DiastemaNCT07778095
Diastema Closure and Stability: Clear Aligners vs Fixed Appliances With Laser Frenectomy
A study testing Clear Aligners, Fixed Orthodontic Appliance and Laser Frenectomy in people with Diastema and Generalized Interdental Spaces, run by Sana'a University.
Trial summary
This study is a prospective 2x2 factorial randomized clinical trial designed to evaluate and compare the closure efficiency and post-treatment stability of diastema associated with generalized interdental spacing (width >= 3 mm) treated with clear aligners versus fixed orthodontic appliances, with and without… Read more about this study
- Who is it for?
- Ages 18 to 35 years
- Conditions the study is for
- Diastema, Generalized Interdental Spaces
- What is being tested?
- Clear Aligners, Fixed Orthodontic Appliance and Laser Frenectomy
- Type of treatment
- Medical device, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- No sites listed yet
- Study dates
- Nov 2026to Jan 2029
- 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 35 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Adult patients aged 18 to 35 years.
- Presence of maxillary median diastema associated with generalized interdental spacing (width >= 3 mm).
- Fully erupted permanent teeth (excluding third molars).
- Good periodontal health with probing depths <= 3 mm and no bone loss.
- High motivation and commitment to follow treatment protocols and compliance.
- Written informed consent provided.
Who cannot join
- Previous orthodontic treatment.
- Severe skeletal malocclusion or craniofacial anomalies.
- Active periodontal disease, poor oral hygiene, or untreated caries.
- Missing or impacted permanent teeth in the maxillary arch (excluding third molars).
- Systemic diseases or long-term medication use affecting bone metabolism or tooth movement (e.g., bisphosphonates, systemic corticosteroids).
- Pregnant or lactating females.
- Heavy smokers or individuals with severe parafunctional
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Closure and Stability of Diastema Associated With Generalized Interdental Spacing Using Clear Aligners Versus Fixed Appliances With Adjunctive Frenectomy: A 2x2 Factorial RCT
This study is a prospective 2x2 factorial randomized clinical trial designed to evaluate and compare the closure efficiency and post-treatment stability of diastema associated with generalized interdental spacing (width >= 3 mm) treated with clear aligners versus fixed orthodontic appliances, with and without adjunctive laser frenectomy. Participants are randomized into four treatment arms to assess the main effects and interaction effects of appliance modality and laser frenectomy. Stability and relapse rates are systematically tracked across active treatment, a 6-month retention period, and post-retention follow-up intervals at 6 and 8 months.
Read the detailed description
Diastema associated with generalized interdental spacing (>= 3 mm) represents a challenging orthodontic condition with a heightened risk of post-treatment relapse. While fixed appliances provide reliable three-dimensional tooth movement control, clear aligners offer improved esthetics and patient comfort. Additionally, the role and timing of adjunctive laser frenectomy in stabilizing space closure remain controversial in generalized spacing cases.
This prospective 2x2 factorial randomized clinical trial is conducted at the Orthodontic Clinics, Faculty of Dentistry, Sana'a University, Yemen. A total of 48 eligible participants are randomly allocated into four equal groups (n=12 per group):
- Group 1: Clear Aligner Therapy with Adjunctive Laser Frenectomy
- Group 2: Clear Aligner Therapy without Frenectomy
- Group 3: Fixed Orthodontic Appliance with Adjunctive Laser Frenectomy
- Group 4: Fixed Orthodontic Appliance without Frenectomy
Treatment Protocols:
- Clear Aligner Group: Digital intraoral scans are obtained using a Zahndent scanner. Virtual treatment planning ensures sequential space closure with root control. Aligners are manufactured by Dentalign Company (Sana'a, Yemen) and worn 20-22 hours daily.
- Fixed Appliance Group: Treated using MBT prescription brackets with a 0.022-inch slot. The archwire sequence includes initial leveling with 0.012 to 0.018 NiTi wires, followed by rectangular stainless steel wires (0.016x0.022, 0.017x0.025, and 0.019x0.025 inches) for space closure and torque control.
- Auxiliary Mechanics: Cervical buttons are bonded in selected teeth across aligner and fixed groups to enhance bodily movement control.
