Gummy Smile Due to Hypermobile Upper LipNCT06952218
Effect of Cross-linked Hyaluronic Acid Filler Versus Botulinum Toxin Type A (Botox) in Management of Gummy Smile
A study testing Injection of cross linked hyaluronic acid filler in people with Gummy Smile Due to Hypermobile Upper Lip, run by Cairo University at 2 sites in Egypt.
Trial summary
A smile is supposed to express one's feelings and expressions, for that there has been an awakening concern for the appearance of gummy smile. Gummy smile is the appearance of about 2mm or more of the gingiva during smiling. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Gummy Smile Due to Hypermobile Upper Lip
- What is being tested?
- Injection of cross linked hyaluronic acid filler
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 34 participants
- Where
- 2 sitesEgypt
- Study dates
- 1 Dec 2025to 1 Dec 2025
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Patients with excessive gingival display ranging from 3-8mm due to hypermobile lip.
- Age ranges from 18 years or above.
Who cannot join
- Excessive gingival display due to other etiological factors.
- Patients allergic to botox or hyaluronic acid fillers.
- Patients with any medical condition that contraindicates botox or hyaluronic acid filler injection.
- Patients previously injected with permanent fillers.
- Pregnancy.
- Breastfeeding females.
- Patients with active inflammatory or infectious disease at intended site of injection.
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Effect of Cross-linked Hyaluronic Acid Filler Versus Botulinum Toxin Type A (Botox) in Management of Gummy Smile: Randomized Controlled Clinical Trial
A smile is supposed to express one's feelings and expressions, for that there has been an awakening concern for the appearance of gummy smile. Gummy smile is the appearance of about 2mm or more of the gingiva during smiling. It may affect the quality of life of individuals affecting their self-esteem; patients desire to look good not only while resting but while dynamically expressing themselves too. Variable factors contribute to this gingival display whether skeletal, dental or muscular. Variable treatment modalities are done solely or in adjunction to each other for the treatment of gummy smile including both surgical or nonsurgical procedures.
Read the detailed description
In patients not preferring surgical correction of gummy smile, botulinum toxin injection type A can be a helpful solution for reduction of peri-oral muscular hypermobility. A characteristic feature of botulinum toxin is the need for the re-injection in short intervals of time to yield better lasting effects. The use of cross-linked hyaluronic acid dermal fillers when used to myomodulate the peri-oral muscles give more immediate results and reduces the need for re-injection at shorter intervals.
Botulinum toxin type A, a toxin produced by the bacteria Clostridium botulinum, has been widely used in different therapeutic and cosmetic applications in dentistry. Amongst its important applications is the treatment of gummy smile by reducing the hypermobility of the peri-oral muscles through chemical denervation. Botox elicits temporary results and requires re-injection at certain time points. It is a safe, suitable, transient solution for patients not willing to undergo any surgical intervention to manage their gummy smile. Another approach for the non invasive treatment of muscular hypermobility is the injection of cross linked hyaluronic acid filler. Once the filler is injected, it typically occupies space that lessens the muscle movement limiting its hypermobility. Instant Smile enhancement is observed upon injection of cross-linked hyaluronic acid fillers and no need to repeat the injection at closer periods of time. Hyaluronic acid fillers are non-permanent fillers that are degradable by hyaluronidase and cross linking renders them more resistant to enzymatic degradation thus lasting longer.
- Conditions
- Gummy Smile Due to Hypermobile Upper Lip
- Being tested
- Injection of cross linked hyaluronic acid filler
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Injection of cross linked hyaluronic acid fillerProcedure or surgery
Injection of cross linked hyaluronic acid filler
| Study group | Role | What they receive |
|---|---|---|
| Group I will receive botulinum toxin type A injection. | Active comparator | Injection site will be determined at a point in which the elevator muscles of the upper lip which are levator labii superioris, levator labii superioris alaeque nasi, and zygomaticus minor converge into the lateral area of the ala of the nose. The center of intersection of the mentioned muscles is termed Yonsei Point and estimated to be at a 1cm horizontal distance from the ala of the nose and a 3cm vertical distance from the lip line. Lidocaine 5% ointment will be applied to the intended injection site for 20 mins. In control group, 2.5 units of botulinum toxin will be injected bilaterally at Yonsei Point. An insulin needle will be used for injecting the botox. Receives: Procedure: Injection of cross linked hyaluronic acid filler |
| Group II will receive cross linked hyaluronic acid filler injection | Experimental | Lidocaine 5% ointment will be applied to the intended injection site for 20 mins. In intervention group, a bolus of 0.2 ml of 20% cross linked hyaluronic acid filler will be injected in canine fossa region using a 29G needle preceeded by aspiration for 10 seconds ensuring no blood vessel will be involved. Receives: Procedure: Injection of cross linked hyaluronic acid filler |
What is being measured
The primary outcome is the main question the study is designed to answer.
