Is There an Increase in Possible Sleep Bruxism in Children Over Time? A Longitudinal Study.

BACKGROUND: Bruxism is a behaviour that has several consequences in an individual's life, especially when it starts in childhood. However, bruxism can be a potential protective factor, which is an attribute that reduces the chance of a negative health outcome. OBJECTIVES: To evaluate the incidence of sleep bruxism (SB) and dental wear in children and adolescents. MATERIALS AND METHODS: This longitudinal study began in 2014 and 2016 (baseline) with initial 1816 children followed for 5 and 3 years, respectively. The follow-up data collection started in 2019. The diagnosis of SB was parents report (baseline) and self-report (follow-up) due to age groups of each phase, and questions related to symptoms of SB were collected. Five calibrated examiners (kappa >0.7) collected the clinical data. The clinical variables were dental erosion and dental wear. Contextual, individual, behaviour and clinical characteristics were collected. A multilevel logistic regression model was used to investigate the association of contextual, individual, behaviour and clinical characteristics with SB. Poisson regression for repeated measures was performed to evaluate the incidence of SB and dental wear (incidence rate ratio-IRR and confidence interval-95% CI). RESULTS: Two hundred and fifty-three children and adolescents answered questionnaires and were clinically examined. The mean age of the follow-up in 2019 was 11.25 years old (+/-2.19). There was no increase in the incidence of SB (95% CI: 0.74-1.35). Children/adolescents had a 2.2 higher risk to present dental wear (95% CI: 1.89-2.60). SB at the follow-up was associated with the contextual variable, earache, erosion and awake bruxism. CONCLUSIONS: In this population, children with SB remained with this behaviour and showed higher dental wear over the years.