Some general craniofacial features in Down's syndrome:
(1) At birth the face is round rather than oval, but over time it becomes more oval because maxillary growth is reduced compared to mandibular growth.
(2) The head shows brachycephaly.
(3) The ears have a reduced length.
(4) The nose shows a negative protrusion (subnasale to pronasale).
Cephalometric measurements:
(1) tragion to nasion (upper facial depth)
(2) superaurale to subaurale (vertical ear length)
(3) tragion to subnasale to tragion (maxillary arc)
The distances in a patient are converted to Z scores based on the age, race and gender.
In a patient with Down's syndrome, the Z score for each of these findings is often <= -2.0 and almost always are <= - 1.0.
