Novel Validated Five-point Photonumeric Scales for Assessment of Static and Dynamic Forehead Lines

Area of Science:

• Dermatology
• Aesthetic Medicine
• Medical Imaging

Background:

• Forehead lines, both static and dynamic, are key indicators of facial aging.
• Objective assessment of forehead lines is crucial for treatment efficacy evaluation.
• Existing assessment tools may lack standardization across different settings and populations.

Purpose of the Study:

• To develop and validate novel five-point photonumeric scales for assessing static and dynamic forehead lines.
• To ensure the scales are applicable across diverse demographics and skin types.
• To establish the reliability of the scales in both digital and live validation settings.

Main Methods:

• Development of two five-point photonumeric scales: Croma Static Forehead Lines-Assessment Scale and Croma Dynamic Forehead Lines-Assessment Scale.
• Creation of a photoguide featuring diverse subjects (sex, age, Fitzpatrick skin types).
• Digital validation by 11 international raters and live validation by 4 raters.

Main Results:

• The Croma Static Forehead Lines-Assessment Scale achieved almost perfect inter-rater agreement (ICC 0.86 and 0.82) in digital settings.
• The Croma Dynamic Forehead Lines-Assessment Scale demonstrated almost perfect inter-rater agreement (ICC 0.83 and 0.80) digitally and substantial agreement live.
• Both scales showed excellent intra-rater agreement in digital and live assessments.

Conclusions:

• The Croma Static and Dynamic Forehead Lines-Assessment Scales exhibit excellent reliability.
• These validated scales are suitable for clinical and study use.
• The scales provide consistent forehead line assessment across ethnic groups, digitally and live.