Early Intervention for Children With Cleft Palate: First Report on the Wechsler Preschool and Primary Scale of Intelligence at Age Four

In recent years, the necessity of early intervention in speech therapy for children with cleft palate has become widely recognized. To achieve more effective treatment outcomes through comprehensive early intervention, we launched an Early Intervention Program (EI Program) in 2010 at the Department of Speech and Orofacial Function Development, Aichi Gakuin University Dental Hospital. As part of a series of studies to evaluate the effectiveness of the EI Program, the present study aimed to examine the relationship between participation in the EI Program and cognitive development in children with cleft palate. A total of 33 children who underwent palatoplasty and participated in the EI Program (EI group) and 40 children who did not participate (control group) at the Cleft Lip and Palate Center were included. The Wechsler Preschool and Primary Scale of Intelligence (WPPSI) was administered at age four to assess full-scale IQ, verbal IQ, and performance IQ. Results showed that, overall, children with cleft palate exhibited higher performance IQ but slightly lower verbal IQ compared to population norms. Moreover, the EI group demonstrated significantly higher full-scale IQ and verbal IQ compared to the control group. Given that verbal IQ reflects crystallized intelligence developed through learning and experience, these findings suggest that early speech intervention may contribute to promoting crystallized intelligence development in children with cleft palate.