Layer-specific facial soft-tissue thickness in 1174 Chinese adults: Implications for finite-element headforms and ergonomic design

Accurate representation of facial soft‑tissue thickness (FSTT) is indispensable for finite‑element (FE) head models used in ergonomics, forensic reconstruction and biomedical simulation. This study quantifies layer‑specific FSTT in 1174 Chinese adults (18-90 years) using multislice computed tomography. Soft‑tissue thickness was measured at 33 craniofacial landmarks and partitioned into CT-derived composite compartments corresponding to skin, fat and muscle. Landmarks were aggregated into 17 anatomical regions for region‑based modelling. Multivariate analysis of variance (MANOVA) revealed that total FSTT and the fat- and muscle-associated compartments were significantly influenced by sex and age (p < 0.001), whereas skin-related thickness was primarily age‑dependent. Regional mean values were assigned to a Chinese P50 reference headform, yielding a multi‑layer, region‑specific FE mesh that supports simulation of facial contact scenarios. The resulting database provides population- and layer-resolved modelling inputs for anatomically informed ergonomic simulations and virtual cohort testing of head-worn products accommodation.