An interventional study of Clear Aligners and Fixed Orthodontic Appliance in Diastema and Generalized Interdental Spaces, sponsored by Sana'a University. Not yet recruiting. Open to participants aged 18 Years to 35 Years. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Sana'a University · Not applicable, Interventional, and Treatment
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.
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):
Treatment Protocols:
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:
The primary outcome is the amount of diastema relapse (mm). Secondary outcomes include total space closure, root parallelism, and relapse rates.
Exclusion Criteria:
Participants receive clear aligner therapy for diastema and generalized space closure combined with adjunctive diode laser frenectomy.
Device: Clear Aligners · Procedure: Laser Frenectomy
Participants receive clear aligner therapy alone for diastema and generalized space closure without frenectomy.
Device: Clear Aligners
Participants receive conventional fixed orthodontic appliances (MBT 0.022-inch) combined with adjunctive diode laser frenectomy.
Device: Fixed Orthodontic Appliance · Procedure: Laser Frenectomy
Participants receive conventional fixed orthodontic appliances (MBT 0.022-inch) alone without frenectomy.
Device: Fixed Orthodontic Appliance
Custom thermoplastic aligners worn 20-22 hours daily with sequential staged movements for space closure.
Metal brackets with MBT 0.022-inch slot prescription and sequential archwires for controlled space closure.
Surgical ablation and tissue excision of the labial frenum performed using a soft-tissue diode laser.
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.
Time frame: Baseline (0 months), 18 months, 24 months, 30 months, and 32 months
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.
Time frame: 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.
Time frame: Baseline and 18 months
Labial Frenum Re-attachment Level
Linear measurement of labial frenum attachment level (in millimeters relative to the mucogingival junction).
Time frame: Baseline, 18 months, and 32 months
No study locations are listed for this record.
Plan to share: 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.
No publications or documents are linked to this record.
This study is not yet recruiting, as verified in Aug 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Diastema
Sana'a University