The impact of co-sleeping less than 6 months on children's anxiety, oral habits, and malocclusion in a Spanish sample between 2 and 5 years old: a cross-sectional study

Objectives Families often use co-sleeping to mitigate potential physiological and emotional effects on infants. The purpose of this study was to investigate whether the early termination of co-sleeping is associated with high levels of anxiety, non-nutritive sucking habits for self-comfort, and increased malocclusion. Methods A cross-sectional study was performed on the parents of 215 children [aged 2-5 years (3.94 +/- 0.89)], who were divided according to the duration of co-sleeping (<= 6 months or >6 months). The parents completed a questionnaire about co-sleeping, sucking, breastfeeding habits, and anxiety. Finally, a clinical examination was carried out to diagnose malocclusion according to the World Health Organization (WHO) index, and the aesthetic component of the Index of Orthodontic Treatment Need (IOTN-AC) was recorded. Results Children that co-slept for 6 months or less had an increased incidence of pacifier use (P < 0.05), finger sucking (P < 0.01), and atypical swallowing (P < 0.05). Lower anxiety levels were found in the group with a longer duration of co-sleeping (P < 0.01). In the assessment of malocclusions, the group that co-slept for <= 6 months had higher IOTN scores (P < 0.01) and WHO indices (P < 0.05); in addition, there were differences in anterior open bite (P < 0.05), posterior crossbite (P < 0.01), skeletal Class II (P < 0.01), canine Class II (P < 0.05), and overjet (P < 0.05). Conclusion A co-sleeping duration of >6 months appears to be a protective factor associated with less anxiety, fewer negative sucking habits, and a decreased incidence of malocclusions in co-sleeping children.