Gingival display
will be measured from a point denoting the lowest margin of the upper lip perpendicular and superior to the midportion of the gingival margin of the maxillary lateral incisor to the gingival margin at the midpoint of the maxillary lateral incisor.
The midpoint of the incisal edge of the maxillary lateral incisor will be used as a reference point if the upper lip fell below the gingival margin of the same tooth post-injection (Diaspro, Cavallini et al. 2018).
Measured: week 2, month 1, month 3, month 6, month 9
Secondary outcomes (3)
Patient satisfaction
The patient will be asked to rate the satisfaction about her/his smile on a scale from 1 to 5 where 1 represents the least satisfied and 5 indicates the most (Makkeiah, Harfoush et al. 2021).
Measured: week 2, month 1, month 3, month 6, month 9
Postoperative pain
The patient will be asked to mark her/his current level of pain on a scale of 10 cm line denoting a range between zero being (no pain) to 10 (maximum pain) (Diaspro, Cavallini et al. 2018).
Measured: week 2, month 1, month 3, month 6, month 9
Lip mobility
will be measured by subtracting upper lip length during smiling from upper lip length at rest (Sabbah 2022). The upper lip length is measured from the subnasale to the lower border of the upper lip at the central incisors' region at smile and rest (Ali, Kilani et al. 2023).
Measured: week 2, month 1, month 3, month 6, month 9
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Apr 2025
- Study start1 Dec 2025 (estimated)
- Primary completion1 Dec 2025 (estimated)
- Study completion1 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Gummy Smile Due to Hypermobile Upper LipStudies of the same condition, open and under way.
- More trials run by Cairo UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Lidocaine 5% ointment will be applied to the intended injection site for 20 mins. In control group, 2.5 units of botulinum toxin will be injected bilaterally at Yonsei Point. An insulin needle will be used for injecting the botox. In intervention group, a bolus of 0.2 ml of 20% cross linked hyaluronic acid filler will be injected in canine fossa region using a 29G needle preceeded by aspiration for 10 seconds ensuring no blood vessel will be involved. The product will be infiltrated slowly keeping an angle of 90 degrees in relation to the bone.
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 34 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cairo University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Raghda Hussein Metwaly Mahmoud, Cairo University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06952218
- Sponsor's protocol ID
- 5699269
- Status last verified
- Apr 2025
- First submitted
- 15 Apr 2025
- Last updated
- 30 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Cross-linked Hyaluronic Acid Filler Versus Botulinum Toxin Type A (Botox) in Management of Gummy Smile: Randomized Controlled Clinical Trial
- ClinicalTrials.gov ID
- NCT06952218
- Acronym / sponsor ID
- 5699269
- Conditions
- Gummy Smile Due to Hypermobile Upper Lip
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 34 participants (estimated)
- Lead sponsor
- Cairo UniversityUniversity, hospital or other
- Study start
- 1 Dec 2025 (estimated)
- Primary completion
- 1 Dec 2025 (estimated)
- Study completion
- 1 Dec 2025 (estimated)
- First posted
- 30 Apr 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A smile is supposed to express one's feelings and expressions, for that there has been an awakening concern for the appearance of gummy smile. Gummy smile is the appearance of about 2mm or more of the gingiva during smiling. It may affect the quality of life of individuals affecting their self-esteem; patients desire to look good not only while resting but while dynamically expressing themselves too. Variable factors contribute to this gingival display whether skeletal, dental or muscular. Variable treatment modalities are done solely or in adjunction to each other for the treatment of gummy smile including both surgical or nonsurgical procedures.
Detailed description
In patients not preferring surgical correction of gummy smile, botulinum toxin injection type A can be a helpful solution for reduction of peri-oral muscular hypermobility. A characteristic feature of botulinum toxin is the need for the re-injection in short intervals of time to yield better lasting effects. The use of cross-linked hyaluronic acid dermal fillers when used to myomodulate the peri-oral muscles give more immediate results and reduces the need for re-injection at shorter intervals.
