Gingival Augmentation

Definition

Anatomy Basis

• Free gingiva: forms the 2-3 mm deep sulcus in health
• Attached gingiva: firmly adherent to underlying alveolar bone
• Alveolar mucosa: non-keratinized, extends apically from the attached gingiva into the vestibule

Indications for Gingival Augmentation

Classification of Procedures

1. Free Gingival Graft (FGG)

• Donor site: Full-thickness wedge of epithelium + underlying connective tissue from the hard palate
• Best for: Widening the band of keratinized tissue, especially in thin gingival biotypes
• Advantage: Most effective technique for increasing keratinized tissue width (KTW)
• Limitation: Color mismatch (appears "patchy" or lighter), slower re-epithelialization, donor site heals by secondary intention
• Outcome: Mean gain of ~4+ mm of attached gingiva when used in strip technique for multiple teeth

2. Subepithelial Connective Tissue Graft (SCTG / CTG)

• Donor site: Subepithelial connective tissue harvested via a palatal flap (surface epithelium preserved, heals faster)
• Best for: Root coverage + gingival augmentation with aesthetic concern
• Advantage: Better color match, dual blood supply (periosteum + overlying flap), faster healing
• Combined with: Coronally advanced flap (CAF), tunnel technique, laterally positioned flap
• Gold standard for root coverage - SCTG+CAF significantly outperforms CAF alone for:
  • Mean root coverage (MRC+13.4%, p<0.01)
  • Complete root coverage (CRC+14.4%, p<0.01)
  • Keratinized tissue width gain (+0.71 mm, p<0.01)
• According to the AAP 2022 systematic review and NMA (PMID 36279123), SCTG+CAF is statistically superior to biologics (EMD, PRF) as an adjunct to CAF

3. Pedicle Grafts

• Laterally positioned flap (lateral sliding flap): Donor tissue is moved laterally from adjacent gingiva; good color match but limited by donor site availability
• Coronally advanced flap (CAF): Flap is moved coronally for root coverage, typically without augmenting keratinized width
• Double pedicle (bilateral papilla) flap: Adjacent papillae are raised and joined over the defect

4. Apically Repositioned Flap (APF)

• The existing gingiva is repositioned apically to expose alveolar bone and allow periosteum-derived epithelialization
• Increases the zone of attached gingiva by using the periosteum as a recipient bed
• Often combined with free grafts for larger defects

5. Allograft / Xenograft Substitutes

• Acellular dermal matrix (ADM / AlloDerm): Freeze-dried human dermal allograft; useful when palatal donor site is inadequate or multiple teeth need coverage (3+ teeth)
• Collagen matrices (e.g., Mucograft): Xenograft porcine-derived; used to augment keratinized tissue around implants, avoids donor site morbidity
• Slightly inferior outcomes vs. autologous CTG in KTW and thickness gain, but comparable in some parameters

6. Biologics as Adjuncts

• Enamel matrix derivative (EMD) + CAF: Showed a trend toward better root coverage but did not reach statistical significance vs. CAF alone
• Platelet-rich fibrin (PRF) + CAF: No statistically significant improvement over CAF alone
• rhPDGF-BB: Limited evidence in gingival augmentation specifically
• Conclusion: SCTG remains the gold standard; biologics do not replace it

Surgical Steps (Free Gingival Graft - Classic)

1. Recipient site preparation: Incise at the mucogingival junction; create a periosteal bed by dissecting mucosa away from periosteum, exposing connective tissue/periosteum
2. Measure defect: Width and height of augmentation needed
3. Harvest donor tissue: From ipsilateral or contralateral hard palate, 1.5-2 mm thick, epithelium included
4. Graft placement: Graft is sutured to recipient periosteal bed (sling or interrupted sutures), immobilized
5. Donor site: Covered with periodontal dressing or collagen sponge, heals by secondary intention
6. Healing: Revascularization begins at ~4-5 days; full incorporation by ~4-6 weeks; mature appearance at 3 months

Outcomes and Long-Term Stability

• Gains in gingival margin position and soft tissue phenotype are largely maintained over time
• Thicker gingival biotype achieved post-surgically tends to remain stable
• Patient compliance and plaque control are critical determinants of long-term success

Complications

Key Comparison: FGG vs. CTG

Recent Evidence Highlights

• SCTG + CAF remains the gold standard for root coverage and gingival augmentation (AAP, 2022 - PMID 36279123)
• Biologics (EMD, PRF) have not demonstrated consistent benefit over SCTG
• Long-term stability of mucogingival outcomes is supported, especially with adequate tissue phenotype and ongoing maintenance (PMID 37963451)
• Acellular dermal matrices and xenograft collagen matrices are viable alternatives when autologous tissue is insufficient

Free Soft Tissue Autograft

Definition

1. Free Gingival Graft (FGG)
2. Subepithelial Connective Tissue Graft (SCTG / CTG)

Classification

Free Soft Tissue Autografts
├── Free Gingival Graft (FGG)
│   ├── Classical FGG (full thickness: epithelium + CT)
│   ├── Modified FGG (ModFGG)
│   └── De-epithelialized FGG (converted to CTG extraorally)
└── Subepithelial Connective Tissue Graft (SCTG/CTG)
    ├── Trap-door / envelope technique
    ├── Single-incision technique
    └── Double-incision (parallel incision) technique

