fig9

Figure 9. Statistics of linear growth rates in vivo and in situ and after grafting. This graph presents statistics on linear hair growth rates [Y-axis: LHGR µm/day; averages with standard deviation (blue and empty bars, respectively)] from a previously published study involving male participants [90 PTGs from healthy controls (C) and 110 from subjects affected with patterned hair loss (Hamilton classification with severity grades I to V; HI to HV ^[4])]. The hair diameters (categorized on the X-axis as 20-30 µm, 40-50 µm, and ≥ 60 µm, respectively, for miniaturized, intermediate, and terminal) clearly influence LHGR according to clinical status (control vs. patients). In vivo and in situ LHGR are shown in comparison with average growth rates from grafted follicles before MTS treatment [grafts; red bar; an average of 17 data points with standard deviation (empty bar)]. Taking hair diameter into account, the growth rates of reactivated grafts (represented by green and yellow dots after MTS, respectively, for proximal and distal grafts at the extreme right of the bar graph) barely reached 50% of the initial growth rates. In any case, LHGR were lower than the in vivo recorded growth rates observed in the thinnest scalp hair in situ^[4,14]. MTS: Minoxidil lotion; LHGR: linear hair growth rate measurements; PTGs: phototrichogram.