Volumetric Changes After Free Gingival Graft: Tuberosity vs Palatal Donor Site (VolFGG-TP)

Volumetric Analysis of Recipient and Donor Sites Following Free Gingival Graft Surgery Harvested From Different Palatal Donor Sites: A Randomized Controlled Clinical Trial

This randomized controlled clinical trial evaluated volumetric changes at recipient and donor sites following free gingival graft (FGG) surgery, comparing two different palatal donor regions. Forty systemically healthy non-smoking adults aged 20-40 years with Miller Class I gingival recession defects at the mandibular anterior teeth (teeth 31, 32, 41, and 42) were randomly allocated using a sealed envelope method into two groups based on the donor site: (1) the anterior palatal region (from the distal of the canine to the first molar), and (2) the posterior palatal/tuberosity region (between the first molar and the tuberosity). All grafts were harvested targeting a standardized size of 8x10 mm (80 mm²). Digital intraoral scans (3Shape TRIOS 5) were obtained preoperatively and at 1, 3, and 6 months postoperatively. Volumetric changes at both recipient and donor sites were measured using STL-based superimposition in Exocad software. The aim was to compare time-dependent volumetric change patterns at both the recipient and donor sites between the two donor groups.

Study Overview

• Status: Completed
• Conditions: Gingival Recession; Periodontal Plastic Surgery
• Intervention / Treatment: Procedure: Free Gingival Graft from Anterior Palatal Donor Site; Procedure: Free Gingival Graft from Posterior Palatal / Tuberosity Donor Site

Detailed Description

BACKGROUND:

Free gingival graft (FGG) is a well-established procedure to augment keratinized tissue width and manage gingival recession defects. Despite widespread clinical use, comparative data on volumetric outcomes from different palatal donor sites remain limited, and most existing studies rely on one-dimensional clinical measurements rather than volumetric analysis. Emerging evidence suggests that donor tissue composition may differ between anterior palatal and posterior palatal/tuberosity regions, potentially influencing graft behavior at the recipient site.

STUDY DESIGN:

Single-center, parallel-group, randomized controlled clinical trial with 1:1 allocation via sealed envelope randomization.

INTERVENTION:

All surgical procedures were performed by a single operator under local infiltration anesthesia (Ultracain DS, epinephrine 1:200,000). At the recipient site, a split-thickness recipient bed was prepared and the autogenous free gingival graft was stabilized using five 7-0 polypropylene monofilament sutures. Sutures were removed between days 10-14. At the donor site, no sutures were placed and the wound was left to heal by secondary intention. Grafts were harvested aiming for 8x10 mm dimensions.

OUTCOME ASSESSMENT:

Intraoral scans were acquired at T0 (preoperative baseline), T1 (1 month), T2 (3 months), and T3 (6 months) using a 3Shape TRIOS 5 intraoral scanner and saved as STL files. STL files were superimposed in Exocad using automatic alignment algorithms. Recipient and donor regions of interest were isolated. MeshMixer was used for STL preparation, while final volumetric calculations were performed in Exocad and recorded in mm³. To account for unavoidable minor variations in graft dimensions, volumetric data were mathematically normalized to a theoretical standard graft surface area of 80 mm² (8x10 mm).

STATISTICAL ANALYSIS:

Sample size was calculated a priori using G*Power 3.1 (α=0.05, power=0.80, effect size=0.68), yielding 20 patients per group (40 total). Analyses were conducted in SPSS v22.0 with significance set at p<0.05. Data distribution was assessed using the Shapiro-Wilk test. Within-group time effects were evaluated using Repeated Measures ANOVA; between-group comparisons at each time point were performed using independent samples t-test. Time × donor-site interaction was analyzed to determine whether volumetric change patterns differed between groups over time.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Samsun
    • Samsun, Samsun, Turkey (Türkiye), 55270
      • Ondokuz Mayis University, Faculty of Dentistry, Department of Periodontology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adults aged 20 to 40 years (both male and female)
• Presence of Miller Class I gingival recession at mandibular anterior teeth (teeth 31, 32, 41, and 42)
• Systemically healthy (no known systemic diseases)
• Non-smokers
• Adequate oral hygiene
• Able and willing to provide written informed consent and attend follow-up visits

Exclusion Criteria:

• Pregnancy or lactation
• Current or past smoking
• Diagnosis of diabetes mellitus
• Use of isotretinoin or similar systemic anti-acne medications
• Inadequate oral hygiene
• Current anticoagulant therapy
• Systemic contraindications to periodontal surgery
• History of previous periodontal surgery at the recipient site

