MUCILA

To assess the efficacy of preventive Low-Level Laser Therapy (LLLT) for reducing the incidence of WHOÀs grade 3-4 oral mucositis in children and young adults receiving chemotherapy regimens associated with a high rate of mucositis:;To assess the efficacy of preventive LLLT in children and young adults treated for cancer to:;À Reduce the severity of oral mucositis according to the Oral Assessment Guide (OAG) score;À Reduce the intensity of pain due to oral mucositis;À Reduce the impact of mucositis on behavior and oral function (food intake, complain, mouth opening, speaking and swallow functions);À Reduce the consumption of analgesics