The average Caucasian individual is born with 50,000 fu (follicular units) on their scalp. The average density is 100 fu./cm squared. An individual with advance hair loss, Norwood 6 or 7, usually has on average about 300 cm square of bald scalp. To restore this individual to his original density would require about 30,000 fu (300x100). That is more follicular units than the total remaining on the heads of these follicular unit challenged individuals. Fortunately, it is not necessary to achieve such density. It has been shown that the threshold for detection of thinning for the human eye is below 50 fu/cm sq. Even then, 15,000 fu is required to stay above the threshold of detectability of thinning. Employing modern hair restoration techniques, one is able to obtain very pleasing outcomes for the majority of these individuals with advance hair loss, while employing much lower numbers of follicular units.
The key to successful hair restoration outcomes then lies in the use of these state of the art hair restoration techniques, since it is always the patient with the most need that has the least donor available for hair transplantation. No one ever complains about getting too much hair, hence it is usually best to do the largest session the patient can afford. With favorable hair characteristics, and reasonable patient expectations we can achieve excellent results in as little as one to two procedures.
The term megasession in hair restoration has been an upward moving target. Not too long ago 1000 to 1500 fu was considered a megasession. The use of binocular microscopy to sliver and trim the follicular units has greatly improved our donor yields, on average increasing donor yields by about 25%. Optimal donor harvesting delivers higher yields while conserving this limited resource. Hence, today we are able to offer properly selected patients the option of maximizing their hair restoration outcomes with cases that have surged to the five to six thousand levels. Indeed Rome was not build in a day, but it is nice to have the option to minimize the need for multiple procedures, while maximizing our patient’s hair restoration outcomes.