Comparison Between Clear Aligners and Traditional Fixed Appliances in the Treatment of Four-premolar-extraction Cases

Study Overview
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Brief Summary
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Patients who have severe crowding that require four premolars extraction will be treated in this study. The efficacy of the clear aligners and vestibular fixed appliances will be assessed. The treatment result of these two different methods will be explored using the Peer Assessment Rating (PAR) in two different times (T0: Before treatment, T1: After treatment) and the American Board of Orthodontics Objective Grading System (ABO-OGS) after treatment (T1). There are two groups: First group (Experimental): the patients in this group will be treated using clear aligners. Second group (Control): the patients in this group will be treated using fixed appliances.

Detailed Description
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For years, orthodontists and dentists have used removable appliances for orthodontic treatment. Today, with the CAD/CAM technology, clear aligners treat a broader range of cases with greater precision. They consist of a series of plastic aligners that are intended to replace conventional wire and bracket technology for many orthodontic cases. Each custom manufactured aligner exerts gentle, continuous forces to move teeth incrementally from their original state to a final, treated state. Each aligner is worn for about two weeks, then replaced by the next in the series until the final position is achieved.

Official Title
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Evaluation of the Efficacy of Clear Aligners in the Correction of Severe Dental Crowding Cases Combined With Premolar Extraction Versus Vestibular Fixed Orthodontic Appliances: A Randomized Clinical Controlled Trial

Conditions
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Malocclusion, Angle Class I, Malocclusion; Displaced or Missing Teeth, Crowding

Intervention / Treatment
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* Device: Fixed Appliances
* Device: Clear Aligners


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Class I malocclusion with severe crowding (more than 5 mm of tooth-size-arch-length-discrepancy). Good oral hygiene and periodontal health. No severe skeletal discrepancy. Normal proclination for the upper and lower incisors. No congenitally missing or extracted teeth (except for the third molars). No history of previous trauma to the maxillofacial region or surgical interventions. Exclusion Criteria: Bimaxillary dentoalveolar severe protrusion. Previous orthodontic treatment. Subject with psychological abnormalities. Subject with systemic diseases. Subject has known allergy to latex and plastic

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 25 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: fixed appliances<br>patients will be treated using fixed appliances in order to align their teeth after extraction of four premolars | Device: Fixed Appliances<br>* Using an MBT-prescription of metallic brackets, patients will be treated in the conventional way<br>|
| Experimental: clear aligners<br>patients will be treated using clear aligners in order to align their teeth after extraction of four premolars | Device: Clear Aligners<br>* Using a sequence of clear aligners, patients will be give an aligner every two weeks until the completion of treatment<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in the American Board of Orthodontics - Objective Grading System (ABO-OGS) | Eight domains are evaluated: Alignment: No more than 2 points shall be subtracted for any tooth when it is poorly aligned; Marginal Ridges: The total number of deductions shall be subtracted from 32 to give the score for this domain; Buccolingual inclination: If the mandibular lingual cusps or maxillary buccal cusps are more than 1 mm from the straight edge surface, 1 point shall be subtracted for that tooth; Occlusal Contacts: If a cusp is out of contact with the opposing arch, 1 point is subtracted for that tooth; Occlusal relationships. The total number of deductions are subtracted from 24 to give the score for occlusal relationships; Overjet; Interproximal contacts. If no interproximal spaces exist, then no points are subtracted; and Root angulation: Any deviations in roots' angulations will cause a deduction form the general score. Finally, a case that loses more than 30 points will be considered a failure. A case that loses less than 20 points will be considered acceptable. | T1: one day before the commencement of treatment. T2: one day following the end of treatment (that is expected to happen within 24 months) |