Influence of sex and body mass index on facial soft tissue thickness measurements of the northern Chinese adult population

Forensic facial reconstruction is a mixture of science and art, as it attempts to reestablish the contours of the soft tissues over the skull. From a forensic point of view, identification of an unknown body relies heavily on this visual aspect of recognition. To obtain acceptable results in forensic facial reconstruction, accurate facial soft tissue thickness data are essential. Until now, despite numerous works related to soft tissue thickness, there is little information in this area for the Chinese population. To this end, this study developed soft tissue thickness data for the Chinese adult population. Spiral computed tomography (CT) data and the body mass index (BMI) of 200 northern Chinese aged 18-32 years were collected. Soft tissue thickness measurements at 20 anthropological landmarks on the skull were taken, based on the three-dimensional models of the skull and face reconstructed from the spiral CT data of each subject. Considering the sex and BMI of the individuals, general descriptive analyses of soft tissue thickness were determined. Statistical analyses were performed between males and females in each BMI group, as well as between each of the BMI categories for males and females, respectively. The results revealed that males have thicker soft tissues than females at most of the anthropological landmarks in the Chinese population, similar to other populations. However, only one-third of these differences were statistically significant between males and females. Taking into consideration the nutritional status, the soft tissue thickness measurements increased with increased BMI levels for both sexes at each landmark, and the statistically significant differences were depicted between the different BMI categories at most of the landmarks. In conclusion, this study has provided useful reference points of the adult northern Chinese population for forensic facial reconstruction, and recommends that the nutritional status of the subject be considered during skull reconstruction procedures.