Fotobiomodulação como tratamento do processo inflamatório em pregas vocais: modelo experimental

Abstract

The voice is a mechanism which permits identification in terms of age, gender, physical structure as well as emotional condition, which changes according to the situation and context generated during the communication process. For this reason, injuries to this mechanism can represent not only physical problems, but also lead to psychological or even social problems. In this context, disturbances in voice production, called dysphonia, must be attributed to functional and / or organic lesions, which, in turn, lead to decreasing communication ability. Photobiomodulation (FBM) modulates inflammatory processes, thus this study aimed to evaluate the effects of FBM on an experimental model of dysphonia. Male Wistar rats were exposed to 90 min of inhalation of 1% formaldehyde (FA) inhalation. Two hours after induction of the inflammatory process, the animals were treated with diode laser, with wavelength (ʎ) of830 nm;output power (P) 100 mW; energy (E) of 2 J with time of 20 s, and radiant exposure (RE) of, 72 J/cm2. The animals underwent irradiation procedures, however, with the laser equipment off (SHAM group). Five animals from each group were euthanized, at times 24, 48 and 72 h after the end of the treatment. Samples were surgically removed and divided in half. A part for evaluation of inflammatory markers TNFα, IL-6 and IL-10; and one-half for morphological evaluation with optical coherence tomography (OCT). The results demonstrated that the experimental model induced vocal fold edema in the FBM and SHAM groups, but no statistically significant differences was found between FBM and SHAM. Twenty-four hours after treatment, the Laser group showed release of IL-10 when compared to the SHAM group. The level of the other inflammatory markers were similar between Laser and SHAM. In conclusion, the FBM did not produce modulation in the inflammatory process in vocal folds in these circumstances with the parameters used in this study.