Statistical analysis
Raw data concerning water content, elasticity, and sebum were analyzed by a multiway repeated measures ANCOVA (GLM procedure, SAS ver. 9.2). The treatment type (SINGLE or TRIPLE) was considered as a fixed effect, the time effect (before/after treatment) was treated as the repeated measure, while the number of support treatments and the age of the women were taken into account as a covariate. ANCOVA results are expressed as mean ± standard error of mean (SEM).