An interventional study of Clear aligner therapy and Fixed pre-adjusted edgewise orthodontic appliance in Crowding of Anterior Mandibular Teeth, sponsored by University of Sharjah. Enrolling by invitation at 1 site in United Arab Emirates. Open to participants aged 16 Years to 45 Years. Per ClinicalTrials.gov, last updated 2026-08-11.
Sponsored by University of Sharjah · Not applicable, Interventional, and Treatment
The goal of this clinical trial is to compare between fixed labial braces and clear aligners for the straightening of moderately overlapped lower front teeth. The main questions it aims to answer are:
Participants will:
The study is a randomized controlled trial aimed at comparing the efficiency, efficacy, periodontal and occlusal outcomes between two orthodontic treatment options: clear aligners and traditional fixed braces for patients with moderate crowding in the lower incisors.
Pre-treatment diagnostic records including clinical examination, intraoral scans, intraoral and extraoral photographs will be obtained for each participant.
To ensure that participants in both groups have similar levels of crowding severity and comparable dental health characteristics at the start of the study, randomization will be conducted in blocks. A total of forty participants (20 in each group) will be selected according to specific criteria designed to maintain this uniformity across both treatment groups.This study follows a parallel-group design and the participants will be randomly allocated into one of the two groups included in the study:
Intervention Groups:
Primary Outcomes:
Secondary Outcomes:
Data will be analyzed using SPSS (Statistical Package for the Social Sciences) software, with statistical tests appropriate to the variable types (e.g., Mann-Whitney for group comparisons and Wilcoxon Signed-Rank test for time-related variables).
88 studies on the registry are indexed under Crowding; 22 are open to participants now.
This study's planned enrollment of 40 is above the median of 36 across 74 interventional studies indexed under Crowding.
Browse Crowding studies →University of Sharjah is the lead sponsor of 42 studies on the registry; 17 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.
Exclusion Criteria:
Participants in this group will be treated with pre-adjusted fixed orthodontic appliances.
Device: Fixed pre-adjusted edgewise orthodontic appliance
Participants in this group will receive clear aligners customized based on a digital model of each patient's dentition.
Device: Clear aligner therapy
Participants in this group will receive clear aligners (EON Aligner, Minneapolis), designed and customized based on a digital model of each patient's dental structure. Aligners will be worn for at least 22 hours daily, and patients will change to a new aligner depending on treatment progress.
Also known as: Clear aligners, Clear aligner therapy (CAT), Eon aligner
Participants in this group will be treated with pre-adjusted fixed orthodontic appliances (Master Series®, American Orthodontics™, WI, USA). This system includes fixed brackets bonded on the labial surface of teeth and a sequence of progressively larger arch wires aimed at achieving alignment over time.
Also known as: Fixed orthodontic appliance, Fixed labial braces, Conventional braces, Edgewise appliance, Fixed Appliance, Pre-adjusted Appliance, Straight-wire Appliance, Fixed Braces, Fixed Orthodontic Braces, Pre-adjusted Edgewise Bracket System, Straight-wire Bracket System, Fixed Multibracket Appliance, Fixed Straight-wire Technique
Total alignment time
The duration of treatment time (rounded to the nearest day) required to achieve full alignment of the mandibular incisors determined clinically as \<1mm little's irregularity index, evaluated for both treatment groups. This information is to be extracted from participant notes into a data collection sheet designed specifically for this study.
Time frame: Through alignment, an average of 6 months
Bleeding on probing
Bleeding on probing as an indicator of tissue inflammatory response to bacterial pathogensis, using the Michigan Williams probe assigned a score of 0 - 3 for each site.
Time frame: Baseline, after 3 months, and after 6 months
Occlusal contact surface area
Occlusal contact surface area as measured by the T-scan device in terms of no. of pixels
Time frame: Baseline, and after an average of 6 months, and after treatment an average of 1 year
Efficacy of clear aligners Vs fixed appliances in alignment of lower anterior teeth
Efficacy of clear aligners Vs fixed appliances in alignment of lower anterior teeth using Little's irregularity index
Time frame: Baseline, and after an average of 6 months
Symmetry of contact distribution
Symmetry of contact distribution as measured by the T-scan device.
