifteen dogs were used. One vocal fold was submitted to the intervention and the other was left as control. Each group of three dogs was sacrificed on 10, 30, 90, 180 and 360 days after the experimental surgery. Hematoxylin and eosin (H.E.) and Syrius Red were the staining techniques used. RESULTS: Type I and total collagen suggested increased results in the tested group on postoperative days 90 and 180, nevertheless there was statistical significance only on postoperative day 180 (p<0.05). Type III collagen group area was less significant than the control group on postoperative day 180 (p<0.05). The number of cellular nucleus was increased on the 10th postoperative day, but decreased after the 30th day. DISCUSSION: The findings about total and type I collagen and the amount of cellular nucleus on the superficial layer of lamina propria were similar to laryngeal postoperative studies in dogs. More complex studies would contribute with new data about the present subject.

Animals↗

A contribution to simulating a three-dimensional larynx model using the finite element method.

A three-dimensional model is presented to simulate the larynx during vocalization. The finite element method is used to calculate the airflow velocity and pressure along the larynx as well as tissue displacement. It is assumed that the larynx tissue is transversely isotropic and divided into three tissues: cover, ligament, and body. A contact-impact algorithm is incorporated to deal with the physics of the collision between both true vocal folds. The results show that the simulated larynx can reproduce the vertical and horizontal phase difference in the tissue movements and that the false vocal folds affect the pressure distribution over the larynx surfaces. The effects of exciting the larynx with different pressure drops are also investigated.

Humans↗