CClinicalTrials.gg
RecruitingNCT07532161Updated Apr 29, 2026

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

An interventional study of Liquid Platelet-Rich Fibrin group and low-level laser group in Gummy Smile, sponsored by Damascus University. Recruiting at 1 site in Syria. Open to participants aged 18 Years to 50 Years. Per ClinicalTrials.gov, last updated 2026-04-29.

Sponsored by Damascus University · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
22
Allocation
Randomized
Ages
18 Years to 50 Years
Sex
All
01

Study summary

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).

02

Conditions studied

  • Gummy Smile

Keywords

  • Excessive gingival display
  • Gummy smile
  • Lip Repositioning Surgery
  • Injectable Platelet-Rich Fibrin (i-PRF)
  • Liquid Platelet-Rich Fibrin
  • Low-Level Laser Therapy (LLLT)
  • Wound healing
  • Postoperative relapse
  • Gingival display reduction
  • Esthetic dentistry
03

Who can participate

Ages eligible
18 Years to 50 Years
Sexes eligible
All
Accepts healthy volunteers
No

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

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.
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Single (Outcomes assessor)
Enrollment
22 participants (estimated)

Study arms

  • 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

  • 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

Interventions

  • OtherLiquid 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.

  • Otherlow-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.

05

What researchers measure

Primary outcomes

  1. 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.

    Time frame: Baseline and 1, 3 and 6 months postoperatively

  2. 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: 1. = poor healing (significant gingival swelling or redness, severe patient discomfort, slough formation with suppuration); 2. = good healing (mild gingival swelling or redness, mild patient discomfort, slough formation without suppuration); 3. = complete healing (no gingival swelling, redness, suppuration, or patient discomfort, and no slough formation). Higher scores indicate better healing outcomes.

    Time frame: weekly for 4 weeks postoperatively

Secondary outcomes

  1. 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.

    Time frame: Days 1-7 postoperatively

  2. Postoperative Edema/Swelling

    Postoperative edema/swelling assessed on the third day after surgery using a clinician-reported rating scale: 0 = no visible oedema; 1. = slight oedema (intra- oral swelling in the surgical zone); 2. = moderate oedema (extra- oral swelling in the surgical area); 3. = severe oedema (extra- oral swelling extending the surgical site) and/or visible hematoma and ecchymosis

    Time frame: Day 3 postoperatively

  3. 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.

    Time frame: 6 months postoperatively

  4. 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

    Time frame: Baseline, 1,3 and 6 months postoperatively

  5. Upper Lip Internal Length

    Measured at rest and smile to assess the dimensions of the internal upper lip

    Time frame: Baseline, 1, 3 and 6 months postoperatively

  6. 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.

    Time frame: During surgery

  7. 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.

    Time frame: First week postoperatively

06

Study locations

1 of 1 sites recruiting
  • Faculty of Dentistry, Damascus university , Syria.
    Damascus, Rif-dimashq Governorate, Syria
    • Mohammad Younis Hajeer, DDS MSc PhD · Contact · myhajeer@gmail.com · +963 940404840
    • Walaa albarry, DDS · Principal investigator
    Recruiting
07

References and documents

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. PubMed 38037213 ↗
  • 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. PubMed 30412347 ↗
  • 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. PubMed 40125556 ↗
  • 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. PubMed 15464564 ↗
  • 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. PubMed 29193632 ↗
  • 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. PubMed 36832213 ↗
  • 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. PubMed 6583388 ↗
  • Robbins JW. Differential diagnosis and treatment of excess gingival display. Pract Periodontics Aesthet Dent. 1999 Mar;11(2):265-72; quiz 273. PubMed 10321231 ↗

Individual participant data

Plan to share: No

08

Registry details

Key details

Study ID
NCT07532161
Lead sponsor
Damascus University
Responsible party
Sponsor
First posted
Apr 15, 2026
Start date
Apr 20, 2026
Primary completion
Jan 31, 2027 (estimated)
Completion
Jan 31, 2027 (estimated)
Last update
Apr 29, 2026

Study contacts

Tarek Qasem, DDS MSc PhD
Contact
Tarek2.qasem@damascusuniversity.edu.sy
+963 933432778
Walaa albarry, DDS
Contact
walaa9.albarry.@damascusuniversity.edu.sy
+963 996766302
Tarek Qasem, DDS MSc PhD
study director · Faculty of Dentistry, Damascus university, Syria.

Oversight

FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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