An interventional study of Self-ligating orthodontic brackets and Conventional orthodontic brackets in Malocclusion Class I and Crowding of Teeth, sponsored by Future University in Egypt. Completed at 1 site in Egypt. Open to participants aged 18 Years to 25 Years. Per ClinicalTrials.gov, last updated 2026-10-16.
Sponsored by Future University in Egypt · Not applicable, Interventional, and Treatment
This randomized clinical trial compares two types of orthodontic brackets, self-ligating and conventional, in adults aged 18 to 25 with moderate crowding of the lower front teeth (4 to 8 mm). The main question is whether the type of bracket affects the thickness of the thin bone covering the front surface of the lower incisor roots (labial alveolar bone) during the leveling and alignment phase of treatment. Some clinicians claim that self-ligating brackets with light-force copper-nickel-titanium wires let the bone adapt and follow the teeth, while others report bone thinning with both systems. Twenty participants will be randomly assigned to self-ligating or conventional brackets. Bone thickness will be measured on cone beam computed tomography (CBCT) scans taken before treatment and at the end of leveling and alignment. The study will also compare the speed of alignment, changes in tooth inclination (torque and tip), pain, root resorption, and periodontal health between the two groups.
Dental crowding is one of the most common malocclusions. Non-extraction treatment is increasingly popular, but moving teeth beyond the alveolar housing can lead to bone dehiscence, fenestration, and gingival recession, especially in the lower incisor region. Self-ligating bracket systems are claimed to produce a "Frankel-like effect", in which low-friction brackets and light-force Cu-NiTi wires allow the arch to reshape physiologically with the alveolar bone following the teeth. Clinical evidence for this claim is limited and conflicting.
Design: Two-arm, parallel-group randomized clinical trial with a 1:1 allocation ratio, reported according to CONSORT guidelines, conducted at the Orthodontic Department clinic, Faculty of Oral and Dental Medicine, Future University in Egypt.
Null hypothesis: There is no difference in the change in lower labial alveolar bone thickness between self-ligating and conventional brackets.
Randomization: A computer-generated random sequence (Microsoft Excel RAND function) will be produced by the study supervisor. Allocation will be concealed in sealed, opaque, folded envelopes kept in a box at the secretary's office. Patients will draw an envelope before bonding.
Blinding: Operator and participants cannot be blinded. Outcome assessors will be blinded; patient identifiers will be removed from radiographs and models, and two assessors will measure independently.
Interventions:
Conventional group: 0.022-inch slot Roth prescription stainless steel brackets (American Orthodontics) with elastomeric ligatures. Wire sequence: 0.012 and/or 0.014-inch NiTi (chosen according to crowding), 0.016-inch NiTi, 0.016 x 0.022-inch NiTi, then 0.017 x 0.025-inch stainless steel for 4 weeks.
Self-ligating group: Roth prescription self-ligating brackets (American Orthodontics). Wire sequence: 0.014-inch Cu-NiTi for at least 10 weeks, 0.014 x 0.025-inch Cu-NiTi for at least 10 weeks, then 0.017 x 0.025-inch stainless steel customized to arch form for 4 weeks.
Patients will be reviewed monthly, with an intraoral scan at each visit. CBCT, standardized photographs, intraoral scans, and periodontal evaluation will be taken at baseline (T0) and at the end of leveling and alignment (T1).
Sample size: Using G*Power 3.1.9.7 with alpha 0.05, power 80%, and effect size d = 1.51 from a previous study, 16 participants are needed (8 per group), increased by 20% for dropout to 20 (10 per group).
Statistical analysis: Normality will be checked with Kolmogorov-Smirnov and Shapiro-Wilk tests. Normally distributed data will be compared with independent t-tests, and non-normal data with the Mann-Whitney U test. Categorical data will be analyzed with chi-square tests. Significance is set at p ≤ 0.05 (IBM SPSS Statistics v26). Intra- and inter-examiner reliability will be assessed with the intraclass correlation coefficient and kappa.
24 studies on the registry are indexed under Crowding; 10 are open to participants now.
This study's enrollment of 20 is below the median of 34 across 19 interventional studies indexed under Crowding.
Browse Crowding studies →Future University in Egypt is the lead sponsor of 103 studies on the registry; 30 are open to participants now.
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Exclusion Criteria:
Lower arch leveling and alignment using Roth prescription self-ligating brackets with 0.014" Cu-NiTi, 0.014"x0.025" Cu-NiTi, then 0.017"x0.025" stainless steel archwires. over a duration of 6 months
Device: Self-ligating orthodontic brackets
Lower arch leveling and alignment using 0.022" slot Roth prescription conventional brackets with elastomeric ligatures and 0.012"/0.014" NiTi, 0.016" NiTi, 0.016"x0.022" NiTi, then 0.017"x0.025" stainless steel archwires. over a duration of 6 months
Device: Conventional orthodontic brackets
Self-ligating brackets (American Orthodontics, Roth prescription) bonded to the lower teeth with a light-force Cu-NiTi archwire sequence until leveling and alignment are complete. over a duration of 6 months
Conventional stainless steel brackets (American Orthodontics, Roth prescription, 0.022 x 0.028" slot) ligated with elastomeric O-ties with a NiTi archwire sequence until leveling and alignment are complete. over a duration of 6 months
Change in labial alveolar bone thickness of lower anterior teeth
Labial bone thickness measured in millimeters on CBCT scans using 3Shape software, compared between baseline and end of leveling and alignment.
Time frame: Baseline (T0) and end of leveling and alignment (T1), approximately 6 months
Rate of lower incisor alignment
Little's Irregularity Index (mm) measured on monthly digital intraoral scans using 3Shape software, expressed as mm per month.
Time frame: Monthly from baseline to end of leveling and alignment, approximately 6 months
Change in torque of lower anterior teeth
Labiolingual inclination measured on CBCT in degrees (angular) and millimeters (linear) using 3Shape software.
Time frame: T0 and T1, approximately 6 months
Change in tip of lower anterior teeth
Mesiodistal angulation measured on CBCT in degrees (angular) and millimeters (linear) using 3Shape software.
Time frame: T0 and T1, approximately 6 months
Pain intensity
Visual analogue scale (0 to 10) recorded by participants.
Time frame: At first archwire insertion, after 24 hours, after 7 days, then monthly until end of leveling and alignment which is approximately 6 months
Root resorption of lower anterior teeth
Graded on CBCT using the Levander and Malmgren 5-grade scoring system.
Time frame: T0 and T1, approximately 6 months
Periodontal status
Probing depth (mm) and clinical attachment loss (mm) measured by the same periodontist.
Time frame: T0 and T1, approximately 6 months
Plan to share: No — Data will be accessible only to the supervisors and principal investigator to protect participant confidentiality.
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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