Reported prevalence of sleep bruxism—clenching and/or grinding of the teeth at night—varies greatly among different societies. To determine factors associated with sleep bruxism in 3-to 5-year-old children, Vieira-Andrade et al from the Federal University of Minas Gerais, Brazil, conducted a cross-sectional study of 749 patients for various malocclusions and evaluated the presence of bruxism, along with oral habits, medical history, birth information and sociodemo-graphic factors, through parental interviews; nutritional status was determined by anthropometric measures.

Bruxism was present in 103 of the preschool children (13.8%); malocclusion was present in 258 (34.4%). Biting on objects, lower arch crowding, brachyfacial type and having a mother with >8 years of school were significantly associated with sleep bruxism. In the adjusted multivariate regression, lower arch crowding (prevalence ratio [PR], 3.38; 95% confidence interval [CI], 1.9–5.7), biting on objects (PR, 2.49; 95% CI, 1.4–4.4), breastfeeding >12 months (PR, 1.98; 95% CI, 1.2–3.2) and bottle feeding for >24 months (PR, 1.93; 95% CI, 1.2–3.1) were significantly associated with sleep bruxism.

Biting on objects is a way preschool children relieve emotion and psychological stress. That may explain its connection to sleep bruxism, which has been associated with stress, anxiety, aggressiveness and hyperactivity. The greater prevalence among children breastfed 12 months may simply reflect the fact that these children tend to sleep in their parents’ bed more frequently, giving their parents more chances to observe sleep bruxism.

Vieira-Andrade RG, Drummond CL, Martins-Júnior PA, et al. Prevalence of sleep bruxism and associated factors in preschool children. Pediatr Dent 2014;36: 46-50.