3D stereophotogrammetry versus traditional craniofacial anthropometry: Comparing measurements from the 3D facial norms database to Farkas's North American norms.

INTRODUCTION: Datasets of soft-tissue craniofacial anthropometric norms collected with the use of different methods are available, but there is little understanding of how the measurements compare. Here we compare a set of standard facial measurements between 2 large datasets: the 3D Facial Norms (3DFN) dataset collected with the use of 3D stereophotogrammetry (n = 2454), and the Farkas craniofacial norms collected with the use of direct anthropometry (n = 2326).
METHODS: A common set of 24 craniofacial linear distances were compared by computing standardized effect sizes (Cohen d) for each measurement to describe the overall direction and magnitude of the difference between the 2 datasets.
RESULTS: Variables with higher mean d values (suggesting greater discrepancy across datasets) included measurements involving the ear landmark tragion, the landmark nasion, the width of nasolabial structures, the vermilion portion of the lips, and palpebral fissure length. Variables with lower mean d values included smaller midline measurements involving the lips and lower face and horizontal distance measures between the eyes. Eight measurements showed a significant negative correlation (P < 0.05) between Cohen d and age, indicating greater similarity across the 2 datasets as age increased.
CONCLUSIONS: There are considerable differences between the 3DFN and Farkas norms. In addition to the measurement methods, other factors accounting for discrepancies may include secular trends in craniofacial morphology or differences in ethnic composition.