Hair, Graft and Follicular Unit
Differences : Anatomical Basis Of Follicular Units & Ethnic Variations In Hair Characteristics.
Grafts vs. Hairs
14 grafts containing 39 hairs
The Follicular Unit (FU)
- 1–4 Hair Follicles
- Sebaceous (Oil) Glands
- Arrector Pili Muscle
- Neurovascular Plexus
- Connective Tissue Sheath
Graft vs. Hair Distinction
Graft: One transplanted Follicular Unit (contains 1-4 hairs).
Hair: The individual shafts within that graft.
Example: 2,000 grafts typically yields 3,500–4,500 hairs.
Ethnic Variations in Hair Anatomy
Comparative Hair Characteristics by Ethnicity
| Characteristic | Caucasian | African | Asian |
|---|---|---|---|
| Hair Density (hairs/cm²) | ~200 | ~160 | ~170 |
| FU Density (units/cm²) | ~100 | ~60 | ~90 |
| Hair-Graft Ratio | 2.3 | 2.3 | 1.8 |
| Shaft Diameter | 0.07 mm | 0.06 mm | 0.08 mm |
| Hair Shape | Curly/Wavy | Curly/Coiled | Straight |
| Follicle Length | ~4.5 mm | Variable | ~5.5 mm |
Follicular Unit Distribution in Chinese Scalps
Regional Density (FU/cm²)
| Group | Back |
|---|---|
| Men (Normal) | 80 |
| Men (Bald) | 68 |
| Women (Normal) | 72 |
| Women (Bald) | 69 |
FU Composition (%)
| Group | 1-Hair | 2-Hair | 3-Hair | Ratio |
|---|---|---|---|---|
| Men | 29% | 52% | 17% | 1.92 |
| Women | 33% | 49% | 16% | 1.87 |
Clinical Relevance
Natural Appearance
Transplanting intact FUs supports natural hairline design.
Treatment Planning
Donor density measurement allows coverage calculation.
Donor Management
Efficient harvesting helps preserve donor supply.
Growth Timeline
Understanding the shedding phase supports patient expectations.