Characteristics of orofacial function and sleep disorders in children with signs of autism spectrum disorder: A cross-sectional study

BACKGROUND: Children with autism spectrum disorder (ASD) have higher rates of feeding problems and sleep disorders. Research on feeding problems in children with ASD has focused on behavioral, psychological and nutritional aspects. However, the biomechanics underlying these issues remains unknown. OBJECTIVES: The present study aimed to evaluate the relationship between signs of ASD, orofacial function and sleep disorders in children. MATERIAL AND METHODS: A total of 56 Japanese early elementary school children aged 6-9 years were recruited. The subjects underwent physical examinations, intraoral inspections and orofacial functional assessments. The parents or legal guardians of the children completed questionnaires regarding the subjects' dietary and meal habits, the Social Responsiveness Scale, Second Edition (SRS-2), and the Japanese Sleep Questionnaire for Elementary Schoolers (JSQ-ES). Each assessment item was compared between 2 groups divided according to the SRS-2 scores, and the relationships with psychological traits were investigated using Spearman's rank correlation coefficient. RESULTS: Thirteen of the 56 children had SRS-2 T scores ≥60, indicating possible ASD. Masticatory performance was significantly lower in the high SRS-2 group than in the low SRS-2 group (p < 0.05). Additionally, the high SRS-2 group showed significantly higher T scores on the JSQ-ES for insomnia (p < 0.05) and excessive daytime sleepiness (p < 0.01). Occlusal force (p < 0.05), masticatory performance (p < 0.05), insomnia (p < 0.001), and excessive daytime sleepiness (p < 0.001) were significantly correlated with the SRS-2 score. CONCLUSIONS: These results suggest that low masticatory performance contributes to feeding problems in children with signs of ASD. Additionally, the severity of ASD symptoms is associated with the severity of orofacial functional and feeding problems, as well as sleep disorders.