The main characteristic of an individual with Trisomy 21 (T21), commonly known as Down Syndrome (DS), is muscular hypotonia, a characteristic that mainly affects the masticatory and oropharyngeal muscles, resulting in impairments in speech, swallowing, breathing and chewing, in addition to pain, noise and/or degeneration in the temporomandibular joints (TMJ), therefore, developing bruxism. The gold standard for the treatment and control of bruxism is the rigid plate, however, there is difficulty in developing treatment in children and adolescents with T21, therefore, photobiomodulation is a non-invasive intervention alternative already consolidated as an excellent option for modulation in muscle tissues. This study sought to evaluate the efficacy and safety of non-invasive intervention with red LED clusters for the control of bruxism in children and adolescents diagnosed with Down Syndrome. The present study is characterized as a pilot study, composed of individuals of both sexes, aged 4 to 17 years old, attended at the UNINOVE integrated health clinic and diagnosed with Down syndrome and bruxism. The treatment was carried out in a total of four sessions, one session per week, where in each session the LED plates were applied and post-application electromyographic collection was carried out.

Inclusion Criteria:

• Children and adolescents with a diagnosis of Down syndrome
• Four to 17 years of age
• Bruxism, based on parental reports of the occurrence of grinding the teeth, incisal and/or occlusal tooth wear following the criteria of the American Academy of Sleep Medicine (AASM) and the questionnaire for the evaluation of bruxism validated by Serra Negra et al. (2014) and a systematic review performed by Manfredini et al. (2013).

Exclusion Criteria:

• Use of muscle relaxant
• Temporomandibular disorder
• Undergoing other therapy for bruxism
• Other associated neurological diseases
• Cognitive deficit that impedes understanding the evaluations.