Banca de DEFESA: Ana Carolina Nascimento Fernandes

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : Ana Carolina Nascimento Fernandes
DATE: 28/02/2024
TIME: 14:00
LOCAL: Auditório da Pós-Graduação da FM
TITLE:

Evaluation of the effect of low-power laser on the larynx of pigs

KEY WORDS:

Photobiomodulation. Acute and delayed effects. Laryngeal tissues. Histology. Morphometry

PAGES: 84
BIG AREA: Ciências da Saúde
AREA: Fonoaudiologia
SUMMARY:

During phonation, excessive use of the voice can lead to microlesions and inflammation, making it difficult for the mucous membrane to vibrate properly and altering voice quality. Vocal hygiene, phonatory effort reduction exercises and devices such as LLLT are used in clinical practice. The biomodulatory effect of LLLT in reducing pain and edema has been reported. The aim of this study was to evaluate the acute and delayed effects of 1 or 8 doses of RL and IRL, isolated or in combination, on the larynx of young and adult swines. MATERIALS AND METHODS: Descriptive and comparative, paired and unpaired, experimental, crosssectional and longitudinal study performed with swines randomly divided into 13 groups (n = 5) (CEUA/UnB 004/2020). The late effect of 1 or 8 doses of LLLTs was assessed in adult animals dosed 91 days before death, while the acute effect occurred in adult animals dosed between 24 hours (single dose) or 8 days (8 doses) before death. The study assessed laryngeal temperature in vivo before and after LLLTs (4 years) and histological aspects of laryngeal tissues (mucosal width, cells and extracellular matrix of connective tissue and striated muscle tissue of the vocal fold). Histological data were compiled and analysed using Prism 5.0® software. RESULTS: 1. Clinical evaluation: Young swines had a basal temperature 12% higher than adults. LLLTs isolated caused transient erythema and flushing. 2. Thermography: a single dose of VL increased temperature in juveniles, as did multiple doses of LLLTS; in adults, temperature increased with VL and with VL+VL with multiple doses. 3. Mucosal width: The acute effect of 1 dose of IRL reduced the mucosa (morphometry; IRL < RL+IRL and C) by reducing the oedema favoured by the effect of IRL (qualitative analysis); the acute effect of 8 doses of LLLTs reduced the mucosa (morphometry; LLLTs < C) by reducing oedema and increasing extracellular matrix production (CT) favoured by IRL; the late effect was seen in mucosal reduction with 1 dose of RL and LLLTs combined (RL and RL+IRL < C) and with 8 doses of LLLTs combined (RL+IRL < C). 4. Connective tissue: 1 dose of LLLTs (acute or delayed) did not affect the number of fibroblasts/fibrocytes, mitotic cells, expression of collagen, elastic and nerve fibres; 8 doses of LLLTs had no effect (acute) on the number of fibroblasts/fibrocytes and nerve fibres (LLLTs ≈ C), IRL increased collagen and elastic fibres (IRL > RL+IRL), mitotic cells were more numerous in combined LLLTs (RL+IRL > IRL and C); later, 8 doses of RL+IRL increased fibroblasts/fibrocytes (RL+IRL > RL, IRL and C), collagen (RL+IRL > RL and C) and elastic fibres (RL+IRL > C) and decreased cells in mitosis (RL+IRL < RL); RL increased nerve fibres (RL > C). 5. Vocal fold striated muscle: the acute and delayed effect of 1 dose of LLLTs caused hypertrophy (LLLTs > C) and decreased the total number of muscle fibres (LLLTs < C), but did not affect myonuclei, the integrity/juxtaposition of striated fibres, nerve fibres or mitotic cells (LLLTs ≈ C); acutely, 8 doses of LLLTs did not affect the total and integrity/juxtaposition of striated fibres (LLLTs ≈ C) but caused hypertrophy (LLLTs > C), isolated or in combination, LLLTs increased myonuclei (RL > C), nerve fibres (RL and RL+IRL > C) and cells in mitosis (RL+IRL > IRL); later, 8 doses of LLLTs did not affect total, integrity/adaptation of muscle fibres and cells in mitosis, laser isolated increased myonuclei (RL and IRL > C), IRL and LLLTs combined increased fibre area (RL and RL+IRL > C), RL increased nerve fibres (RL > C) and IRL increased myonuclei (IRL > RL and RL+IRL). CONCLUSION: In the light of these findings, the use of multiple doses is considered especially in the treatment of inflammatory dysphonia (nodules, polyps, edema, paresis and paralysis), while single or multiple doses improve function in individuals with high vocal demand.

COMMITTEE MEMBERS:
Interna - 3424061 - SELMA APARECIDA SOUZA KUCKELHAUS
Externo ao Programa - 2646005 - AMILCAR SABINO DAMAZO - UnBExterna ao Programa - 1142165 - ANA LUCIA CARNEIRO SARMENTO - UnBExterna à Instituição - MARIA DE LOURDES LAZZARI DE FREITAS - MEC
Externa à Instituição - THAIS TAMARA CASTRO E SOUZA MINUZZI - MS