Forensic facial reconstruction may be the final option available to draw public attention in cases where the identity of an individual cannot be established by standard identification methods. Two fundamental components of all forensic facial reconstruction techniques are cranial morphology and soft tissue depth databases. The purpose of this study was to extend such databases by providing a complete set of accurate facial soft tissue thickness measurements, acquired from a contemporary adult population from Germany. The material for the study consisted of 320 (160 male, 160 female) anonymised multi-slice computerised tomography (MSCT) scans of individuals drawn from a German population. In Amira®, 3D models of the surfaces of the skull and the facial skin were semi-automatically segmented using calculated thresholds and surface extraction algorithms. Facial soft tissue depth was measured at 10 midline and 28 bilateral anatomical landmarks. The analysis of facial soft tissue thickness versus BMI, sex and age indicated that, at a number of the landmarks, facial soft tissue depth is significantly (p < 0.05) influenced by all three biometric variables. Facial soft tissue thickness increased with increasing BMI. The differences between males and females were statistically significant (p < 0.05) for almost all anatomical landmarks with the exception of a few in the region of the nasal root and orbitals. Asymmetry was noted at over half of the bilateral landmarks. The differences between the results from this sample and those obtained from comparable databases contradict the hypothesis that population specificity significantly influences facial soft tissue thickness.
Keywords: Amira; Computed tomography (CT); Facial soft tissue depth; Forensic facial reconstruction; Half-maximum-height (HMH); Human identification.