||The majority of patients with Down's syndrome exhibit some abnormality of the external ear. The ear is often small and low-set, with a deformed helix. The ear is considered to be low-set when the helix meets the cranium below a line between the outer canthus of the eye and the occipital protuberance (the "Frankfort plane"). When the head is level, the entrance to the external auditory canal should normally be at approximately the same level as the ala nasi.
In this patient with Down's syndrome the external auricle is smaller than normal, low-set, and displays an incompletely developed superior helix.