- Adjunctive Laser Frenectomy: Performed using standardized laser technique following partial or complete space closure in designated groups.
Retention and Evaluation:
All participants follow a standardized retention protocol for 6 months post-treatment. Clinical, digital (Zahndent intraoral scanner), and radiographic (digital periapical sensor) assessments are conducted at five measurement time points:
- T0: Baseline (pre-treatment)
- T1: End of active orthodontic treatment
- T2: End of retention period (6 months)
- T3: 6 months post-retention
- T4: 8 months post-retention
The primary outcome is the amount of diastema relapse (mm). Secondary outcomes include total space closure, root parallelism, and relapse rates.
- Conditions
- Diastema, Generalized Interdental Spaces
- Being tested
- Clear Aligners, Fixed Orthodontic Appliance, Laser Frenectomy
- Keywords
- Diastema, Generalized Interdental Spacing, Clear Aligners, Fixed Orthodontic Appliances, Laser Frenectomy, Treatment Stability
- Medical subject headings
- Diastema
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Clear AlignersDevice
Custom thermoplastic aligners worn 20-22 hours daily with sequential staged movements for space closure.
Fixed Orthodontic ApplianceDevice
Metal brackets with MBT 0.022-inch slot prescription and sequential archwires for controlled space closure.
Laser FrenectomyProcedure or surgery
Surgical ablation and tissue excision of the labial frenum performed using a soft-tissue diode laser.
| Study group | Role | What they receive |
|---|---|---|
| Clear Aligners with Laser Frenectomy | Experimental | Participants receive clear aligner therapy for diastema and generalized space closure combined with adjunctive diode laser frenectomy. Receives: Device: Clear Aligners; Procedure: Laser Frenectomy |
| Clear Aligners without Laser Frenectomy | Experimental | Participants receive clear aligner therapy alone for diastema and generalized space closure without frenectomy. Receives: Device: Clear Aligners |
| Fixed Appliances with Laser Frenectomy | Active comparator | Participants receive conventional fixed orthodontic appliances (MBT 0.022-inch) combined with adjunctive diode laser frenectomy. Receives: Device: Fixed Orthodontic Appliance; Procedure: Laser Frenectomy |
| Fixed Appliances without Laser Frenectomy | Active comparator | Participants receive conventional fixed orthodontic appliances (MBT 0.022-inch) alone without frenectomy. Receives: Device: Fixed Orthodontic Appliance |
What is being measured
The primary outcome is the main question the study is designed to answer.
Amount of Diastema Relapse
Linear measurement (in millimeters) of maxillary median diastema relapse evaluated on digital 3D models (obtained via intraoral scanner) to measure space reopening post-treatment.
Measured: Baseline (0 months), 18 months, 24 months, 30 months, and 32 months
Secondary outcomes (3)
Rate and Efficiency of Diastema Closure
Total duration (months) to achieve complete space closure and the rate of space closure per month (mm/month) measured from digital 3D models.
Measured: Up to 18 months
Root Parallelism and Angulation Changes
Assessment of central incisor root parallelism and root position (bodily movement vs tipping) measured in degrees on digital periapical radiographs.
Measured: Baseline and 18 months
Labial Frenum Re-attachment Level
Linear measurement of labial frenum attachment level (in millimeters relative to the mucogingival junction).
Measured: Baseline, 18 months, and 32 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Aug 2026
- Study startNov 2026 (estimated)
- Primary completionDec 2028 (estimated)
- Study completionJan 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DiastemaStudies of the same condition, open and under way.
- 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
- Factorial
- Model description
- A 2x2 factorial randomized clinical trial evaluating two main factors: 1) Orthodontic appliance type (Clear Aligners vs Fixed Appliances) and 2) Adjunctive procedure (Laser Frenectomy vs No Frenectomy), yielding four distinct treatment groups.
- Masking
- None (open label)
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Sana'a University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Seham Abdulghani Hamood Alokam, Sana'a University
- Investigators
- Ghamdan A Al-Harazi, PhD, Study director, Sana'a University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07778095
- Sponsor's protocol ID
- PhD-SU-ORTHO-2026
- Status last verified
- Aug 2026
- First submitted
- 17 Aug 2026
- Last updated
- 21 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared to protect patient privacy and confidentiality. Aggregate study data and overall findings will be published in peer-reviewed scientific journals.
