Early childhood is a pivotal period for establishing lifelong oral hygiene habits. Despite its preventable nature, dental caries remains one of the most common chronic conditions affecting children worldwide, with significant consequences for physical health, social development, and educational attainment. In Iran, national surveys indicate a high burden of dental disease among preschoolers, with a mean Decayed, Missing, and Filled Teeth (DMFT) score of 5.84 in 5–6-year-olds and over 88% of children showing clinical signs of caries. The development of oral health behaviors in children aged 4–6 is influenced by both physiological limitations and behavioral factors. At this age, children are gaining motor independence but lack the skills and consistency needed for effective oral hygiene. Parents and caregivers therefore play a critical role in establishing, supervising, and reinforcing toothbrushing routines. Variations in parental knowledge, motivation, and capacity can strongly impact children’s oral health outcomes. Targeted interventions that address these factors are essential for improving oral hygiene practices in preschool populations and reducing the prevalence of early childhood dental caries.