A maxillary occlusal splint will be fabricated in colorless acrylic resin and used on the maxilla with palatal and occlusal coverage. Molds of the maxillary and mandibular arches will be made in alginate for the fabrication of plaster models with a semi-adjustable joint. The splint will first be fabricated with dental wax in two layers and adapted to the maxillary teeth. The splint will measure 3 mm in thickness and will have contact with all teeth in a centric relationship, distal occlusion of the posterior teeth in laterality and protrusion, avoiding interferences on the side of balance with the guide canine, extending in the vestibular to lingual direction enough to prevent perforation and increase resistance to impact. An expander will also be placed so that the splint can accompany craniofacial growth. Following the protocol established by Hachmann et al., the children will only use the splint at night for two months, with weekly adjustments of a quarter turn.46 Saliva will be collected on cotton swabs, which will be left in the mouth for two minutes. The cotton will then be placed into a centrifuge tube and the sample will be stored at -20° C until analysis.25 Salivary cortisol will be measured prior to therapy and on Day 50 to measure the degree of stress. Two collections will be performed in the home of the participant at 9 am and prior to going to sleep with at least one hour of fasting prior to the collection and will be followed with oral hygiene with water. The collection will be performed on a Sunday following the manufacturer's recommendations and will be delivered on the following Monday for analysis at University Nove de Julho (Brazil).