The use of non-invasive instruments in characterizing human facial and abdominal skin.

Background And Objective: The skin is highly variable. This variation, although helpful for function, causes inconsistencies when assessed using subjective scales. The purpose of this study is to measure differences in skin on the face and abdomen using non-invasive, objective devices as a method to eliminate subjective error and help reduce intra- and inter-observer variability in clinical analysis.

Study Design/materials And Methods: Eighty-eight subjects between the ages of 18 and 61 were enrolled in this study. These subjects varied in age, ethnicity, and Fitzpatrick score. Facial analysis was performed by clinical evaluation and utilizing non-invasive objective devices which included the DermaScan C 20 MHz HFUS (Cyberderm, Broomall, PA), Tru Vu (Johnson and Johnson), BTC 2000 (SRLI Technologies, Nashville, TN), Derma Unit SSC3 (CK Electronic, Köln, Germany), and the Chromometer.

Results: Non-invasive devices were shown to be consistent and accurate through repeated measurement at each of the anatomical points with error rates of less than 5%. Chromometer measurements were able to categorize patients into Fitzpatrick level. DermaScan measurements demonstrated decreasing skin thicknesses associated with increasing age, smoking, and female gender. Derma Unit SSC 3 showed gender and sun exposure related differences in sebum concentration, pH, and moisture content. The Derma Unit SSC 3 sebum concentration also showed correlation with Tru Vu readings for clogged pores and bacterial activity.

Conclusion: The skin assessment scales that are in use today are often prone to variability and inaccuracy due to their subjectivity. Use of the described objective non-invasive facial analysis method provides an accurate, objective analysis of human skin which can be used to measure changes pre- and post-operatively, or even screen patients prior to procedure to identify non-responders or those prone to adverse events. Utilization of these devices introduces a foundation on which a strong evidence-based approach to aesthetic medicine can be built.