Salivary cortisol levels and biological rhythm in schoolchildren with sleep bruxism.
Salivary cortisol levels and biological rhythms could be hypothesized as part of the multifactorial framework that explains bruxism etiology. The objective of this study was to examine salivary cortisol levels and biological rhythms in schoolchildren with sleep bruxism (SB). This is a cross-sectional study with a school-based sample. The Biological Rhythms Interview for Assessment in Neuropsychiatry for Kids (BRIAN-K) was used to evaluate biological rhythms. Salivary samples were collected by the spitting method. The salivary cortisol level was measured by electrochemiluminescence. The criteria proposed by the American Academy of Sleep Medicine (AASM) were used to evaluate SB. The SB prevalence was 16%. The SB presence was associated with belonging to families of lower economic status (p = 0.003). In addition, children with SB showed greater difficulty in maintaining biological rhythm (p = 0.002) and had higher levels of salivary cortisol (p = 0.034) compared with children without SB. Higher levels of cortisol and disruption of biological rhythm was associated with SB in schoolchildren.