Bruxism is a repetitive activity of the masticatory muscles characterized by grinding and/or clenching one's teeth or parafunctional movements of the mandible. The aim of the proposed controlled clinical trial is to evaluate muscle activity, bite force and salivary cortisol in children aged six to eight years with bruxism. The children will be randomly allocated to four groups, each with 19 participants: Group 1 will receive low-level laser therapy at acupuncture points; Group 2 will use an occlusal splint; Group 3 will receive placebo laser therapy; and Group 4 will be the control group without bruxism. Low-level laser (786.94 nm, 0.04 cm2, 70 mW and 20 s per points) will be applied directly on the skin at six acupuncture points on each side. The BTS TMJOINT electromyograph will be used to determine muscle activity and a digital gnathodynamometer will be used to measure bite force. Two saliva collections will be performed in the participant's home at 9 am and prior to going to sleep, with at least one hour of fasting and followed by oral hygiene with water. Evaluations will be performed before as well as one and six months after treatment. The findings will be computed and submitted to statistical analysis. Descriptive statistics will be used first for the determination of point estimates, precision and validation using analysis of variance (ANOVA) for the evaluation of residuals and parametric tests will be used for the determination of pre-treatment conditions. Interval estimates will be used for the variables of interest to determine the prevision of the estimates and perform comparisons. When necessary, transformation methods or non-parametric tests will be used in the data analysis. The chi-square test, Student's t-test and ANOVA will be employed, with the level of significance set at 5% (p < 0.05).