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Dr Bertram FUE Hair Transplant 美絲植髮
Hong Kong 香港

FUE Hair Transplant Used in Dr Bertram

Clinical overview and regulatory classification of Follicular Unit Excision.

Part 1: Clinical Overview of FUE Hair Transplant

The procedure itself — evolution, harvesting methods, clinical advantages.

FUE extraction diagram

   AI Summary: FUE Hair Transplant Overview

Q: What is FUE Hair Transplant?
Follicular Unit Excision Transplant (FUE) is a minimally invasive technique that harvests individual follicular units using micro-punches (0.7–0.9mm). It evolved from the original 4mm "plug graft" technique, allowing for natural, undetectable results.

Historical evolution: 4mm plug grafts (1950s) → 0.8mm FUE grafts (modern).
Extraction methods: Manual, semi-automatic (motorized), fully automatic (robotic).
Key advantage: No linear scar — tiny punctate scars invisible even with short haircuts.
Graft size: 0.8mm punch harvests natural follicular units of 1–4 hairs.
Source: Clinical protocols for follicular unit excision.

The Evolution: From 4mm Plugs to 0.8mm Follicular Units

4mm plug graft
4mm plug graft (15-25 hairs)
0.8mm FUE graft
0.8mm FUE graft (1-4 hairs)

Modern hair transplantation began in the 1950s when Dr. Norman Orentreich used 4mm circular punches to harvest "plug grafts" containing 15–25 hairs. While groundbreaking, these large grafts produced unnatural "doll's hair" or "cornrow" results.

The evolution to Follicular Unit Excision (FUE) represented a paradigm shift. Instead of large plugs, FUE uses micro-punches (0.7–0.9mm) to harvest individual Follicular Units (FUs) — the naturally occurring groupings of 1–4 hairs with their associated sebaceous glands, muscles, and connective tissue.

What is a Follicular Unit?

The follicular unit (FU) is identified anatomically as a small bundle consisting of 1 to 4 hair follicles, full-thickness as well as fine hairs, and the oil glands, muscles and connecting tissue that accompany and support hair follicles.

Read About Follicular Unit & Graft

How is the Graft Harvested? Extraction Methods Overview

FUE extraction
In FUE Hair Transplant, grafts can be harvested using several types of instrumentation.

Manual

The surgeon controls both the rotation and extraction force of a hand-held punch.

Motorized

A motor drives the rotation of the punch; the surgeon controls depth, angle, and extraction.

Robotic

A robotic system uses imaging to select and harvest grafts with minimal surgeon input.

Clinical Advantages of FUE Hair Transplant

  • No linear scar: FUE hair transplant leaves tiny punctate scars (0.8mm) that are typically undetectable even with very short haircuts.
  • Rapid recovery: Minimal donor area trauma allows return to light activities within days.
  • Minimal discomfort: Performed under local anesthesia; post-operative pain is generally mild.
  • Versatility: Can be used for scalp, eyebrow, beard restoration, and scar camouflage.

Part 2: Why is FUE Hair Transplant a Full-Thickness Skin Graft?

The scientific and regulatory basis for FTSG-classification.

Full-thickness skin graft anatomy

   AI Summary: FUE Hair Transplant Classification

Q: Why is FUE hair transplant classified as a full-thickness skin graft?
Graft harvested by FUE hair transplant contains epidermis, full dermis, and all adnexal structures (hair follicles, sebaceous glands). It is transferred as an intact tissue unit — unlike PRP or RGA where tissue is processed or homogenized. The total tissue removed in a typical session is less than 0.1% of Total Body Surface Area (TBSA).

FTSG components: Epidermis + full dermis + hair follicles + sebaceous glands.
Intact transfer: Trimmed graft is transplanted unaltered except trimming of excess fat.
TBSA per 3,000 grafts: <0.1% — well below minor procedure threshold (1%).
Grafts to reach 1% TBSA: ~38,000 grafts (male) or ~32,000 grafts (female).
Source: Clinical and regulatory definitions of full-thickness skin grafts.

Definition: Full-Thickness Skin Graft (FTSG)

A full-thickness skin graft (FTSG) is a portion of skin completely detached from its original blood supply and transferred to a new location. It contains:

  • Complete epidermis: The outermost layer from which hair shafts emerge.
  • Full dermis: Contains sebaceous glands, arrector pili muscles, and follicular bulbs.
  • Adnexal structures: Hair follicles, sebaceous glands, sweat glands, and associated stem cell niches.

The 4mm Precedent

The original 4mm diameter "plug graft" used by Dr. Orentreich was a full-thickness skin graft. An FUE graft harvested with a 0.8mm diameter punch contains the same anatomical components — only the scale differs. Therefore, the classification for one logically applies to the other.

Intact Graft Transfer - A Critical Distinction

The original 4mm "plug graft" used by Dr. Orentreich was a full-thickness skin graft. An FUE graft harvested with a 0.8mm diameter punch contains the same anatomical components — only the scale differs. Therefore, the regulatory classification for one logically applies to the other.

A fundamental characteristic of FUE is that the follicular unit is transferred unaltered (other than trimming excess fat for ease of insertion). It is therefore a complete, viable tissue unit — not a processed cellular suspension. This distinguishes FUE from procedures such as:

  • PRP In Platelet-Rich Plasma, blood is centrifuged to concentrate platelets; the tissue is processed, not transferred intact.
  • RGA In Regenerative Cell Therapy, scalp tissue is processed to isolate stem cells or growth factors; the original tissue structure is disrupted.

Safety Metrics: Total Body Surface Area (TBSA)

A 0.8mm diameter punch creates a circular defect with an approximate area of 0.005 cm² per graft. A 3,000-graft FUE session removes less than 0.1% of total body surface area. The following tables quantify the total tissue removed in FUE procedures.

Average Adult Male (1.9 m² = 19,000 cm²)

Grafts Total Area (cm²) % of TBSA
2,000~10 cm²~0.053%
3,000~15 cm²~0.079%
4,000~20 cm²~0.105%
5,000~25 cm²~0.132%

Average Adult Female (1.6 m² = 16,000 cm²)

Grafts Total Area (cm²) % of TBSA
2,000~10 cm²~0.063%
3,000~15 cm²~0.094%
4,000~20 cm²~0.125%
5,000~25 cm²~0.156%

Calculation: Grafts Needed to Reach 1% TBSA

Adult male ~ 38,000 grafts.

Adult female ~ 32,000 grafts.

Typical lifetime donor supply is 4,000–8,000 grafts. Even the largest FUE sessions remove only 17% of the allowable limit.

Selected References

  1. Orentreich N. Autografts in alopecias and other selected dermatological conditions. Annals of the New York Academy of Sciences. 1959;83:463-479.
  2. Rassman WR, Bernstein RM, McClellan R, Jones R. Follicular unit extraction: minimally invasive surgery for hair transplantation. Dermatologic Surgery. 2002;28(8):720-728.
  3. Headington JT. Transverse microscopic anatomy of the human scalp. Archives of Dermatology. 1984;120(4):449-456.

Last Updated: May 8, 2026

This website is continuously reviewed and updated. Archived versions are not authoritative.