Relationship between physical parameters and blood flow in human facial skin.

We evaluated the association between the cutaneous blood flow and the three-dimensional morphology of the skin by measuring various aspects of blood flow (resting blood flow, mean blood flow during cooling, minimum blood flow during cooling, mean blood flow after cooling, and maximum blood flow after cooling) of the cheeks and foreheads of 40 healthy women (aged 60-77 years). We also analyzed the three-dimensional morphology of the skin surface (sWa, sWp, sWt, sWq) in replicas obtained from foreheads, cheeks, and other sites on the faces of those subjects. In addition, we measured the skin elasticity and water content of the stratum corneum on the cheeks of those women. No correlation was observed between the parameters of the blood flow and the surface morphology of the forehead. On the cheek, however, significant negative correlations were observed between those parameters. Among the blood flow parameters, the resting blood flow and the mean blood flow during cooling showed particularly high correlations. Concerning the surface morphology parameters, high correlations were observed in parameters related to local changes such as sWp and sWt. None of the cutaneous properties examined (including the skin elasticity and water content of the stratum corneum) correlated with the blood flow or the surface morphology parameters of the cheek. Facial wrinkles are classified into linear grooves, which develop at the corner of the eye and on the forehead, and glyphic wrinkles, which develop as deep grooves in areas such as the cheek. These results suggest that a reduction in blood flow is one of the putative causes of local irregularities observed in the cheek, that is, the glyphic wrinkles, of elderly women.