Twelve laser applications will be applied as initial treatment, with 2 sessions per week. A wave length of 780 nm, with an energy density of 25 J/cm2, a power of 50 mW and power density of 1.25 W/cm2, will be used for a duration of 20 seconds per point, resulting in a total energy of 1J per point. The laser will be applied at each point, using a conventional tip in contact with the skin, thus considering an area of 0.04 cm2, in accordance with the protocol suggested by Venezian et al. (2010) and Carvalho et al. (2010). The laser will be applied to 3 points of the masseter muscle (upper, middle, and lower bundles) and 1 point in the anterior temporalis on each side of the face

The group undergoing treatment with occlusal plates will be instructed to use the device during sleep, 8 hours per night, for a period of 12 months. The plates will be made following the principles established by Okenson (1998).

Participants will be molded with alginate to obtain models. In the upper model, a 2 mm acetate plate will be made, to be later replaced with acrylic resin (STRINI et al., 2009), and these plates will be adjusted in centric relation, to promote occlusal stability and disocclusion guide.

Weekly follow-up and adjustments will be performed during the evaluation period, until the completion of treatment

For the placebo group, all the measures described for the group 1 (LIL) will be adopted, however the laser equipment will remain switched off.

Laser applications will be applied as initial treatment, with 2 sessions per week. A wave length of 780 nm, with an energy density of 25 J/cm2, a power of 50 mW and power density of 1.25 W/cm2, will be used for a duration of 20 seconds per point, resulting in a total energy of 1J per point. The laser will be applied at each point, using a conventional tip in contact with the skin, thus considering an area of 0.04 cm2

Muscle pain will be analyzed by clinical criteria of the Research Diagnostic Criteria for Temporomandibular Disorders

This phase of the study will consist in the quantification of resources, i.e. determining the frequency of use of resources and materials during the treatment. The units used to quantify the direct costs consumed are physical units such as consultation time, number of sessions, equipment used, and materials consumed. These data will be collected using a specific form.