Immediate effects of photobiomodulation on maximum lip pressure

PURPOSE: To verify the immediate effects of different doses of photobiomodulation on maximum lip pressure. METHODS: Experimental, randomized and triple-blind study. The sample consisted of 23 women and 17 men, age between 18 and 33 years old (average 23.18 years old, SD=2.1), distributed in four groups: CG (control group), G1, G4 and G7. The maximum pressure was assessed with the Iowa Oral Performance Instrument (IOPI). The bulb was placed between the lips and the participants were instructed to press it as strong as possible. Infrared LASER (808 nm), manufactured by DMC, Therapy EC model, 100 mW of power output, was applied. The doses tested were 1 J (G1), 4 J (G4) and 7 J (G7), applied at six points of the orbicularis oris muscle. In the CG there was no intervention. The evaluation procedures were repeated after the LASER application. The results were analyzed with a significance level of 95%. RESULTS: The maximum lip pressure increased significantly only in the group irradiated with 7 J. CONCLUSION: Low level LASER therapy with 7 J dose promoted changes in the performance of the orbicularis oris muscle in the maximum pressure task.