Time frame: Baseline, and after an average of 6 months
Probing depth
The distance measured from the base of the pocket to the most apical point on the gingival margin using the Michigan Williams probe.
Time frame: Baseline, after 3 months, and after 6 months
Plaque index
Plaque index to evaluate the level and rate of plaque formation on tooth surfaces
Time frame: Baseline, after 3 months, and after 6 months
Gingival index
Gingival index to determine the severity of gingival inflammation with a score from 0 - 3
Time frame: Baseline, after 3 months, and after 6 months
Total treatment time
The duration of treatment time (rounded to the nearest day) required to complete treatment, evaluated for both treatment groups. This information is to be extracted from participant notes into a data collection sheet designed specifically for this study.
Time frame: Through treatment, an average of 1 year
Total number of scheduled routine appointments and additional emergency visits
The number of scheduled routine appointments required to achieve full mandibular incisor alignment and additional visits for emergencies as recorded in participants' notes and the data collection sheet.
Time frame: Through alignment, an average of 6 months
Missed appointment rate
The number of scheduled routine appointments that the patient failed to attend during the alignment phase of treatment as recorded in both participants' notes and the data collection sheet.
Time frame: Through alignment, an average of 6 months
Number of refinements
If any of the participants required a refinement scan prior to completion of leveling and alignment of the mandibular incisors, this would be recorded in both participants' notes and the data collection sheet
Time frame: Through alignment, an average of 6 months
Bracket/ attachment failure rate
Adverse events i.e., bracket failure rate in Group A and attachment failure rate in Group B were recorded in both participants' notes and the data collection sheet. The patient's provider noted in the clinical chart every bracket that had bond failure during the course of the study trial period. The brackets on the molar teeth were omitted. Brackets that debonded twice or more on the same tooth were counted only once. At the end of 180 days post-bonding, the percentage of broken brackets was calculated as: number of debonded brackets divided by the total number of teeth bonded (excluding molar teeth).
Time frame: Through alignment, an average of 6 months
Chair side time
The average time taken at the initial banding and bonding visit for the group A and the initial attachment bonding and aligner delivery visit for group B along with multiple routine mid-treatment appointments for both the groups during the alignment phase of treatment, as well as one emergency appointment for both measured using a digital stopwatch. The appointment times were rounded to the nearest minute with the total chair side time beginning when the patient sits on the chair and ending when they stood up to leave.
Time frame: Through alignment, an average of 6 months
Treatment Efficiency Index
The treatment efficiency index calculated by measuring the average Little's irregularity index before treatment and dividing it by the average treatment time in months/ days for alignment of the mandibular incisors.
Time frame: Through alignment, an average of 6 months
BANA (Microbial-enzymatic N-benzoyl-DL-arginine-2-napthylamide) Score
Microbiological index for the subgingival plaque
Time frame: Baseline, after 3 months, and after 6 months
Immunological Assay using ELISA
Immunological assay cytokine IL-1Beta in the gingival crevicular fluid
Time frame: Baseline, after 3 months, and after 6 months
Patient's occlusal comfort level
Patient's occlusal comfort level assessed by means of a Visual Analog Scale with a score from 0 - 10, 0 being least comfortable and 10 being most comfortable
Time frame: Baseline, and after an average of 6 months, and after treatment an average of 1 year
Changes in mandibular incisor inclination
Changes in mandibular incisor inclination as measured on the lateral cephalogram
Time frame: Baseline, and after an average of 6 months
Changes in the mandibular arch form
Changes in the mandibular arch form as measured on the study model
Time frame: Baseline, and after an average of 6 months
Plan to share: Yes — All IPD collected throughout the trial
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report
Time frame: IPD will be available once the trial is finalized up to 3 years post recruitment
Access criteria: Principle investigator and researchers will have access to all IPD collected throughout the trial once it has been depersonalized.
Started Oct 2023 (actual). Primary completion is estimated for Dec 2028, 62 months after the start.
Of 50 non-industry interventional studies with no phase under Crowding, half reached primary completion within 17 months of starting (the median), counting those still running; a quarter within 11 and three quarters within 28. This study's planned 62 months is above that.
Counting every sponsor, half of 52 studies reached it within 17 months; a quarter within 11 and three quarters within 28.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
No contact was published for this record. The registry link below has the sponsor’s details.
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.
University of Sharjah