The amount of transplanted hair required for a dense appearance varies from individual to individual, because there are several factors to consider. The size of the patients head, hair thickness and balding pattern all play a vital role in the appearance of the result. In this article, we will go over a few key factors that determine how many grafts a patient requires to achieve a good cosmetic result.
The type of hair a patient has will determine the amount of grafts they require to achieve a dense apperance to their hair transplant. Hair characteristics are determined by caliber (hair shaft diameter), color and texture. For example a patient with fine straight hair requires more follicular units per square centimeter to achieve visual density than a patient with thick curly hair. The reason curly thick hair requires less hair to achieve visual density is because the hair follicles decrease the surface area, which means the hair will cover more scalp. The color of the hair will also effect the visual density of ahair restoration procedure, because we see the scalp through hair. Patients with less contrast between the color of their hair and scalp will have a denser overall appearance. For example patients with light skin and light hair will appear to have a fuller head of hair than patients with dark hair and light skin, because the contrast is easily detected by the human eye.Norwood classification and density The amount of grafts a patient requires also depends on their level of hair loss or balding pattern. A patient with a minimal amount of hair loss may only require 1,000 grafts while a patient with extensive androgenic alopecia or genetic hair loss may require upwards to 7,000 grafts. Prior to experiencing any hair loss, most individuals are born with roughly 100,000 hairs on their head. This breaksdown to about 50,000 follicular units, thus requiring up to 25,000 grafts to fully restore the entire top of the scalp (assuming the front, mid section and vertex are completely bald). The average patients donor supply can range from 4,000 grafts-10,000 follicular unit grafts. Fortunately, the average donor supply can restore the appearance of fullness in the front two thirds of the scalp with some coverage in the crown. Prior to hair loss most individuals had around 90-100 follicular units per square centimeter, most qualified hair transplant surgeons can safely transplant around 40-60 follicular units per square centimeter. The naked eye can not detect hair loss until more than 50% of hair has been lost, which means a patient that once had 100 follicular units per square centimeter can transplant 50 follicular units per square centimeter without any decrease in visual density. Conclusion The amount of grafts a patient requires for dense looking result depends on the aforementioned factors, but also on the individuals own perception. While a hair transplant result may appear visually dense, this is not true density, but merely the "illusion" of density. Therefore, some patients may find themselves wanting more hair to achieve fullness and density under any circumstance. Unfortunately, donor hair is finite and a precious resource that may not be abundant enough to cover the entire scalp with ultra-high density. However, in most cases patients have enough donor hair to achieve good density with acceptable coverage.