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Anterior Palatal Donor Group; Free gingival graft was harvested from the anterior palatal region, defined as the area between the distal of the maxillary canine and the first molar. The graft was targeted to be 8x10 mm (approximately 80 mm²) in dimension. After harvesting, the graft was placed at the recipient site (Miller Class I gingival recession at mandibular anterior teeth 31, 32, 41, 42) and stabilized with five 7-0 polypropylene sutures. The donor site was left to heal by secondary intention without sutures.	Procedure: Free Gingival Graft from Anterior Palatal Donor Site; Free gingival graft (FGG) surgery was performed under local infiltration anesthesia (Ultracain DS, epinephrine 1:200,000) by a single experienced operator. At the recipient site, a split-thickness recipient bed was prepared at the buccal aspect of mandibular anterior teeth presenting Miller Class I gingival recession. The autogenous free gingival graft was harvested from the anterior palatal region, defined as the area between the distal aspect of the maxillary canine and the first molar, targeting dimensions of 8 × 10 mm. The graft was secured at the recipient site using five 7-0 polypropylene monofilament sutures. No sutures were placed at the donor site; the wound was left to heal by secondary intention. Sutures at the recipient site were removed between postoperative days 10 and 14. All patients received standardized postoperative instructions and analgesic recommendations.
Experimental: Posterior Palatal / Tuberosity Donor Group; Free gingival graft was harvested exclusively from the maxillary tuberosity region. The graft was targeted to be 8x10 mm (approximately 80 mm²) in dimension. After harvesting, the graft was placed at the recipient site (Miller Class I gingival recession at mandibular anterior teeth 31, 32, 41, 42) and stabilized with five 7-0 polypropylene sutures. The donor site was left to heal by secondary intention without sutures.	Procedure: Free Gingival Graft from Posterior Palatal / Tuberosity Donor Site; Free gingival graft (FGG) surgery was performed under local infiltration anesthesia (Ultracain DS, epinephrine 1:200,000) by a single experienced operator. At the recipient site, a split-thickness recipient bed was prepared at the buccal aspect of mandibular anterior teeth presenting Miller Class I gingival recession. The autogenous free gingival graft was harvested from the maxillary tuberosity / posterior palatal region, targeting dimensions of 8 × 10 mm. The graft was secured at the recipient site using five 7-0 polypropylene monofilament sutures. No sutures were placed at the donor site; the wound was left to heal by secondary intention. Sutures at the recipient site were removed between postoperative days 10 and 14. All patients received standardized postoperative instructions and analgesic recommendations.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Volumetric change at the recipient site	Standardized volumetric change (mm³) at the recipient site compared with preoperative baseline (T0), measured via three-dimensional STL-based superimposition of intraoral scans (3Shape TRIOS 5) using Exocad software. Volumetric data were mathematically normalized to a theoretical standard graft surface area of 80 mm² (8x10 mm) to account for minor graft size variations. Negative values indicate volume loss; positive values indicate volume gain relative to baseline.	1, 3, and 6 months postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Volumetric change at the donor site	Standardized volumetric change (mm³) at the palatal donor site (either anterior palatal or posterior palatal/tuberosity, as per group allocation) compared with preoperative baseline (T0), measured via three-dimensional STL-based superimposition of intraoral scans (3Shape TRIOS 5) using Exocad software. Negative values indicate volume loss relative to baseline; positive values indicate volume gain relative to baseline.	1, 3, and 6 months postoperatively
Time × donor-site interaction effect on volumetric change at the recipient site	Repeated Measures ANOVA interaction term evaluating whether time-dependent volumetric change patterns at the recipient site differ between the two donor groups (anterior palatal versus posterior palatal/tuberosity). A significant interaction (p<0.05) indicates that volumetric change trajectories across time differ between donor groups.	Across 1, 3, and 6 months postoperatively

Collaborators and Investigators

• Sponsor: Hooman Hashemzadeh
• Investigators: Principal Investigator: Tugrul Kirtiloglu, PHD, Ondokuz Mayıs University; Study Director: Emir Akan, Ondokuz Mayıs University

Publications and helpful links

General Publications

• Parvini P, Galarraga-Vinueza ME, Obreja K, Magini RS, Sader R, Schwarz F. Prospective study assessing three-dimensional changes of mucosal healing following soft tissue augmentation using free gingival grafts. J Periodontol. 2021 Mar;92(3):400-408. doi: 10.1002/JPER.19-0640. Epub 2020 Aug 21.
• Tavelli L, Barootchi S, Siqueira R, Kauffmann F, Majzoub J, Stefanini M, Zucchelli G, Wang HL. Three-Dimensional Volumetric Analysis of the Palatal Donor Site Following Soft Tissue Harvesting. Int J Periodontics Restorative Dent. 2022 May-Jun;42(3):393-399. doi: 10.11607/prd.5268.

Study record dates

Study Major Dates

• Study Start (Actual): December 1, 2023
• Primary Completion (Actual): May 1, 2025
• Study Completion (Actual): May 1, 2025

Study Registration Dates

• First Submitted: April 21, 2026
• First Submitted That Met QC Criteria: April 21, 2026
• First Posted (Actual): April 28, 2026

Study Record Updates

• Last Update Posted (Actual): May 4, 2026
• Last Update Submitted That Met QC Criteria: April 28, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: volumetric analysis; free gingival graft; intraoral scanner; palatal donor site; digital dentistry
• Additional Relevant MeSH Terms: Periodontal Atrophy; Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Gingival Diseases; Gingival Recession
• Other Study ID Numbers: B.30.2.ODM.0.20.08/569

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No