J. H. Baek

Comparison between ultrasonography (Dermascan C version 3) and transparency profilometry (Skin Visiometer SV600)

Background/purpose: A recently developed method to estimate skin smoothness is the replica method, which may have the limitation of the roughness difference of actual skin due to the skin‐replicating process. Therefore, observation of dermal layer change is very important. For this purpose, ultrasonic display equipment is generally used. The purpose of the present study was to investigate the correlation between skin roughness and dermal density in wrinkle evaluation.

Retinyl retinoate, a novel hybrid vitamin derivative, improves photoaged skin: A double-blind, randomized-controlled trial

Background: All‐trans‐retinoic acid (RA) and all‐trans‐retinol (ROL) are not widely used as anti‐wrinkle agents due to their irritancy and photo‐stability, respectively. Therefore, the safety and photo‐stability in the development of RA or ROL derivatives have been an important issue.

Analysis of the temporal change in biophysical parameters after fractional laser treatments using reflectance confocal microscopy.

Fractional photothermolysis is a popular treatment option for photorejuvenation. Previous literature studies have demonstrated the clinical effectiveness of fractional photothermolysis on cutaneous photoaging; however, the associated changes in biophysical properties of the skin following fractional photothermolysis have not been fully elucidated. This study was conducted to investigate the temporal changes in biophysical parameters after fractional laser treatment on Asian skin.

Relationship between clinical features of facial dry skin and biophysical parameters in Asians

There have been few reports classifying the biophysical characteristics of Korean women with healthy skin. Consequently, the aim of this study was to find the most useful parameters for categorizing skin types based on a clinical assessment. One hundred and three female volunteers, aged 20–59, participated in this study. We conducted a self‐evaluation questionnaire, a clinical assessment of the facial skin, and non‐invasive measurements on the cheek under controlled environmental conditions. The questionnaire survey indicated that 72% of respondents had dry skin. However, results of the clinical assessment focusing on skin roughness and scaling of the cheek showed that 6 subjects had very dry skin (6%), 29 had dry skin (28%) and 68 had normal skin with sufficient moisture (66%). We analysed the correlation between the clinical assessment and biophysical parameters. As a result, we obtained six biophysical parameters that had relatively higher correlations with clinical assessment than other parameters. Our study provided general information about the physiological characteristics of normal skin in Korean women and suggested useful parameters for characterizing dry skin.

Facial skin physiology recovery kinetics during 180 min post-washing with a cleanser

Facial cleansing is important to clean and exfoliate the skin while maintaining optimal physiologic function. However, there is insufficient data on the very early stage of skin change after applying soap or cleansing foam. We investigated the recovery kinetics of facial skin physiology during 180 min after exposure to the cleanser.

Dermal matrix affects translucency of incident light on the skin.

The age‐dependent changes in the optical reflection characteristics have been studied about skin hydration, melanin index, or skin color. However, the age‐dependent changes in the optical reflection have little attention on inner skin structures. To control the factors affecting the optical reflection except for dermal matrix, subjects were selected as our guideline and we evaluated the optical reflection of subsurface on skin layers of two age groups.

Twelve-point scale grading system of scanning electron microscopic examination to investigate subtle changes in damaged hair surface.

To assess the hair surface condition, scanning electron microscope (SEM) is commonly used and it remains an indispensable hair morphology characterization technique. Yet, the technique is criticized for having subjective viewpoints and limitations in distinguishing the appearance of cuticle layers.

The quantitative analysis of spreadability, coverage, and adhesion effect after application of the base make-up product

It is needed to evaluate the spreadability, coverage, and adhesion of facial base makeup products.

Analysis of comedone, sebum and porphyrin on the face and body for comedogenicity assay

Many ingredients used in cosmetics evoke a comedogenic response. Rabbit ear model (REM) is a useful method that can replace human in examining materials and products in early developmental stage. However, a number of studies pointed out its disadvantage that it overreacts to comedogenic materials. The purpose of this study was to find the most appropriate region for evaluating comedogenicity in human skin.

The effect of physically applied alpha hydroxyl acids on the skin pore and comedone

Alpha hydroxy acids (AHA) have been recognized as commonly used therapy for acne. Our studies examined whether an additional effect of physical treatment using chemical peeling combined with negative pressure and compared with AHA treatment only occurs in acne‐prone subjects.