Impaired oral-motor function in children with Down's syndrome: a study of three twin pairs.

Three twin births occurring within 18 months in Oxfordshire, in which a girl with Down's syndrome was twin to an unaffected boy, provided an opportunity for a closely matched comparison of ratings on the Schedule for Oral Motor Assessment, which examines oral-motor function in a systematic and reliable way. A detailed description of the video-recording of one twin pair is included. This illustrates abnormalities of oral-motor function which may occur generally in Down's syndrome, as suggested further by a numerical tabulation of the differences found between the twins.