BACKGROUND AND OBJECTIVE: Oral habits are risk factors for the incidence of malocclusion in deciduous teeth. Investigating the factors associated with malocclusion is essential for the policies of public health. The present study was conducted to determine the prevalence of malocclusion and oral habits in children aged 3 – 5 years old in kindergartens of Ramsar, Iran.
METHODS: In this cross-sectional study, 180 children with complete primary dentition and without previous orthodontic treatment were randomly examined in kindergartens of Ramsar. After filling out questionnaires about the oral health of the child by the parents, the intraoral examination was performed using mirror, catheter and periodontal probe in terms of occlusion. 
FINDINGS: Malocclusion was observed in 138 children (76.7%), while 80 children (44.4%) had oral habits. There was no significant relationship between total habits and malocclusion. Children with bruxism had a higher incidence of edge to edge overjet, and overbite. There was a significant relationship between bruxism and the condition of overjet and overbite (p < 0.0001). Of 54 children with bruxism, abnormal overjet in 31.5% of them was edge to edge, in 20.4% of them was increased and in 1.9% of them was reverse, and abnormal overbite in 35.2% of them was edge to edge and in 27.8% of them was deep. There was a significant relationship between finger-sucking habit and open bite dental occlusion (p < 0.004) and of 16 children with finger-sucking habit, 37.5% were open bite.      
CONCLUSION: The results of this study showed that there is no relationship between total oral habits and malocclusion in children.