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Guo et al. The distribution of hair in Chinese

ANOVA and Dunnett’s T3 pairwise comparison Types of follicular units
were used for data with heterogeneity of variance. Results are shown in Table 3. One-hair FUs
Correlation analysis was performed using Spearman accounted for 28.38%, 2-hair FUs accounted for
correlation analysis. P < 0.05 indicated that a 52.62%, 3-hair FUs accounted for 17.48%, 4-hair FUs
difference was statistically significant. accounted for 1.30%, and 5-hair FUs accounted for
0.21%. No FUs comprising 6 hairs and above were
RESULTS found in our sample.

Demographic characteristics Correlation analysis between FU density and age
The selected 146 healthy Han Chinese included 80 males To analyze the relationship between FU density at
and 66 females and had a mean age of 44.47 ± 14.53 various sites and age, we conducted correlation
years. The 41 alopecia patients included 36 males analyses on the FU density at three sites according to
and 5 females, and had a mean age of 41.24 ± 10.71 age. The results are shown in Table 4. The FU density at
years. the three sites exhibited negative correlations with age.

Comparisons of FU density and hair density DISCUSSION
in healthy Han Chinese
Results are shown in Table 1. The overall FU density Headington found that hairs are not uniformly distributed
2
of the population was 74.36 ± 13.33 units/cm and hair singly, but instead grow as a unit of 1-5 hairs. Each unit
2
density was 143.33 ± 28.08 hairs/cm . The differences has a relatively independent sebaceous gland, erector
between males and females (P > 0.05) were not pili muscles, and perifollicular vascular plexus and nerve
[6]
statistically significant. FU density and hair density fibers, which form a FU . FUT and FUE has been
were high in the vertex and occipital regions but low two primary surgical methods for hair transplantation
due to their high postoperative hair survival rate
in the temporal region. The difference was statistically and natural postoperative appearance . However,
[7]
significant (P < 0.001).
patients detailed evaluation before hair transplantation
surgery, including determination of the amount of
Comparisons of FU density and hair density donor site to excise or extract. Thus, the theoretical
in the occipital region of AGA patients support of data on hair distribution density is needed.
Results are shown in Table 2. The FU density was There are differences in hair among various races.
2
77.78 ± 2.99 units/cm and hair density was 148.12 ± Previous research has indicated that there are
6.98 hairs/cm , which were lower than the values in the substantial differences in hair density among whites,
2
occipital region of healthy Han Chinese. The differences blacks, and Asians . Thus, the populations of various
[5]
were statistically significant (P < 0.001). races usually require different areas of donor sites.
Table 1: Distribution of follicular unit and hair counts in Han Chinese (mean ± SD)
2
2
Density of follicular units (units/cm ) Hair density (hairs/cm )
Total Males (n = 80) Females (n = 66) Total Males (n = 80) Females (n = 66)
Vertex 83.32 ± 7.75 83.56 ± 7.88 83.02 ± 7.64* 160.95 ± 20.66 161.33 ± 21.00 160.50 ± 20.40 #
Occipital 82.66 ± 4.12 83.05 ± 4.16 82.20 ± 4.05* 158.90 ± 13.41 160.15 ± 13.26 157.39 ± 13.54 #
Temporal 57.10 ± 2.97 57.50 ± 2.88 56.62 ± 3.02* 110.14 ± 10.17 111.20 ± 9.57 108.85 ± 10.79 #
Overall 74.36 ± 13.33 74.70 ± 13.33 73.94 ± 13.36* 143.33 ± 28.08 144.23 ± 27.96 142.25 ± 28.26 #
0.751 0.940 0.828 0.680 0.965 0.828
P 1
0.000 0.000 0.000 0.000 0.000 0.000
P 2
0.000 0.000 0.000 0.000 0.000 0.000
P 3
#
P 1 : vertex vs. occipital; P 2 : vertex vs. temporal; P 3 : occipital vs. temporal. Based on a comparison with males, *P > 0.05, P > 0.05
Table 2: Distribution of occipital follicular unit and hair counts of AGA patients and healthy Han Chinese (mean ±
SD)
2
2
Density of follicular units (units/cm ) Hair density (hairs/cm )
Total Males Females Total Males Females
AGA group 77.78 ± 2.99 77.42 ± 2.89 80.40 ± 2.51 148.12 ± 6.98 147.11 ± 6.59 155.40 ± 5.68
Healthy group 82.66 ± 4.12 83.05 ± 4.16 82.20 ± 4.05 158.90 ± 13.41 160.15 ± 13.26 157.39 ± 13.54
P 0.000 0.000 0.008 0.000 0.000 0.007
AGA: androgenetic alopecia
152 Plastic and Aesthetic Research ¦ Volume 4 ¦ September 28, 2017