Study at a glance
From the registry record, last updated by the sponsor on 21 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Closure and Stability of Diastema Associated With Generalized Interdental Spacing Using Clear Aligners Versus Fixed Appliances With Adjunctive Frenectomy: A 2x2 Factorial RCT
- ClinicalTrials.gov ID
- NCT07778095
- Acronym / sponsor ID
- PhD-SU-ORTHO-2026
- Conditions
- Diastema, Generalized Interdental Spaces
- Keywords
- Diastema, Generalized Interdental Spacing, Clear Aligners, Fixed Orthodontic Appliances, Laser Frenectomy, Treatment Stability
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- Sana'a UniversityUniversity, hospital or other
- Study start
- Nov 2026 (estimated)
- Primary completion
- Dec 2028 (estimated)
- Study completion
- Jan 2029 (estimated)
- First posted
- 21 Aug 2026 (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.
This study is a prospective 2x2 factorial randomized clinical trial designed to evaluate and compare the closure efficiency and post-treatment stability of diastema associated with generalized interdental spacing (width >= 3 mm) treated with clear aligners versus fixed orthodontic appliances, with and without adjunctive laser frenectomy. Participants are randomized into four treatment arms to assess the main effects and interaction effects of appliance modality and laser frenectomy. Stability and relapse rates are systematically tracked across active treatment, a 6-month retention period, and post-retention follow-up intervals at 6 and 8 months.
Detailed description
Diastema associated with generalized interdental spacing (>= 3 mm) represents a challenging orthodontic condition with a heightened risk of post-treatment relapse. While fixed appliances provide reliable three-dimensional tooth movement control, clear aligners offer improved esthetics and patient comfort. Additionally, the role and timing of adjunctive laser frenectomy in stabilizing space closure remain controversial in generalized spacing cases.
This prospective 2x2 factorial randomized clinical trial is conducted at the Orthodontic Clinics, Faculty of Dentistry, Sana'a University, Yemen. A total of 48 eligible participants are randomly allocated into four equal groups (n=12 per group):
- Group 1: Clear Aligner Therapy with Adjunctive Laser Frenectomy
- Group 2: Clear Aligner Therapy without Frenectomy
- Group 3: Fixed Orthodontic Appliance with Adjunctive Laser Frenectomy
- Group 4: Fixed Orthodontic Appliance without Frenectomy
Treatment Protocols:
- Clear Aligner Group: Digital intraoral scans are obtained using a Zahndent scanner. Virtual treatment planning ensures sequential space closure with root control. Aligners are manufactured by Dentalign Company (Sana'a, Yemen) and worn 20-22 hours daily.
- Fixed Appliance Group: Treated using MBT prescription brackets with a 0.022-inch slot. The archwire sequence includes initial leveling with 0.012 to 0.018 NiTi wires, followed by rectangular stainless steel wires (0.016x0.022, 0.017x0.025, and 0.019x0.025 inches) for space closure and torque control.
- Auxiliary Mechanics: Cervical buttons are bonded in selected teeth across aligner and fixed groups to enhance bodily movement control.
- Adjunctive Laser Frenectomy: Performed using standardized laser technique following partial or complete space closure in designated groups.
Retention and Evaluation:
All participants follow a standardized retention protocol for 6 months post-treatment. Clinical, digital (Zahndent intraoral scanner), and radiographic (digital periapical sensor) assessments are conducted at five measurement time points:
- T0: Baseline (pre-treatment)
- T1: End of active orthodontic treatment
- T2: End of retention period (6 months)
- T3: 6 months post-retention
- T4: 8 months post-retention
The primary outcome is the amount of diastema relapse (mm). Secondary outcomes include total space closure, root parallelism, and relapse rates.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Factorial
- Masking
- None (open label)
- Number of arms
- 4
- Model description
- A 2x2 factorial randomized clinical trial evaluating two main factors: 1) Orthodontic appliance type (Clear Aligners vs Fixed Appliances) and 2) Adjunctive procedure (Laser Frenectomy vs No Frenectomy), yielding four distinct treatment groups.
