Émille Dalbem Paim,Felipe de Oliveira Goulart,Vera Beatris Martins,Fernanda Tormen Korspalski,Fabrício Edler Macagnan, Orofacial Myofunctional Therapy with and without Photobiomodulation in the Rehabilitation of Radiation-Induced Trismus: Case Series International Journal of Cancer Science and Therapy 2022 http://dx.doi.org/10.31487/j.IJCST.2022.03.02 https://www.sciencerepository.org/orofacial-myofunctional-therapy-with_IJCST-2022-3-102 Abstract: Photobiomodulation (PBM) as a therapeutic technology is justified by the biochemical changes caused in the intracellular environment, such as increased production of adenosine triphosphate and activation of antioxidant enzymes, allowing early recovery and maintenance of the homeostasis and proper functioning. This case report aimed to describe the effect of orofacial myofunctional therapy associated or not with photobiomodulation in the rehabilitation of radio-induced trismus in 6 patients. Two intervention modalities were performed, with three patients undergoing OMT isolated and the other two subjects undergoing oral myofunctional therapy associated with photobiomodulation therapy (OMT+PBM). All participants completed the radiotherapy between 3 and 15 months before starting the trismus rehabilitation. The mouth opening was 21.00mm for the patients who underwent exclusive OMT and reached 30.25mm at the end of the rehabilitation (difference of 9.25mm), but for the other three patients submitted to OMT+PBM, it went from 8.4mm to 31.5mm (difference of 23,1mm). It was observed that patients who performed PBM+OMT had greater tolerance to the protocol exercises and less pain report. OMT+PBM was a good combination for trismus rehabilitation and could be considered in further randomized clinical trials.Keywords: Head and neck neoplasms, masseter muscle spasm, exercise therapy, radiation-induced fibrosis