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Clinical Comparison of Clear Aligners and Fixed Appliances in Dental Anterior Open Bite

Clinical Comparison of Clear Aligners and Fixed Orthodontic Appliances in the Treatment of Dental Anterior Open Bite in Adults: A Randomized Controlled Clinical Trial

Status
Not yet recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07778108
Enrollment
46
Registered
2026-08-21
Start date
2026-11-01
Completion date
2029-07-01
Last updated
2026-08-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Open Bite, Malocclusion Class I

Keywords

Anterior Open Bite, Clear Aligners, Fixed Orthodontic Appliances, Randomized Controlled Clinical Trial, Orthodontic Stability

Brief summary

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.

Detailed description

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.

Interventions

DEVICEIn-House Clear Aligners

Thermoplastic clear aligners (PETG 0.75-0.8 mm) manufactured in-house for vertical open bite closure, combined with composite attachments and intermaxillary elastics.

Conventional 0.022-inch MBT prescription fixed brackets utilizing two-segment arch mechanics and intermaxillary vertical elastics.

Sponsors

Sana'a University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
No

Inclusion criteria

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

* Previous orthodontic treatment. Presence of craniofacial anomalies or cleft lip/palate. Active periodontal disease or severe bone loss. History of temporomandibular joint disorders (TMD). Systemic conditions or medications affecting bone metabolism and tooth movement.

Design outcomes

Primary

MeasureTime frameDescription
Overbite ChangeBaseline (T0) and completion of active treatment (T1, approximately 12-18 months)Changes in anterior vertical overlap measured in millimeters on 3D digital dental models from baseline to the end of active treatment.

Secondary

MeasureTime frameDescription
Cephalometric Dental ChangesBaseline and through study completion, an average of 18 monthsChanges in upper and lower incisor inclinations (U1-SN and L1-MP angles, measured in degrees) evaluated on lateral cephalometric radiographs.
Cephalometric Skeletal ChangesBaseline and through study completion, an average of 18 monthsChanges in vertical and sagittal skeletal relationships (SN-GoGn angle, measured in degrees) evaluated on lateral cephalometric radiographs.

Contacts

CONTACTOthman Ahmed Othman Ali, BDS, MSc
othman.othman@su.edu.ye00967738718234
PRINCIPAL_INVESTIGATORGhamdan Al-Harazi, PhD

Sana'a University

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Aug 22, 2026