Morphometric analysis and classification of the facial phenotype associated with fetal alcohol syndrome in 5‐ and 12‐year‐old children

Abstract

Landmark-based morphometric analysis holds promise for quantitative assessment of craniofacial dysmorphology. We describe an application of facial shape analysis to characterize the facial anomalies associated with fetal alcohol syndrome (FAS) in a mixed ancestry population. Generalized Procrustes analysis, regression and discriminant function analysis were applied to stereo-photogrammetrically derived 3D coordinates of landmarks taken from 34 subjects (n = 17 FAS and n = 17 normal controls). Four shape analyses were carried out, namely a comparison of the FAS and control facial shapes at age 5, and one at age 12; a comparison of the FAS facial shapes at ages 5 and 12; and a comparison of control facial shapes at ages 5 and 12. The first two analyses showed that the FAS face is characterized by small palpebral fissures, a thin upper lip, and midfacial hypoplasia. Classification of subjects as having FAS using leave-one-out cross-validation showed that the 5-year-old group could be classified with 95.46% accuracy and the 12-year-olds with 80.13% accuracy. The third and fourth analyses revealed that the differences in facial shape between FAS individuals in different age groups were more pronounced than for control individuals, supporting the notion that FAS facial anomalies diminish with age. Geometric morphometric analysis of stereo-photogrammetrically derived 3D facial landmarks allows visualization of the facial anomalies associated with FAS, as well as classification of facial shapes.