3D Analysis of Philtrum Depth in Children with Fetal Alcohol Syndrome

Diagnosis of fetal alcohol spectrum disorder (FASD) is complex and difficult. The estimated number of unreported FASD is thus assumed to be substantial. In our cross-sectional study, we aimed to identify possible metric differences in philtrum depth in children with fetal alcohol syndrome (FAS) compared to healthy controls based on non-invasive 3D facial scanning in order to provide an objective, metrical tool improving FASD diagnosis.

Twenty-five children with confirmed FAS and 30 healthy school children without FAS, both in the mixed dentition, were prospectively recruited and 3D facial scans were performed after recording body length, weight and head circumference. Philtrum surface data were extracted and metric philtrum depth was determined at four geometrically defined measuring points (P1-P4) along the vertical length of the philtrum.

Philtrum depths at P1 (P = 0.025), P2 (P = 0.001), P3 (P < 0.001) and P4 (P = 0.001) as well as mean philtrum depth P1-P4 (P < 0.001) differed significantly between patients with and without FAS. Compared to controls, the philtrum was shallower in patients with FAS by on average 0.4 mm at each of the respective points. Whereas no differences could be determined for body height and weight, head circumference was significantly smaller in patients with FAS (P = 0.001), particularly in girls (P = 0.008).

Apart from head circumference, philtrum depth is significantly reduced in children with FAS and can thus be used as diagnostic indicator to aid and confirm FAS diagnosis. In contrast to visual assessments, 3D face scan methods allow a more objective quantification and can thus provide additional evidence in FAS diagnosis.