title: The mathematics of hair restoration surgery.
abstract: BACKGROUND
  Mathematics is prevalent in almost all aspects of life, and so it is with hair restoration surgery. This article explores some of the mathematical relationships that exist in this quickly growing subspecialty of cosmetic surgery.
  
  
  OBJECTIVE
  The objective of this article is to demonstrate a few of the mathematical correlations that are present in hair restoration surgery.
  
  
  METHODS
  Several subdivisions of this subspecialty are analyzed from a mathematical perspective.
  
  
  RESULTS
  Mathematics pervades many of the aspects of hair restoration, from the donor site, to the recipient site, to scalp reduction, to scalp extension, and the list goes on.
  
  
  CONCLUSIONS
  To be able to perform hair restoration surgery in a very precise and accurate way, one should have a good grasp of the mathematical relationships that exist in this field.
authors.affiliation: Department of Dermatology, University of Pittsburgh Medical Center, Pennsylvania, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Brandy
mesh_terms: D006197:Hair / Q000637:transplantation*; D006801:Humans; D008433:Mathematics; D012535:Scalp / Q000601:surgery; D013518:Surgery, Plastic / Q000379:methods*; D014019:Tissue Donors