Comparison of Alignment Efficiency, Arch Dimensional Changes, and Passive Extraction Space Closure Between Self-Ligating and Conventional Brackets (SLBs CBs RCT)

Comparison of Alignment Efficiency, Arch Dimensional Changes, and Passive Extraction Space Closure Between Self-Ligating and Conventional Brackets: A Prospective Randomized Clinical Trial

Purpose:

This study aims to compare two types of orthodontic braces - self-ligating brackets (SLBs) and conventional brackets (CBs) - to see which one aligns teeth faster, affects the width of the dental arch, and closes spaces after premolar extractions more efficiently.

Who Can Join:

Ages 13-30 years Moderate to severe dental crowding Skeletal Class I or mild to moderate Class II malocclusions Good oral hygiene Requiring extraction of premolars

What Participants Will Do:

Participants are randomly assigned to either the SLB group or the CB group. Braces are bonded to the teeth following standard orthodontic procedures. Dental impressions and measurements will be taken at baseline, 3, 6, and 9 months.

No extra devices (like power chains) will be used for space closure during the study.

What is Being Measured:

Alignment of teeth using Little's Irregularity Index Intercanine and intermolar widths (arch dimensions) Passive closure of extraction spaces

Why This Study is Being Done:

The study investigates whether SLBs provide any clinical advantage over conventional braces in terms of faster alignment, arch width changes, and efficient space closure in extraction cases. This could help orthodontists make evidence-based decisions when choosing braces.

Study Duration:

Total observation period: 9 months Monthly follow-ups for adjustments and measurements

Study Overview

• Status: Completed
• Conditions: Dental Crowding; Passive Extraction Space; Intercanine Width; Intermolar Width
• Intervention / Treatment: Device: Self-Ligating Brackets (SLB); Device: Conventional Bracket

Detailed Description

This prospective, randomized controlled trial was conducted to evaluate the clinical effects of self-ligating brackets (SLBs) versus conventional brackets (CBs) in patients requiring premolar extractions. The study included 70 participants aged 13-30 years with moderate to severe crowding and skeletal Class I or mild-to-moderate Class II malocclusions.

Participants were randomly assigned to either the SLB or CB group (35 participants each) using computer-generated random numbers and allocation concealment through sequentially numbered, opaque, sealed envelopes. Blinding of the operator and participants was not possible due to the nature of the interventions; however, outcome assessors were blinded by covering brackets on dental casts with beading wax.

The study assessed alignment efficiency, arch dimensional changes, and passive extraction space closure over a 9-month period. Dental impressions and study casts were collected at baseline, 3, 6, and 9 months. Alignment was quantified using Little's Irregularity Index, while intercanine and intermolar widths and passive extraction space closure were measured using digital calipers. No active space-closing auxiliaries, such as power chains or springs, were used during the observation period.

All treatments were performed by trained orthodontic residents with calibration to ensure consistency in bonding procedures, archwire sequence, and ligation methods. Linear mixed-effects models with repeated measures and covariates (age, gender, and malocclusion type) were used for statistical analysis, and regression coefficients with 95% confidence intervals were reported.

The trial aims to determine whether SLBs differ from conventional brackets in terms of alignment speed, arch dimensional changes, and passive space closure in extraction cases. Findings from this study can inform evidence-based bracket selection and clinical decision-making in orthodontic practice.

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Pakistan
  • Punjab Province
    • Lahore, Punjab Province, Pakistan, 2500
      • Marium Jamil

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria Age 13-30 years, any gender Moderate (4-8 mm) or severe (>8 mm) dental crowding Skeletal Class I (ANB 0-20) or mild-to-moderate Class II (ANB 3-50) Normal or vertical growth pattern (FMA 22-280) Good oral hygiene (plaque index ≤1) Require extraction-based orthodontic treatment

Exclusion Criteria Previous orthodontic treatment Asymmetric extractions Systemic diseases or medications affecting bone metabolism Cleft lip/palate or other craniofacial anomalies Congenital absence of teeth (except third molars) Low-angle (hypodivergent) growth pattern Inability to comply with treatment/follow-up

