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Updated: Jun 24, 2026
06:41
A New Technique for Quantitative Analysis of Hair Loss in Mice Using Grayscale Analysis
Published on: March 9, 2015
Perception of baldness and hair density
F Vecchio1, M Guarrera, A Rebora
1DiSEM, Section of Dermatology, University of Genoa, Italy.
Dermatology (Basel, Switzerland)
|February 9, 2002
Summary
The parietal/occipital hair density ratio is not a superior measure for assessing androgenetic alopecia severity compared to the Hamilton/Norwood scale. Early baldness perception involves hair shaft thinning, not just density reduction.
Area of Science:
- Dermatology
- Trichology
Background:
- Accurate assessment of androgenetic alopecia (male-pattern baldness) is crucial.
- Existing scoring systems require precise and objective measures.
Purpose of the Study:
- To evaluate the efficacy of the parietal/occipital hair density ratio as a measure of androgenetic alopecia severity.
- To compare this ratio with the established Hamilton/Norwood scale.
Main Methods:
- Studied 109 men, measuring hair density in 1-cm² areas on the vertex and occipital scalp.
- Utilized videomicroscopy to count hairs within a standardized 30-mm² central section.
- Calculated the ratio of hair density between the parietal and occipital areas.
Main Results:
- Occipital hair density averaged 127 hairs/cm² across all Hamilton/Norwood classes.
- Parietal hair density significantly decreased from 138 to 47 hairs/cm² in later stages.
- The parietal/occipital ratio showed a significant decrease only in clinically apparent baldness stages (Hamilton/Norwood classes 4-6).
Conclusions:
- The parietal/occipital hair density ratio is not a more effective measure of baldness severity than the Hamilton/Norwood scale.
- Early perceptions of baldness are influenced by hair shaft thinning, not solely by reduced hair density.
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