title: Asymmetry of the Receding Hairline in Men With Early Androgenetic Alopecia.
abstract: BACKGROUND
  The Norwood classification system is commonly used to ascertain the progress of androgenetic alopecia (AGA) with a robust and quick assessment, but it lacks precision in the frontal region, notably during the onset of male pattern hair loss.
  
  
  OBJECTIVE
  Due to the ongoing technical improvement in restorative hair transplantation practices, we aim to develop simple quantitative methods for measuring the progression of AGA.
  
  
  METHODS
  Here, we used a quantitative system to evaluate the progress of AGA of the frontal receding hairline in a case study with 41 patients.
  
  
  RESULTS
  We found subtle differences in the extent of frontotemporal regressions that were not captured by the Norwood classification system. The majority of patients exhibited significantly larger right-sided frontotemporal regressions.
  
  
  CONCLUSIONS
  These results indicate that the quantification system used is a valuable tool in complementing the Norwood classification system to more precisely determine the recessing hairline characteristics in early stages of hair loss. Our findings also suggest that hairline regression in AGA-affected patients is asymmetrical, a hitherto unnoticed disorder-associated phenomenon with unknown biological causality.
authors.affiliation: Centre for Modern Hair Transplantation, Berlin, Germany info@ifue-haartransplantation.de.
authors.forename: Reza Pashmineh
authors.initials: RP
authors.lastname: Azar
authors.affiliation: Department of Biotechnology, Technische Universität Berlin, Berlin, Germany.
authors.forename: Alexander Horst
authors.initials: AH
authors.lastname: Thomas
authors.affiliation: Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Maurer
authors.affiliation: Department of Dermatology and Allergy, Charité-Universitätsmedizin Berlin, Berlin, Germany.|Department of Biotechnology, Technische Universität Berlin, Berlin, Germany.|provio GmbH, Biomedical Research and Innovation, Berlin, Germany.
authors.forename: Gerd
authors.initials: G
authors.lastname: Lindner
mesh_terms: D000328:Adult; D000505:Alopecia / Q000145:classification*; D018450:Disease Progression; D006197:Hair; D006801:Humans; D008297:Male; D008875:Middle Aged; D012535:Scalp
keywords: Norwood classification; androgenetic alopecia; follicular unit extraction; hair follicle; hair transplantation