Appendix A.

Questionnaire sent to the parents and guardians of study participants

Family sociodemographic characteristics	Response optionsa
Child’s sex	Female
	Male
Child’s age (year)	[open]
What is the father’s education level?	Under diploma
	Diploma
	Associate/bachelor’s degree
	Higher academic degrees
What is the mother’s education level?	Under diploma
	Diploma
	Associate/bachelor’s degree
	Higher academic degrees
What is the mother’s job?	Medical services
	Employee
	Private
	Housewife
What is the father’s job?	Medical services
	Employee
	Private
	Unemployed
Does your child live in the same house with both parents?	No
	Yes
What is the family’s income level (Rial)?	<50 million
	50 to 100 million
	100 to150 million
	150 to 200 million
	≥200 million
How many children do you have in your family?	[open]
What is the child’s birth rank in the family?	[open]
Oral health behaviours of children	Response optionsa
How many times does your child brush his/her teeth per day?	Once a day
	Two or more times a day
	Less than once a day
Does your child use fluoride toothpaste when brushing his/her teeth?	No
	Yes
Does your child use dental floss daily?	No
	Yes
Did your child have a regular dental appointment in the last 12 months?	No
	Yes
Consumption of cariogenic foods and drinks	Response optionsa
How many times does your child eat cariogenic foods? (including sugary and/or chewy foods such as chocolates, candies, candy bars, pastries, chips, snacks…)	Never
	Once a day
	Twice a day
	Thrice a day or more
How many times does your child eat cariogenic drinks? (including any sugary beverage such as non-diet soft drinks, lemonade, sports drinks, juices, fruit extracts, fruit leather, sweetened coffee or tea…)	Never
	Once a day
	Twice a day
	Thrice a day or more

^aThe response options were not necessarily the same as those used for the statistical analysis. Due to small frequencies, some responses were aggregated (see Table 3)