Botulinum toxin type A, a toxin produced by the bacteria Clostridium botulinum, has been widely used in different therapeutic and cosmetic applications in dentistry. Amongst its important applications is the treatment of gummy smile by reducing the hypermobility of the peri-oral muscles through chemical denervation. Botox elicits temporary results and requires re-injection at certain time points. It is a safe, suitable, transient solution for patients not willing to undergo any surgical intervention to manage their gummy smile. Another approach for the non invasive treatment of muscular hypermobility is the injection of cross linked hyaluronic acid filler. Once the filler is injected, it typically occupies space that lessens the muscle movement limiting its hypermobility. Instant Smile enhancement is observed upon injection of cross-linked hyaluronic acid fillers and no need to repeat the injection at closer periods of time. Hyaluronic acid fillers are non-permanent fillers that are degradable by hyaluronidase and cross linking renders them more resistant to enzymatic degradation thus lasting longer.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Lidocaine 5% ointment will be applied to the intended injection site for 20 mins. In control group, 2.5 units of botulinum toxin will be injected bilaterally at Yonsei Point. An insulin needle will be used for injecting the botox. In intervention group, a bolus of 0.2 ml of 20% cross linked hyaluronic acid filler will be injected in canine fossa region using a 29G needle preceeded by aspiration for 10 seconds ensuring no blood vessel will be involved. The product will be infiltrated slowly keeping an angle of 90 degrees in relation to the bone.
| Arm | Type | Receives |
|---|---|---|
| Group I will receive botulinum toxin type A injection. | Active comparator | Procedure: Injection of cross linked hyaluronic acid fillerInjection site will be determined at a point in which the elevator muscles of the upper lip which are levator labii superioris, levator labii superioris alaeque nasi, and zygomaticus minor converge into the lateral area of the ala of the nose. The center of intersection of the mentioned muscles is termed Yonsei Point and estimated to be at a 1cm horizontal distance from the ala of the nose and a 3cm vertical distance from the lip line. Lidocaine 5% ointment will be applied to the intended injection site for 20 mins. In control group, 2.5 units of botulinum toxin will be injected bilaterally at Yonsei Point. An insulin needle will be used for injecting the botox. |
| Group II will receive cross linked hyaluronic acid filler injection | Experimental | Procedure: Injection of cross linked hyaluronic acid fillerLidocaine 5% ointment will be applied to the intended injection site for 20 mins. In intervention group, a bolus of 0.2 ml of 20% cross linked hyaluronic acid filler will be injected in canine fossa region using a 29G needle preceeded by aspiration for 10 seconds ensuring no blood vessel will be involved. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (2 listed)
- Patients with excessive gingival display ranging from 3-8mm due to hypermobile lip.
- Age ranges from 18 years or above.
Key exclusion criteria (7 listed)
- Excessive gingival display due to other etiological factors.
- Patients allergic to botox or hyaluronic acid fillers.
- Patients with any medical condition that contraindicates botox or hyaluronic acid filler injection.
- Patients previously injected with permanent fillers.
- Pregnancy.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Injection of cross linked hyaluronic acid fillerInjection of cross linked hyaluronic acid filler | Procedure or surgery | Group I will receive botulinum toxin type A injection., Group II will receive cross linked hyaluronic acid filler injection |
Primary outcome
Gingival display
Time frame: week 2, month 1, month 3, month 6, month 9
will be measured from a point denoting the lowest margin of the upper lip perpendicular and superior to the midportion of the gingival margin of the maxillary lateral incisor to the gingival margin at the midpoint of the maxillary lateral incisor. The midpoint of the incisal edge of the maxillary lateral incisor will be used as a reference point if the upper lip fell below the gingival margin of the same tooth post-injection (Diaspro, Cavallini et al. 2018).
3 secondary outcomes
Patient satisfaction
Time frame: week 2, month 1, month 3, month 6, month 9
Postoperative pain
Time frame: week 2, month 1, month 3, month 6, month 9
Lip mobility
Time frame: week 2, month 1, month 3, month 6, month 9
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Apr 2025.
- Individual participant dataSharing planned: No
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Injection of cross linked hyaluronic acid filler in people with Gummy Smile Due to Hypermobile Upper Lip, run by Cairo University at 2 sites in Egypt.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 30 Apr 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Egypt. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Raghda Hussein (01122642622, raghda.metwaly@dentistry.cu.edu.eg), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Gingival display (time frame: week 2, month 1, month 3, month 6, month 9). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Apr 2025.