Relationship between the echogenicity of subcutaneous tissue and the depth of forehead wrinkles

Background/purpose: Subcutaneous tissue is rarely studied in research on wrinkles. We used diagnostic ultrasonography to produce images of subcutaneous tissue of the forehead, one of the areas where age‐related wrinkles form. We quantified the resulting echogenicity and investigated its relationship with wrinkle depth. Methods: One hundred and seventy‐three Japanese subjects were divided into four age groups (21–28 years, 35–41 years, 47–59 years, 65–75 years). Maximum wrinkle depth (R_max) was measured in the forehead. On an ultrasound image, which was captured by scanning perpendicular to the deepest wrinkle, we set a 12.5‐mm‐wide region of interest by aligning the deepest point of the wrinkle at its center and then obtained the ratio of the area exceeding this threshold to the total area as the echogenicity. Results: R _max increased and the echogenicity decreased with age. A negative correlation was found in the oldest group but was not found in other groups, presumably due to individual differences in the echogenicity among younger subjects. Conclusion: This study suggests that the internal structure of subcutaneous tissue, as observed by ultrasonography, is related to wrinkle depth. The relationship between wrinkle depth and echogenicity of subcutaneous tissue is particularly pronounced in the elderly.