Provável bruxismo do sono em crianças de 8 a 10 anos de idade e fatores associados: um estudo de caso-controle

Abstract

Bruxism is a repetitive activity of the jaw muscles characterized by clenching and/or grinding the teeth. This activity can occur during sleep (sleep bruxism) or during wakefulness (awake bruxism) and can affect children and adults. The aim of the present study was to evaluate the association between probable sleep bruxism (SB) and socio-demographic factors, mothers stress, childhood stress and harmful oral habits in schoolchildren. A case-control study nested in a cross-sectional study was conducted involving a representative sample of 326 schoolchildren aged eight to ten years in the city of Diamantina, Brazil. The case (children with probable sleep bruxism) and control (children without probable sleep bruxism) groups were matched for age and sex at a proportion of 1:1 (163 cases and 163 controls). Information on audible sounds characteristic of sleep bruxism, harmful oral habits and demographic characteristics (parents/caregivers level of education, monthly household income, duration of monthly household income, number of children in the family and childs order of birth) were obtained through the use of questionnaires filled out by the parents/caregivers. The mothers filled out Lipps Stress Symptoms Inventory (LSSI) for adults and the schoolchildren filled out the Child Stress Scale (CSS). The children were submitted to clinical oral examinations to assess the presence/absence of tooth wear and/or muscle discomfort. Clinical examinations were conducted by a single examiner previously trained and calibrated to determine tooth wear and muscle discomfort (intra-examiner Kappa 0.74 and 0.82, respectively; inter-examiner Kappa 0.86 and 0.77, respectively). The diagnosis of probable sleep bruxism was based on the criterion of the international consensus (parental report and clinical examination). Data analysis included descriptive statistics, as well as unadjusted and adjusted conditional logistic regression analyses [(p0.05; 95% confidence interval (CI)]. Among the children with stress (n = 57), 64.9% (n = 37) had probable SB. The adjusted conditional logistical regression analysis revealed that children with stress (OR=2.00, 95% CI: 1.08-3.70; p=0.026) and those with the habit of nail biting (OR=2.19, 95% CI: 1.38-3.48; p=0.001) or biting objects (OR= 1.74 95% CI: 1.08-2.81; p=0.023) had a greater likelihood to present signs of probable sleep bruxism. Socio- demographic factors (schooling, monthly household income, duration of monthly income, number of children in the family and childs birth order), mothers stress and a history of pacifier use, lip sucking and thumb/finger sucking were not associated with probable SB. In conclusion, childhood stress and a history of nail biting or biting objects are important signs to be considered in schoolchildren with probable sleep bruxism.