ABSTRACT
THE FOLLICULAR UNIT The advent of follicular unit transplantation is credited to Bob Limmer in San Antonio, who, in the late 1980s, began using microscopes for creation of small one-to five-hair grafts inserted into needle slits. Limmer removed all excess non-hair-bearing tissue, which allowed for the natural hair groupings to be transplanted into 18-gauge needle sites. While improvements are still being made, most follicular unit transplants today are quite similar to Limmer’s original technique. Around 1995, William Rassman documented the natural growth patterns of hair as seen through a hair densitometer. He stated that, ‘‘hairs grow in groups, most frequently in pairs, sometimes in groups of three, and more rarely in groups of four and five; understanding this architecture is critical, the incorporation of the patient’s growing hair groups is to be exploited in the design of the restoration.’’ In 1997, Robert Bernstein and Bill Rassman described their technique under the moniker ‘‘follicular unit transplantation,’’ thus contributing the term ‘‘follicular unit’’ to the nomenclature.
