The medical term for hair loss. There are numerous types of alopecia. Alopecia can be classified as diffused or localized, and by presence or absence of scarring. The most common form of surgically treatable alopecia is androgenic alopecia (AGA).
An average number of hairs in each follicular unit. It is determined by dividing the number of hairs present in 1cm2 by the number of follicular units observed in the same square centimeters.
The number of hairs in a specific area.
The most potent natural androgen in humans. Testosterone is converted to DHT by the enzyme 5-alpha reductase. It is believed that DHT is the key androgen required for the induction of MPHL.
The number of hairs in the donor area measured per square centimeter. In general, patients require a donor density of at least 40 FU/cm2 to be considered for transplants.
A term that refers to the number of follicular units per square centimeter.
The majority of human hair shafts that emerge from the scalp as single, 2, and 3-hair groupings. These are the visible superficial portion of a distinctive histologic structure known as the follicular unit The follicular unit consists of one to four, and occasionally five terminal hair follicles, one, or rarely two vellus follicles, the associated sebaceous lobules, the ions of the arrector pili muscles, its neural and vascular plexuses and the fine adventitial collagen that surrounds and defines the unit.
Follicular Unit Dissection
A technique in which naturally occurring, individual follicular units are dissected from donor tissue that has been removed as a single strip. Stereo-microscopic dissection is required.
Follicular Unit Extraction (FUE)
A method of graft harvest whereby punches of various types are used to remove follicular units from the donor region one at a time.
Follicular Unit Graft
A graft consisting of a single follicular unit.
The tubular connection between the epidermal surface and the most distal part of the inner root sheath containing the hair shaft.
A product of the concentration of hairs and the size or caliber of each individual hair.
A strand of hair and its root that is extracted from the donor area and transplanted into the recipient area during hair restoration surgery.
Hair follicles that have been harvested from the donor area and are ready for transplantation into the recipient area of the scalp.
A surgical technique that transfers hair follicles from the donor area to the recipient area. The hair transplantation process consists of two parts: 1) removing the donor follicles and 2) placing them back into the skin.
A prominent part of the largest visible feature of the face. Creating a natural hairline is one of the most important elements of a successful hair transplant. The goal is to achieve the age-appropriate look that will sustain a natural appearance with the future progression of hair loss.
The term used to describe removing hair from the donor area.
Lateral Slit (perpendicular,coronal)
Incisions made perpendicular to the direction of hair growth. The lateral slit technique gives the hair restoration surgeon the ability to control the angle, direction and orientation of the transplanted hair.
An area where hair loss has occurred and hair follicles will be implanted during a hair transplant procedure. There are many methods of creating recipient sites including lightning blades, minde blades, custom-cut razor blades, and various needles.
Slivers and Slivering
Dividing the donor strip into sections of variable widths according to the desired graft size called as slivering. The slivering technique has been compared to slicing a loaf of bread, an analogy in which the loaf is the strip and the emerging slices are the slivers. Creating the ideal sliver without transection is the most difficult step in graft preparation. The use of magnification equipment is essential for the creation of slivers
Cells that reside in rather undifferentiated, quiescent states and form precursors, transient amplifying cells, that provide further proliferation and differentiation into the different cell types. Hair follicle stem cells are multi-potent, capable of proliferation and able to give rise to all cell types of the hair, the epidermis and the sebaceous gland.
A technique for harvesting donor hair that involves the excising of a horizontal section of safe donor hair from the occipital, parietal and occasionally temporal regions. The resulting wound is sutured or stapled and leaves a linear scar.
This refers to the removal of the dermis and other undesired perifollicular tissues of a graft under the microscope with the aim of slimming the graft.