Comparison Between Liquid Fibrin and Soft Laser Effects on Healing and Relapse After Lip Repositioning Surgery

Comparison Between The Effect of Liquid Platelet-Rich Fibrin and Low-Level Laser Therapy on Enhancing Healing and Reducing Relapse After Lip Repositioning Surgery

A gummy smile can negatively affect a patient's self-confidence and satisfaction with their appearance, leading many individuals to seek effective esthetic solutions. The etiology of this condition varies and may include vertical maxillary excess, short upper lip, hyperactive upper lip, gingival enlargement, or altered passive eruption.

Lip Repositioning Surgery is one of the minimally invasive esthetic surgical procedures used to reduce the amount of gingival display during smiling. Despite its effectiveness, this surgery may be associated with challenges such as pain, swelling, delayed wound healing, and the possibility of postoperative relapse over time, which could compromise both esthetic and functional outcomes.

To overcome these challenges and enhance surgical outcomes, adjunctive techniques have been introduced to promote healing and determine whether enhancing the biological healing process can reduce the rate of relapse after LRS. Among the most prominent of these are Injectable Platelet-Rich Fibrin (i-PRF) and Low-Level Laser Therapy (LLLT).

Study Overview

• Status: Recruiting
• Conditions: Gummy Smile
• Intervention / Treatment: Other: Liquid Platelet-Rich Fibrin group; Other: low-level laser group

• Study Type: Interventional
• Enrollment (Estimated): 22
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Tarek Qasem, DDS MSc PhD; Phone Number: +963 933432778; Email: Tarek2.qasem@damascusuniversity.edu.sy
• Study Contact Backup: Name: Walaa albarry, DDS; Phone Number: +963 996766302; Email: walaa9.albarry.@damascusuniversity.edu.sy

Study Locations

• Syria
  • Rif-dimashq Governorate
    • Damascus, Rif-dimashq Governorate, Syria
      • Recruiting
      • Faculty of Dentistry, Damascus university , Syria.
      • Contact: Mohammad Younis Hajeer, DDS MSc PhD; Phone Number: +963 940404840; Email: myhajeer@gmail.com
      • Principal Investigator: Walaa albarry, DDS

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Patients of both genders.
2. Patients presenting with a gummy smile in the maxillary anterior region (more than 3 mm) due to upper lip hypermobility.
3. Age 18-50 years.
4. Systemically healthy individuals, classified as ASA physical status I or II according to the American Society of Anesthesiologists (ASA) classification; that is, patients without systemic disease or with mild, well-controlled systemic conditions.
5. Patients with good oral hygiene, defined as an O'Leary Plaque Index ≤ 40%.
6. No previous lip repositioning surgery.

Exclusion Criteria:

1. Pregnancy and lactation.
2. Individuals with a previous history of receiving facial Botox or filler injections.
3. Systemic diseases or conditions that contraindicate the use of local anesthesia.
4. Any physical condition that impairs the ability to perform proper oral hygiene measures.
5. Patients who are smokers or alcohol consumers.
6. Inability or unwillingness to cooperate.
7. In adequate width of attached gingiva.
8. Vertical maxillary excess (moderate to severe) requiring orthognathic intervention.
9. Short upper lip
10. Gingival display primarily caused by altered passive eruption requiring crown lengthening.

