Research Article VariationofEnergyinPhotobiomodulationfortheControlof Radiotherapy-InducedOralMucositis:AClinicalStudyin HeadandNeckCancerPatients CizelenedoCarmoFaleirosVelosoGuedes, 1 SilasAntonioJuvenciodeFreitasFilho , 2 PauloRog´ eriodeFaria , 3 AdrianoMotaLoyola , 1 RobinsonSabino-Silva, 4 andS´ ergioVitorinoCardoso 1 1 Area of Pathology, School of Dentistry, Federal University of Uberlˆ andia, Uberlˆ andia, MG, Brazil 2 Department of Surgery, Stomatology, Pathology, and Radiology, Area of Pathology, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil 3 Department of Morphology, Biomedical Sciences Institute, Federal University of Uberlˆ andia, Uberlˆ andia, MG, Brazil 4 Department of Physiology, Biomedical Sciences Institute, Federal University of Uberlˆ andia, Uberlˆ andia, MG, Brazil Correspondence should be addressed to S´ ergio Vitorino Cardoso; sv.cardoso@ufu.br Received 15 November 2017; Accepted 10 January 2018; Published 22 February 2018 Academic Editor: Hani Mawardi Copyright © 2018 Cizelene do Carmo Faleiros Veloso Guedes et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Oral mucositis (OM) is a frequent and severe adverse effect of therapy against head and neck cancer. Photobiomodulation with the low-power laser is known to be effective against OM, but the diversity of protocols and the possibility of stimulating residual tumor cells are still obstacles. e present study aimed to compare two doses of laser energy delivered to the oral mucosa of patients under oncologic treatment for head and neck cancer, looking for differences in the control of mucositis, as well as in the frequency of tumoral recurrences. Fifty-eight patients undergoing radiotherapy were randomized into two groups, distinguished according to the energy delivered by laser irradiation, namely, 0.25 J and 1.0 J. e groups were compared according to frequency, severity, or duration of OM, as well as the frequency of tumoral recurrences. OM was significantly less frequent in patients receiving 1.0J of energy, but the groups did not differ regarding severity or duration of OM. Tumoral recurrence also did not vary significantly between the groups. Photobiomodulation with a higher dose of energy (1.0J versus 0.25J) is associated with better control of radiotherapy-induced OM and does not significantly increase the risk of neoplastic recurrence. 1.Introduction Oral mucositis (OM) is an acute and ulcerative in- flammation of the oropharyngeal mucosa caused by cyto- toxic cancer therapy [1]. It is one of the most common adverse effects of head and neck irradiation and is even more frequent when associated with chemotherapy [2]. e course of OM frequently leads to severe pain that is sufficiently severe to impair speech, eating, and swallowing, thus re- ducing the quality of life of the patients [3]. ese events can lead to hospital admission involving substantial additional costs and even interruption of oncologic treatment [4]. e injury to healthy tissue caused by irradiation and OM-related effects begins with cellular death triggered by direct damage to DNA, followed by intense oxidative stress [5]. Most of the injury has been associated with the latter effect, which activates and amplifies signaling pathways that leads to inflammation and apoptosis, thus resulting in ul- ceration and further damage inflicted by bacterial coloniza- tion on the surface of lesions [6, 7]. Improved irradiation techniques, control of comorbidities, and adequate oral hy- giene mitigate the burden of OM [8]. Furthermore, specific prophylactic substances have been proposed, such as mucosal protectors, steroidal and non-steroidal anti-inflammatory and Hindawi International Journal of Dentistry Volume 2018, Article ID 4579279, 6 pages https://doi.org/10.1155/2018/4579279