An interventional study of In-House Clear Aligners and Fixed Orthodontic Appliances in Open Bite and Malocclusion Class I, sponsored by Sana'a University. Not yet recruiting. Open to participants aged 18 Years to 30 Years. Per ClinicalTrials.gov, last updated 2026-08-21.
Sponsored by Sana'a University · Not applicable, Interventional, and Treatment
Dental anterior open bite is a challenging orthodontic condition with a high risk of relapse in adults. This randomized controlled clinical trial aims to compare the effectiveness and post-treatment stability of in-house clear aligners versus fixed orthodontic appliances in treating adult patients aged 18-30 years with dental anterior open bite (0 to -4 mm).
A total of 46 eligible participants will be randomly allocated into two equal groups (23 treated with clear aligners and 23 with fixed appliances). Treatment outcomes, vertical dentoalveolar changes, and skeletal changes will be evaluated using digital intraoral scans, virtual model superimposition, and lateral cephalometric analysis. Following active treatment, an 8-month retention phase (bonded lingual retainer combined with a vacuum-formed retainer) and an 8-month post-retention follow-up phase will be implemented to comprehensively evaluate treatment stability and relapse tendency over a total observation period of 16 months.
Anterior open bite (AOB) in adults presents significant treatment challenges due to the absence of remaining growth and a high relapse tendency. While fixed orthodontic appliances remain the standard approach for vertical control, clear aligner therapy has gained popularity despite limited randomized controlled evidence regarding its long-term predictability and stability.
This study is designed as a single-center, parallel-group, randomized controlled clinical trial conducted at the Faculty of Dentistry, Sana'a University. Enrolled participants meet strict inclusion criteria: adult age (18-30 years), dental anterior open bite (0 to -4 mm), Class I malocclusion with normal molar relationships, non-extraction treatment requirements (crowding/spacing \le 4\text{ mm}), and good oral hygiene.
Participants in the Clear Aligner group receive fully digital in-house aligners fabricated using Zahndent intraoral scans, 3D Maestro setup software, Elegoo Saturn 4 Ultra 16K printing, and PETG thermoforming sheets (0.75-0.8 mm). Aligner mechanics include optimized attachments and medium power intermaxillary elastics (3-4.5 oz) worn 20-22 hours per day. Participants in the Fixed Appliance group are treated using 0.022-inch MBT prescription brackets with a two-segment arch mechanics approach (canine-to-canine anterior segment and premolar/molar posterior segment) combined with progressive wire sequencing and vertical elastics.
Primary and secondary outcomes-including overbite increase, cephalometric vertical changes, treatment efficiency, patient compliance, and satisfaction-will be recorded at baseline, post-treatment, after 8 months of retention, and after 8 months of post-retention follow-up.
34 studies on the registry are indexed under Open Bite; 8 are open to participants now.
This study's planned enrollment of 46 is above the median of 30 across 28 interventional studies indexed under Open Bite.
Browse Open Bite studies →Sana'a University is the lead sponsor of 27 studies on the registry; 15 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Adult patients aged 18 to 30 years with fully erupted permanent dentition. Anterior open bite equal to or greater than 2 mm. Angle Class I malocclusion. Good oral hygiene and healthy periodontal status.
-
Exclusion Criteria:
Participants receive in-house manufactured PETG clear aligners (0.75-0.8 mm) designed with 3D Maestro setup software and printed using Elegoo Saturn 4 Ultra 16K. Aligners are changed every 10-14 days, combined with optimized composite attachments and medium power intermaxillary vertical elastics (3-4.5 oz) worn 20-22 hours daily.
Device: In-House Clear Aligners
Participants receive conventional fixed orthodontic appliances with 0.022-inch MBT prescription brackets. Treatment utilizes a two-segment arch mechanics approach (canine-to-canine anterior segment and premolar/molar posterior segment) combined with progressive wire sequencing and intermaxillary vertical elastics.
Device: Fixed Orthodontic Appliances
Thermoplastic clear aligners (PETG 0.75-0.8 mm) manufactured in-house for vertical open bite closure, combined with composite attachments and intermaxillary elastics.
Also known as: PETG Aligners
Conventional 0.022-inch MBT prescription fixed brackets utilizing two-segment arch mechanics and intermaxillary vertical elastics.
Overbite Change
Changes in anterior vertical overlap measured in millimeters on 3D digital dental models from baseline to the end of active treatment.
Time frame: Baseline (T0) and completion of active treatment (T1, approximately 12-18 months)
Cephalometric Skeletal Changes
Changes in vertical and sagittal skeletal relationships (SN-GoGn angle, measured in degrees) evaluated on lateral cephalometric radiographs.
Time frame: Baseline and through study completion, an average of 18 months
Cephalometric Dental Changes
Changes in upper and lower incisor inclinations (U1-SN and L1-MP angles, measured in degrees) evaluated on lateral cephalometric radiographs.
Time frame: Baseline and through study completion, an average of 18 months
No study locations are listed for this record.
Plan to share: No — Individual participant data will not be shared to protect participant privacy and confidentiality.
No publications or documents are linked to this record.
Start is estimated for Nov 2026; primary completion for Mar 2028, 16 months later.
Of 24 interventional studies with no phase under Open Bite, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 36. This study's planned 16 months is close to that.
How these figures are worked out, and which studies are left out of them.
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.
Sana'a University