Internalizing symptoms and sleep disturbances associated with sleep bruxism in preschoolers.

BACKGROUND AND OBJECTIVES: The presence of sleep bruxism (SB) has been associated with internalizing symptoms and sleep disturbances in school-aged children and adolescents. While manifestations of SB often start earlier in development, there is a lack of studies investigating such an association in younger age groups. Therefore, we assessed the association between SB frequency and (1) internalizing symptoms (anxiety and depression) and (2) sleep disturbances in preschoolers. METHODS: The study comprised 340 mother-child dyads from a longitudinal cohort. Inclusion criteria were full-term pregnancy (>36 weeks), absence of birth complications, absence of severe health issues, and completion of essential measures for the present study. Mothers completed the Children's Sleep Habits Questionnaire when their child was four and five years old. Generalized estimating equation models were used to investigate our main objectives. The models included family socioeconomic status, child's sex, time, child's nighttime sleep duration, and maternal depressive symptoms as covariables. RESULTS: More frequent possible SB was associated with more anxiety (B = 0.682, p = 0.009) and depressive symptoms (B = 0.439, p = 0.02) in preschoolers. More frequent possible SB was also associated with more sleep anxiety (B = 0.450, p = 0.002) and bedtime resistance (B = 0.489, p = 0.01) but not with sleep onset delay, sleep duration, and night wakings (p > 0.05). CONCLUSIONS: Frequent possible SB episodes in preschoolers may be an indicator of depressive and anxiety difficulties during this developmental period. Bedtime manifestations of internalizing difficulties (bedtime resistance and sleep anxiety) paired with frequent SB in children should warrant further assessment for depressive and anxiety symptoms in preschoolers.