Anthropometric craniofacial pattern profiles in Down syndrome.

A series of 21 anthropometric craniofacial measurements was performed on 199 individuals with Down syndrome (DS), age 6 months to 61 years. These were compared to age and sex-matched normal standards, and Z score pattern profiles were constructed. These profiles confirmed brachycephaly and reduced ear length. With increasing age, maxillary growth was reduced in comparison to mandibular growth. Clinically, this was manifested by a change in facial shape from the characteristic round face of infancy to an oval shape in later life. Stepwise forward discriminant function analysis identified a subset of three variables (ear length, maxillary arc, and upper facial depth) which could accurately classify greater than 99% of the individuals in the combined sample of affected and unaffected individuals. Of the subjects with DS, 96.8% were classified correctly. These findings demonstrate the usefulness of anthropometric craniofacial pattern profiles in defining abnormal facial dimensions in particular syndromes and documenting the changes that occur with age. The technique should facilitate syndrome recognition, identification of carriers, and comparisons between syndromes.