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: Liquid Platelet-Rich Fibrin group; This group will consist of 11 patients presenting with excessive gingival display due to upper lip hypermobility. Each patient will undergo lip repositioning surgery, followed by immediate injection of Liquid Platelet-Rich Fibrin after completion of the surgical procedure.	Other: Liquid Platelet-Rich Fibrin group; A partial thickness elliptical mucogingival incision was made from the mesial of the central incisor to the mesial of the first molar bilaterally with preservation of the frenulum; vertical height set to twice the excessive gingival display (2:1 ratio), lower margin 1 mm coronal to the mucogingival junction. Epithelium elevated to expose connective tissue (preserving minor salivary glands). Periosteal sutures (4-0 Vicryl, 2-3 per side) placed where connective tissue ≥0.5 mm ; incision edges approximated with simple interrupted 4-0 silk sutures. 20 mL blood collected into additive-free plastic tubes and centrifuged at 300 × g for 5 minutes. The Liquid Platelet-Rich Fibrin layer was aspirated and injected immediately after surgery along incision margins and surrounding tissue at 1 mm depth, multiple points 2-3 mm apart (≈0.1 mL per injection) to achieve homogeneous distribution.
Experimental: Low-Level Laser group; This group will consist of 11 patients presenting with excessive gingival display due to upper lip hypermobility. Each patient will undergo lip repositioning surgery, followed by immediate application of low-level laser therapy (LLLT) after completion of the surgical procedure and at 3,7,10, and 14 days after surgery.	Other: low-level laser group; A partial thickness elliptical mucogingival incision was made from the mesial of the central incisor to the mesial of the first molar bilaterally with preservation of the frenulum; vertical height set to twice the excessive gingival display (2:1 ratio), lower margin 1 mm coronal to the mucogingival junction. Epithelium elevated to expose connective tissue (preserving minor salivary glands). Periosteal sutures (4-0 Vicryl, 2-3 per side) placed where connective tissue ≥0.5 mm to ; incision edges approximated with simple interrupted 4-0 silk sutures. low-level laser applied to the surgical site (635nm, 200 mW) as part of the post-surgical treatment and at 3,7,10, and 14 days after surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gingival display (mm)	Measured in millimeters from the lowest point of the upper lip vermilion border to the free gingival margin of the maxillary teeth (from right second premolar to left second premolar) during full smile.	Baseline and 1, 3 and 6 months postoperatively
Wound Healing Index	Wound healing will be assessed using the Wound Healing Index (Huang, Neiva, and Wang, 2005). This is a categorical scale with scores ranging from 1 to 3: = poor healing (significant gingival swelling or redness, severe patient discomfort, slough formation with suppuration);; = good healing (mild gingival swelling or redness, mild patient discomfort, slough formation without suppuration);; = complete healing (no gingival swelling, redness, suppuration, or patient discomfort, and no slough formation). Higher scores indicate better healing outcomes.	weekly for 4 weeks postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain (VAS 0-100)	Postoperative pain assessed using patient self-reported Visual Analogue Scale (VAS, 0-100), where 0 indicates no pain and 100 indicates worst possible pain. Pain will be recorded daily for the first 7 days after surgery.	Days 1-7 postoperatively
Postoperative Edema/Swelling	Postoperative edema/swelling assessed on the third day after surgery using a clinician-reported rating scale: 0 = no visible oedema; = slight oedema (intra- oral swelling in the surgical zone);; = moderate oedema (extra- oral swelling in the surgical area);; = severe oedema (extra- oral swelling extending the surgical site) and/or visible hematoma and ecchymosis	Day 3 postoperatively
Esthetic Satisfaction (VAS 0-100)	Esthetic satisfaction assessed using patient self-reported Visual Analogue Scale (VAS, 0-100), where 0 indicates completely dissatisfied and 100 indicates completely satisfied. Evaluation will be performed 6 months postoperatively.	6 months postoperatively
Upper Lip External Length	Measured from the base of the nose to the lower edge of the vermilion border of the upper lip, assessed at both resting and maximum smiling positions	Baseline, 1,3 and 6 months postoperatively
Upper Lip Internal Length	Measured at rest and smile to assess the dimensions of the internal upper lip	Baseline, 1, 3 and 6 months postoperatively
Intraoperative complications	Any complication during the surgery will be recorded for reporting. A score of 0 will be assigned when none of complications are observed, whereas a score of 1 will be assigned if any complication occurs.	During surgery
Post-operative complications	Any complication related to the surgical intervention and healing following the surgical treatment such as infection, or sensory disturbances will be recorded for reporting. A score of 0 will be assigned when none of these complications are observed, whereas a score of 1 will be assigned if any of them occur.	First week postoperatively

Collaborators and Investigators

• Sponsor: Damascus University
• Investigators: Study Director: Tarek Qasem, DDS MSc PhD, Faculty of Dentistry, Damascus university, Syria.

Publications and helpful links

General Publications

• Miron RJ, Gruber R, Farshidfar N, Sculean A, Zhang Y. Ten years of injectable platelet-rich fibrin. Periodontol 2000. 2024 Feb;94(1):92-113. doi: 10.1111/prd.12538. Epub 2023 Nov 30.
• Alammar A, Heshmeh O, Mounajjed R, Goodson M, Hamadah O. A comparison between modified and conventional surgical techniques for surgical lip repositioning in the management of the gummy smile. J Esthet Restor Dent. 2018 Nov;30(6):523-531. doi: 10.1111/jerd.12433. Epub 2018 Nov 9.
• Farshidfar N, Amiri MA, Estrin NE, Ahmad P, Sculean A, Zhang Y, Miron RJ. Platelet-rich plasma (PRP) versus injectable platelet-rich fibrin (i-PRF): A systematic review across all fields of medicine. Periodontol 2000. 2025 Mar 24. doi: 10.1111/prd.12626. Online ahead of print.
• Sun G, Tuner J. Low-level laser therapy in dentistry. Dent Clin North Am. 2004 Oct;48(4):1061-76, viii. doi: 10.1016/j.cden.2004.05.004.
• Tawfik OK, El-Nahass HE, Shipman P, Looney SW, Cutler CW, Brunner M. Lip repositioning for the treatment of excess gingival display: A systematic review. J Esthet Restor Dent. 2018 Mar;30(2):101-112. doi: 10.1111/jerd.12352. Epub 2017 Nov 27.
• AlJasser RN. A Modified Approach in Lip Repositioning Surgery for Excessive Gingival Display to Minimize Post-Surgical Relapse: A Randomized Controlled Clinical Trial. Diagnostics (Basel). 2023 Feb 14;13(4):716. doi: 10.3390/diagnostics13040716.
• Tjan AH, Miller GD, The JG. Some esthetic factors in a smile. J Prosthet Dent. 1984 Jan;51(1):24-8. doi: 10.1016/s0022-3913(84)80097-9.
• Robbins JW. Differential diagnosis and treatment of excess gingival display. Pract Periodontics Aesthet Dent. 1999 Mar;11(2):265-72; quiz 273.

Study record dates

Study Major Dates

• Study Start (Actual): April 20, 2026
• Primary Completion (Estimated): January 31, 2027
• Study Completion (Estimated): January 31, 2027

Study Registration Dates

• First Submitted: April 9, 2026
• First Submitted That Met QC Criteria: April 9, 2026
• First Posted (Actual): April 15, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 24, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Wound healing; Low-Level Laser Therapy (LLLT); Gummy smile; Excessive gingival display; Injectable Platelet-Rich Fibrin (i-PRF); Lip Repositioning Surgery; Liquid Platelet-Rich Fibrin; Postoperative relapse; Gingival display reduction; Esthetic dentistry
• Other Study ID Numbers: UDDS-Perio-2026-02

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