Possible sleep bruxism and biological rhythm in school children

OBJECTIVE: To verify whether children with possible sleep bruxism (PSB) had alterations in biological rhythm and to explore the possible factors involved, such as sleep characteristics, screen time, breathing, sugary food consumption, and clenching teeth during wakefulness reported by parents/guardians. METHODOLOGY: Data were collected through online interviews with 178 parents/guardians of students aged 6 to14 years from Piracicaba, SP, BR, when the BRIAN-K scale was answered, which is composed of four domains (1) sleep; (2) daily routine activities; (3) social behavior; (4) eating; questions about predominant rhythms (willingness, concentration, and change day to night). Three groups were formed: (1) without PSB (WPSB), (2) with PSB sometimes (PSBS), and (3) with PSB frequently (PSBF). RESULTS: Sociodemographic variables were similar between groups (P > 0.05); the total value of the BRIAN-K was significantly higher for the PSBF group (P < 0.05); the first domain (sleep) presented significantly higher values for the PSB groups (P < 0.05); no significant difference for other domains and predominant rhythms occurred (P > 0.05). The involved factor that differed between groups was clenching teeth, as the number of children with PSBS was significantly higher (χ2, P = 0.005). The first domain of the BRIAN-K (P = 0.003; OR = 1.20), and clenching teeth (P = 0.048; OR = 2.04) were positively associated with PSB. CONCLUSION: Difficulties in maintaining sleep rhythm and clenching teeth during wakefulness reported by parents/guardians may determine a greater chance to increase the frequency of PSB. CLINICAL RELEVANCE: Good sleep seems to be important to maintain a regular biological rhythm and may reduce the frequency of PSB in the 6–14 age group. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00784-023-04900-y.