Geographical variation of parental-reported sleep bruxism among children: comparison between the Netherlands, Armenia and Indonesia

Objective: The aim of this study was to investigate whether geographical variation exists in the prevalence rates and associated factors of parental-reported sleep bruxism (SB) among 7- to 12-year-old children living in three culturally different countries. Methods: An identical questionnaire was completed by parents or guardians of children in the Netherlands (Europe), Armenia (West Asia) and Indonesia (Southeast Asia). Pearson's chi-square tests were used to investigate geographical variation in occurrence; logistic regression analyses were performed to study associations. Results: In total, data of 2,562 questionnaires were analysed. The overall prevalence of parental-reported SB was significantly higher in Armenia (36.5%) than in the Netherlands and Indonesia (19.5% and 24.2%, respectively; P < 0.001). However, differences between countries seemed to have disappeared in children around the age of 12. Geographical variation in associated factors is reflected in the fact that, depending on the country, a variety of variables were positively related with parental-reported SB (i.e. younger age, and/or having male gender, and/or experiencing pressure or tension from the home situation, and/or being more easily scared and/or having difficulties in falling asleep). Conclusions: Considerable geographical variation can exist in the epidemiology of parental-reported SB in children. Cultural rules and standards could explain these findings.