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Conventional Bracket Group (CB); Participants in this group received 0.022-inch slot conventional MBT brackets (Dentaurum, Germany) bonded to all teeth up to the second premolars. Alignment started with 0.014-inch NiTi archwires and progressed according to a standardized archwire sequence. Stainless steel lacebacks were used for early canine control, and no active space-closing auxiliaries (e.g., power chains or closed-coil springs) were applied during the 9-month observation period. Outcome measurements were taken at baseline, 3, 6, and 9 months on blinded study casts.	Device: Self-Ligating Brackets (SLB); Participants received 0.022-inch slot MBT conventional brackets (Equilibrium 2, Dentaurum, Germany) bonded to all teeth up to the second premolars. Alignment began with 0.014-inch NiTi archwires and progressed through the same standardized sequence as the SLB group. Stainless steel lacebacks were applied for early canine control. No active space-closing auxiliaries (power chains or closed-coil springs) were used during the 9-month observation period. Outcome measurements were taken at baseline, 3, 6, and 9 months on blinded study casts.
Experimental: Self-Ligating Bracket Group (SLB); Participants in this group received 0.022-inch slot self-ligating MBT brackets (American Orthodontics, USA) bonded to all teeth up to the second premolars. Alignment started with 0.014-inch NiTi archwires and progressed using the same standardized archwire sequence. Stainless steel lacebacks were applied for early canine control, and no active space-closing auxiliaries were used during the 9-month observation period. Outcome measurements were taken at baseline, 3, 6, and 9 months on blinded study casts.	Device: Conventional Bracket; Participants in this arm received 0.022-inch slot MBT conventional brackets (Equilibrium 2, Dentaurum, Germany) bonded to all teeth up to the second premolars. Alignment began with 0.014-inch NiTi archwires and progressed using a standardized archwire sequence (0.016, 0.018 NiTi, 0.016×0.022 NiTi, 0.019×0.025 stainless steel). Stainless steel lacebacks were applied for early canine control, and no active space-closing auxiliaries (e.g., power chains or NiTi closed-coil springs) were used during the 9-month observation period. Outcome measurements were taken at baseline, 3, 6, and 9 months on blinded study casts.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dental alignment assessed by Little's Irregularity Index	The primary outcome is the degree of dental alignment in extraction cases, measured on study casts using Little's Irregularity Index. Measurements were performed by a single calibrated examiner blinded to bracket type using a digital caliper (0.01 mm accuracy). Higher scores indicate greater crowding, while lower scores indicate improved alignment.	Baseline (T₀) to 9 months (T₃), assessed at 3-month intervals
Intermolar width	The primary outcome is the degree of dental alignment in extraction cases, measured on study casts using Little's Irregularity Index. Measurements were performed by a single calibrated examiner blinded to bracket type using a digital caliper (0.01 mm accuracy). Higher scores indicate greater crowding, while lower scores indicate improved alignment.	Baseline (T₀) to 9 months (T₃), assessed at 3-month intervals

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intercanine width	Distance between the cusp tips of the canines on study casts. Measured by a blinded examiner using a digital caliper (0.01 mm accuracy) to monitor transverse changes in the anterior arch.	Baseline (T₀) to 9 months (T₃), assessed at 3-month intervals
Passive extraction space closure	Measured at extraction sites as the distance between nearest reproducible points on crowns adjacent to extraction sites. No active space-closing auxiliaries were used to isolate the effect of bracket type. Measured by a blinded examiner using digital calipers.	Baseline (T₀) to 9 months (T₃), assessed at 3-month intervals

Collaborators and Investigators

• Sponsor: Saidu College of Dentistry

Publications and helpful links

General Publications

• 14. Scott P, DiBiase AT, Sherriff M, Cobourne MT. Alignment efficiency of Damon3 self-ligating and conventional orthodontic bracket systems: a randomized clinical trial. American journal of orthodontics and dentofacial orthopedics. 2008;134(4):470. e1-. e8. 2. Fleming PS, DiBiase AT, Sarri G, Lee RT. Comparison of mandibular arch changes during alignment and leveling with 2 preadjusted edgewise appliances. American Journal of Orthodontics and Dentofacial Orthopedics. 2009;136(3):340-7. 3. Pandis N, Polychronopoulou A, Katsaros C, Eliades T. Comparative assessment of conventional and self-ligating appliances on the effect of mandibular intermolar distance in adolescent nonextraction patients: a single-center randomized controlled trial. American journal of orthodontics and dentofacial orthopedics. 2011;140(3):e99-e105.

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2024
• Primary Completion (Actual): June 25, 2025
• Study Completion (Actual): June 25, 2025

Study Registration Dates

• First Submitted: March 25, 2026
• First Submitted That Met QC Criteria: March 25, 2026
• First Posted (Actual): March 31, 2026

Study Record Updates

• Last Update Posted (Actual): March 31, 2026
• Last Update Submitted That Met QC Criteria: March 25, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Dental crowding; Self-ligating brackets; Conventional brackets; Orthodontic alignment
• Additional Relevant MeSH Terms: Behavior; Spatial Behavior; Crowding
• Other Study ID Numbers: UHS-ORTHO-2026-01 (Other Identifier: The University of Lahore, Pakistan)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual participant data (IPD) will include de-identified demographic, clinical, and outcome measurements (Little's Irregularity Index, intercanine and intermolar widths, arch depth, passive extraction space) collected during the trial. No personal identifiers will be included. Supporting documents such as study protocol, statistical analysis plan, and analytic code will also be shared.
• IPD Sharing Time Frame: IPD and supporting information will be available from 6 months after publication of the trial results and remain accessible for 5 years.
• IPD Sharing Access Criteria: Qualified researchers can access the data for scientific purposes upon request. Requests require a brief proposal and agreement to data use terms to protect participant confidentiality. Data will be shared via secure email or repository upon request.
• IPD Sharing Supporting Information Type: SAP; ANALYTIC_CODE

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No