118 JOURNAL OF COSMETIC SCIENCE image, difficulties with lighting were avoided. The 3D images could easily be rotated with the software to provide the investigator with multiple views of the cellulite-affected skin. The subject's position on a rigid platform provided natural thigh compression. The roughness parameters Svm and Sdr were highly correlated with the expert image scores for ten standard images and were, therefore, designated as the quantitative mea­ sures of cellulite severity. The strength of the agreements (a) between expert image scores and roughness values and (b) between live visual scores and the roughness parameters strongly indicates that the 3D laser scanning and analysis methodology quantitatively characterizes cellulite. The na"ive judge and expert grades were highly correlated (r == 0.96) for the ten images, using the 0-9 scale. Svm and Sdr had the highest correlations to expert and na"ive scores (r 2: 0.86) (Figure 3). The strength of the correlations among na'ive grades, expert grades, and roughness measures confirms that the data quantita­ tively assesses human perception of cellulite and can, therefore, be used to guide devel­ opment and evaluation of treatment modalities. To our knowledge, this is the first report of a quantitative assessment of cellulite using 3D laser-scanning technology that also establishes the relationships between quantitative measurements of cellulite severity and human perception of the condition. A combination of biophysical techniques, including standardized, expert clinical grad­ ing of photographs (wrinkling, rhytids, laxity/tone, etc), roughness parameters (Ra, Rz) from replicas, and subject assessment of improvement, has been used successfully to evaluate treatments on photodamaged facial skin (37). Rao et al. (15) used a combination of high-quality digital photography (multiple angles, tangential lighting), expert image scoring (four trained dermatologists), and subject self-assessment in a paired-comparison design to evaluate cellulite treatments. Surface features were captured from shadows at various angles, but quantitative roughness values were not reported. Bertin et al. (6) concluded that a combination of techniques, including surface macrotexture, biome­ chanical properties, cutaneous flowmetry, and dermal/hypodermal structure determina­ tion, were effective in measuring the effect of treatments on cellulite. We found that cellulite severity, measured by expert image evaluation or quantitative surface roughness parameters, was significantly related to the body fat in the affected region, the architecture (surface area) of the dermal-subcutaneous border, and the tissue mechanical properties (compliance, stiffness). The body mass index and correlated an­ thropomorphic parameters (weight, thigh circumference) were highly associated with cellulite severity. The observed appearance of cellulite, i.e., cellulite severity as measured by surface roughness parameters, depended upon the percent fat in the thigh and the surface area of the dermal-subcutaneous junction. Cellulite severity was predicted by the percent fat in the subregion and the area of the dermal-subcutaneous border. While the biomechanical properties of energy absorption and stiffness correlated with surface roughness, they did not significantly add to the severity. The contributions of subcu­ taneous fat to cellulite were reported by Mole et al. (38). High-frequency ultrasound coupled with a patient questionnaire indicated that cellulite is caused by defects in adipocyte biology and the superficial fat tissues. Furthermore, the comparison of pa­ rameters for females and BMI- and age-matched males provided key information re­ garding the factors that influence cellulite. The outcomes suggest that percent thigh fat and surface area roughness deviation are the distinguishing features of cellulite, given the control for BMI and age in the comparisons. The identification of regional subcutaneous fat and the surface area of the dermal-subcutaneous border as the factors responsible for

QUANTITATIVE MODEL OF CELLULITE 119 the visual appearance of cellulite and the perception of severity will further guide the development of effective treatment modalities. ACKNOWLEDGMENTS This work was supported by grants from the Procter & Gamble Company and by USPHS GCRC grant #M0l RR 08084 from the National Center for Research Re­ sources, NIH. The authors wish to acknowledge Donna Buckley and Heidi Kalkwarf of the Cincinnati Children's Hospital GCRC, Jareen Meinzen-Derr of Cincinnati Chil­ dren's Hospital for statistical guidance, Christopher Laffley of Total Contact, Inc., and Patrick Stack of TrueGage for technical assistance. REFERENCES (1) B. M. Kinney, Discussion-Cellulite treatment: A myth or reality: A prospective randomized, con­ trolled trial of two therapies, endermologie and aminophylline cream, Plast. Reconstr. Surg., 104, 1115-1117 (1999). (2) Z. D. Draelos and K. D. Marenus, Cellulite: Etiology and purported treatment, Dermatol. Surg., 23, 1177-1181 (1997). (3) W. P. Smith, Cellulite treatments: Snake oils or skin science, Cosmet. Toiletr., 110, 61-70 (1995). (4) N. Collis, L.A. Elliot, C. Sharpe, and D. T. Sharpe, Cellulite treatment: A myth or reality: A prospective randomized, controlled trial of two therapies, endermologie and aminophylline cream, Plast. Reconstr. Surg., 104, 1110-1114 discussion 1115-1117 (1999). (5) R. M. DiSalvo, Controlling the appearance of cellulite, Cosmet. Toiletr., 110, 50-59 (1995). (6) C. Bertin, H. Zunino, J.C. Pitter, P. Beau, P. Pineau, M. Massonneau, C. Robert, and J. Hopkins. A double-blind evaluation of the activity of an anti-cellulite product containing retinol, caffeine, and ruscogenine by a combination of several non-invasive methods, J. Cosmet. Sci., 52, 199-210 (2001). (7) A. B. Rossi and A. L. Vergnanini, Cellulite: A review,]. Eur. Acad. Dermatol. Venereal., 14, 251-262 (2000). (8) G. W. Lucassen, W. L. N. van der Sluys, J. J. van Herk, A. M. Nuijs, P. E. Wierenga, A. 0. Barel, and R. Lambrecht, The effectiveness of massage treatment on cellulite as monitored by ultrasound imag­ ing, Skin Res. Technol., 3, 154-160 (1997). (9) F. Perin, C. Perrier, J. C. Pitter, P. Beau, S. Schnebert, and P. Perrier, Assessment of skin improvement treatment efficacy using the photograding of mechanically-accentuated macrorelief of thigh skin, Int. J. Cosmet. Sci., 22, 147-156 (2000). (10) W. Hu, E. C. Siegfried, and D. M. Siegel, Product-related emphasis of skin disease information online, Arch. Dermatol., 138, 775-780 (2002). (11) J. S. Artz and M. I. Dinner, Treatment of cellulite deformities of the thighs with topical aminophylline gel, Can. J. Plast. Sttrg., 3, 190-192 (1995). (12) D. M. Hexsel and R. Mazzuco, Subcision: A treatment for cellulite, Int.]. Dermatol., 39, 539-544 (2000). (13) A. Kligman, A. Fagnoni, and T. Stoudemayer, Topical retinol improves cellulite,]. Dermatol. Treat., 10, 119-125 (1999). (14) C. Pierard-Franchimont, G. E. Pierard, F. Henry, V. Vroome, and G. Cauwenbergh, A randomized, placebo-controlled trial of topical retinol in the treatment of cellulite, Am. J. Clin. Dermatol., 1, 369-374 (2000). (15) J. Rao, K. E. Paabo, and M. P. Goldman, A double-blinded randomized trial testing the tolerability and efficacy of a novel topical agent with and without occlusion for the treatment of cellulite: A study and review of the literature,]. Drugs Dermatol., 3, 417-425 (2004). (16) M. Lis-Balchin, Parallel placebo-controlled clinical study of a mixture of herbs sold as a remedy for cellulite, Phytotherapy Res., 13, 627-629 (1999). (17) M. Rosenbaum, V. Prieto, J. Hellmer, M. Boschmann, J. Krueger, R. L. Leibel, and A.G. Ship, An