Quantitative Analysis of the Human Face Skin Thickness-A High-Frequency Ultrasound Study

Understanding the topography of facial skin thickness is crucial in plastic surgery and underpins the success of numerous reconstructive, oncological, transplant, volumetric, and aesthetic procedures. Objective: This study aims to assess facial skin thickness using high-frequency ultrasound, evaluate its correlation with age, anatomical location, and physical parameters, and create a comprehensive facial skin thickness map. Methods: High-frequency ultrasound (75 MHz, axial resolution 21 μm) was used to scan 38 anatomical sites on the faces of 45 patients aged 22-73 years from esthetic medicine clinics. Measurements were performed manually within the device software. Extensive statistical analysis was conducted to determine dominant thickness values, assess variations by location and age, and evaluate correlations between biometric variables (age, weight, height, BMI) and skin thickness at various facial sites. Based on these findings, a relative thickness index and detailed topographic map of facial skin were developed. Results: The thickest skin was observed in the lower third of the nose, particularly at the nasal apex (median: 1907 μm, IQR: 455.75 μm, p < 0.001), while the thinnest skin was on the upper eyelid (median: 573.50 μm, IQR: 128.75 μm, p < 0.001). Skin thickness was significantly influenced by anatomical location (p < 0.001, η² = 0.52), age (p < 0.001, η² < 0.01), and their interaction (p < 0.001, η² = 0.04), collectively accounting for approximately 57% of variance in skin thickness. Correlations between biometric parameters and skin thickness were generally weak, though a few strong correlations were found between specific facial sites. Conclusions: A detailed facial skin thickness map, including a relative thickness index, was developed.