title: Perception of baldness and hair density.
abstract: BACKGROUND
  Androgenetic alopecia needs to be scored precisely.
  
  
  OBJECTIVE
  A possible measure is the ratio between the hair density in the parietal area and that in the occipital area which, being not affected by baldness, supposedly has a 'normal' density.
  
  
  METHODS
  On the vertex and just below the occipital protuberance of 109 men, two 1-cm(2) areas were identified. In both areas, hairs were clipped short and photographed by a videomicroscope. Hairs were then counted within a 30-mm(2)-wide central square section.
  
  
  RESULTS
  In the occipital area, the average count was 127/cm(2), without differences among the Hamilton/Norwood classes. In the parietal area, the average density significantly diminished from 138 to 47/cm(2). A main difference was found between classes 1-3 vertex and classes 4-6.
  
  
  CONCLUSIONS
  The parietal/occipital ratio decreased significantly only when baldness was clinically manifest. The parietal/occipital ratio cannot be a better measure of baldness severity than the rough Hamilton/Norwood scale. The perception of early baldness does not depend on the diminished hair density, but also on the progressive thinning of the hair shafts.
authors.affiliation: DiSEM, Section of Dermatology, University of Genoa, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Vecchio
authors.forename: M
authors.initials: M
authors.lastname: Guarrera
authors.forename: A
authors.initials: A
authors.lastname: Rebora
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000505:Alopecia / Q000145:classification* / Q000175:diagnosis; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012649:Self Concept; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index