title: Progression of surgical hair restoration techniques.
abstract: BACKGROUND
  Early surgical hair restoration (SHR) techniques were fraught with limitations. Major advancements and refinements have taken place yielding minimally invasive, relatively scar-free, and natural-looking hair transplantations.
  
  
  OBJECTIVE
  Our aim was to review the origins and advancements of SHR and to discuss future directions for the field.
  
  
  METHODS
  Searches were performed using: Pubmed, Scopus, and the International Society of Hair Restoration Surgery's Hair Transplant Forum International for articles related to SHR. Reference sections of articles obtained were reviewed. Relevant textbooks obtained were reviewed.
  
  
  CONCLUSIONS
  SHR techniques originated as macro-level graft transplantations and excision of scalp tissue. They progressed toward micro-level graft transplantations performed with extreme caution and precision. However, all SHR techniques are limited by their reliance on existing donor hair to fill balding areas. Further advancements in hair follicle cell cloning and regeneration of growth may offer a solution to this overarching limitation.
authors.affiliation: Department of Medicine, University of Toronto, Toronto, ON, and Mediprobe Research Inc., London, ON agupta@execulink.com.
authors.forename: Aditya K
authors.initials: AK
authors.lastname: Gupta
authors.affiliation: Department of Medicine, University of Toronto, Toronto, ON, and Mediprobe Research Inc., London, ON.
authors.forename: Danika C A
authors.initials: DC
authors.lastname: Lyons
authors.affiliation: Department of Medicine, University of Toronto, Toronto, ON, and Mediprobe Research Inc., London, ON.
authors.forename: Deanne
authors.initials: D
authors.lastname: Daigle
mesh_terms: D000505:Alopecia / Q000601:surgery*; D005260:Female; D018859:Hair Follicle / Q000637:transplantation*; D049672:History, 19th Century; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D008297:Male; D013518:Surgery, Plastic / Q000266:history / Q000379:methods* / Q000639:trends