| Arm | Type | Receives |
|---|---|---|
| Clear Aligners with Laser Frenectomy | Experimental | Device: Clear Aligners, Procedure: Laser FrenectomyParticipants receive clear aligner therapy for diastema and generalized space closure combined with adjunctive diode laser frenectomy. |
| Clear Aligners without Laser Frenectomy | Experimental | Device: Clear AlignersParticipants receive clear aligner therapy alone for diastema and generalized space closure without frenectomy. |
| Fixed Appliances with Laser Frenectomy | Active comparator | Device: Fixed Orthodontic Appliance, Procedure: Laser FrenectomyParticipants receive conventional fixed orthodontic appliances (MBT 0.022-inch) combined with adjunctive diode laser frenectomy. |
| Fixed Appliances without Laser Frenectomy | Active comparator | Device: Fixed Orthodontic ApplianceParticipants receive conventional fixed orthodontic appliances (MBT 0.022-inch) alone without frenectomy. |
Who may qualify
- Ages
- 18 to 35 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Adult patients aged 18 to 35 years.
- Presence of maxillary median diastema associated with generalized interdental spacing (width >= 3 mm).
- Fully erupted permanent teeth (excluding third molars).
- Good periodontal health with probing depths <= 3 mm and no bone loss.
- High motivation and commitment to follow treatment protocols and compliance.
Key exclusion criteria (7 listed)
- Previous orthodontic treatment.
- Severe skeletal malocclusion or craniofacial anomalies.
- Active periodontal disease, poor oral hygiene, or untreated caries.
- Missing or impacted permanent teeth in the maxillary arch (excluding third molars).
- Systemic diseases or long-term medication use affecting bone metabolism or tooth movement (e.g., bisphosphonates, systemic corticosteroids).
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 |
|---|---|---|
| Clear AlignersCustom thermoplastic aligners worn 20-22 hours daily with sequential staged movements for space closure. | Device | Clear Aligners with Laser Frenectomy, Clear Aligners without Laser Frenectomy |
| Fixed Orthodontic ApplianceMetal brackets with MBT 0.022-inch slot prescription and sequential archwires for controlled space closure. | Device | Fixed Appliances with Laser Frenectomy, Fixed Appliances without Laser Frenectomy |
| Laser FrenectomySurgical ablation and tissue excision of the labial frenum performed using a soft-tissue diode laser. | Procedure or surgery | Clear Aligners with Laser Frenectomy, Fixed Appliances with Laser Frenectomy |
Primary outcome
Amount of Diastema Relapse
Time frame: Baseline (0 months), 18 months, 24 months, 30 months, and 32 months
Linear measurement (in millimeters) of maxillary median diastema relapse evaluated on digital 3D models (obtained via intraoral scanner) to measure space reopening post-treatment.
3 secondary outcomes
Rate and Efficiency of Diastema Closure
Time frame: Up to 18 months
Root Parallelism and Angulation Changes
Time frame: Baseline and 18 months
Labial Frenum Re-attachment Level
Time frame: Baseline, 18 months, and 32 months
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 21 Aug 2026.
- Individual participant dataSharing planned: No. Individual participant data will not be shared to protect patient privacy and confidentiality. Aggregate study data and overall findings will be published in peer-reviewed scientific journals.
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.
Ghamdan A Al-Harazi, PhD study director
Sana'a University
Questions about this trial
What is this clinical trial studying?
A study testing Clear Aligners, Fixed Orthodontic Appliance and Laser Frenectomy in people with Diastema and Generalized Interdental Spaces, run by Sana'a University.
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 6 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 21 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
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 Seham Abdulghani Hamood Alokam, BDS, MSc (00967738718234, SEHAM.AL_OKAM@su.edu.ye), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Amount of Diastema Relapse (time frame: Baseline (0 months), 18 months, 24 months, 30 months, and 32 months). 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 21 Aug 2026; AzTrials last refreshed its copy on 5 Nov 2026.