A micrograft is one or two hairs per graft. These are used in the combined follicular unit grafting surgical technique to define a subtle, "feathered" appearance to the scalpline and to any border of transplant with skin or in any low hair density situation. The one and two hair follicular unit grafts (i.e. the large percentage of them) are therefore micrografts. Micrografts that have been harvested from the donor from a cluster rather than from splitting a cluster apart are also follicular unit grafts. However, for example, if we split apart a three hair follicular unit to get a one or two hair micrograft, that micrograft would not be a follicular graft. The rare situation where one can intentionally make micrografts from splitting apart follicular units is the person with very strong, thick diameter hair whose thick diameter will not look as natural as quickly as when the diameter is compromised by cutting the follicle away from a tight cluster. Survival is compromised in this situation as well, however.
Courtesy: La Jolla Hair Restoration
A follicular unit micrograft is a follicular unit graft cut under a microscope which is state of the art. Mini/micrograft would simply be a minigraft being created under a microscope. Though use of the microscope here is appropriate, minigrafting is outdated.
Courtesy: Bill.