1. Free Gingival Graft (FGG)

Description

Indications

• Inadequate width of keratinized/attached gingiva (<1-2 mm)
• Pre-prosthetic or pre-implant augmentation of keratinized tissue
• Miller Class I or II gingival recession where aesthetics is not the primary concern
• Shallow palatal vault making SCTG harvest difficult
• Pre-orthodontic gingival augmentation in thin biotypes
• Vestibuloplasty (increasing sulcus depth)
• Around implants requiring keratinized tissue width (KTW) increase

Donor Site

• Hard palate: from the distal of the canine to the mesial of the first molar, at least 2 mm from the gingival margin and 2 mm from the greater palatine neurovascular bundle (runs ~7-12 mm from the gingival margins)
• Area between premolars preferred - greater tissue thickness
• Thickness harvested: ~1.5-2 mm (including epithelium + ~1-1.5 mm of CT)
• Donor wound heals by secondary intention; covered with periodontal dressing or hemostatic collagen

Recipient Site Preparation

1. Local anesthesia (regional blocks preferred to avoid tissue distortion)
2. Horizontal incision at or just below the mucogingival junction
3. Split-thickness flap elevation - periosteum is left intact on bone (creates vascular bed)
4. Area is extended to accommodate graft size
5. Root surface is planed and conditioned if root coverage is intended (citric acid, EDTA, or tetracycline)

Graft Harvesting (FGG)

1. Template made from foil to size-match the recipient bed
2. Horizontal incisions outline the donor area
3. Graft is dissected at ~1.5-2 mm thickness, keeping uniform depth
4. Graft is trimmed of excess fatty/glandular tissue on its inner surface
5. Donor site covered and sutured where possible or protected with periodontal pack

Graft Placement and Suturing

1. Graft placed on the periosteal bed with epithelial surface facing outward
2. Adaptation using interrupted or continuous sutures (4-0 or 5-0 resorbable or non-resorbable)
3. Immobilization is critical - any micromovement disrupts revascularization
4. Pressure applied for several minutes to minimize dead space

Healing Stages of FGG

Outcomes

• Superior to all techniques for keratinized tissue width (KTW) gain
• APF + FGG = most effective procedure for peri-implant KTW augmentation (MD: 0.22-4.11 mm) per the 2026 NMA, Cafasso et al. (PMID 41858220)
• Root coverage achievable but color mismatch is common ("patchy," lighter appearance)
• Mean KTW gain reported ~4+ mm in the strip technique for multi-tooth defects
• Long-term stability maintained when plaque control is adequate

2. Subepithelial Connective Tissue Graft (SCTG / CTG)

Description

Indications

• Miller Class I and II gingival recession with aesthetic concern (anterior teeth)
• Root hypersensitivity from recession
• Root coverage (single or multiple recession defects)
• Augmenting gingival thickness (increasing biotype)
• Peri-implant mucosal thickness augmentation
• Pre-prosthetic augmentation
• Coverage of cervical abrasion/non-carious cervical lesions with recession

Donor Site and Harvesting Techniques

• Two horizontal incisions: one ~2 mm from the gingival margin, one parallel and apical
• Vertical releasing incision at one end
• Flap is lifted as a "trap door" - connective tissue harvested, palatal flap re-approximated
• Advantages: good visibility, predictable thickness
• Disadvantage: more complex closure

• One linear incision is made, and the flap is undermined via split-thickness dissection
• CT harvested through this single access
• Advantages: reduced donor site wound, primary closure, less postoperative pain
• Disadvantage: blind dissection, requires high skill

• Two parallel incisions allow removal of a CT strip
• Good for obtaining thicker, longer grafts

• Classic FGG is harvested, then the epithelium is removed extraorally with a fresh blade
• Yields dense, fibre-rich CT; donor site heals by secondary intention (more morbidity)
• Reserved for cases needing high-density tissue

Recipient Site and Placement

• Combined with Coronally Advanced Flap (CAF) - most common
• Combined with Tunnel technique - for multiple adjacent recessions; minimally invasive, excellent aesthetics
• Combined with Laterally Positioned Flap
• Graft is secured underneath the overlying flap, receiving dual blood supply
• Sutures secure graft and close the flap coronally

Outcomes

• Gold standard for root coverage in Miller Class I/II recession
• CAF + CTG: long-term complete root coverage in ≥2/3 of patients at 5+ years of follow-up per the Bertl et al. 2021 systematic review (PMID 33565266)
• Best material for mucosal/tissue thickness increase (peri-implant): CTG outperforms all matrices and FGG for mucosal thickness gain per the Tommasato et al. 2024 NMA (PMID 38704784)
• Superior color match vs. FGG
• SCTG + CAF significantly outperforms biologics (EMD, PRF) for mean root coverage (MRC +13.4%) and complete root coverage (CRC +14.4%) (PMID 36279123)

Comparison: FGG vs. SCTG

Factors Affecting Graft Success

Contraindications / Relative Contraindications

• Uncontrolled periodontal disease (active infection)
• Heavy smoking (relative - reduces success rate)
• Shallow palatal vault (limits FGG and CTG harvest depth)
• Insufficient palatal tissue thickness
• Medically compromised patients (uncontrolled diabetes, anticoagulants, immunosuppressed)
• Miller Class III/IV (Cairo RT2/RT3) recession - complete root coverage not predictable

Key Evidence Summary