Bone Level Changes Using Clear Aligners Compared to Fixed Appliances in Non-Extraction Treatment of Adults

July 15, 2026 updated by: Ahmed Mohamed Hesham, Future University in Egypt

Evaluation of Bone Level Changes Using Clear Aligners Compared to Fixed Appliances in Non-extraction Treatment of Adult Patients: A Randomized Clinical Trial

This study compares two common ways of straightening teeth in adults who have mild-to-moderate crowding of the lower front teeth and do not need any teeth removed: clear aligners and traditional fixed braces.

The main aim is to find out whether the two methods differ in how they affect the bone that surrounds the teeth. Using three-dimensional X-ray scans (cone-beam CT) and digital models of the teeth taken before and during treatment, the researchers measure the level and thickness of the bone around the lower front teeth, the tilt (inclination) of the lower front teeth, and how quickly the crowding is corrected.

Adults are randomly assigned to receive either clear aligners or fixed braces, and the same measurements are compared between the two groups over about six months.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Egypt
      • Cairo, Egypt, 11865
        • Faculty of Oral and Dental Medicine, Future University in Egypt (Department of Orthodontics)

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Adults 18-25 years of age, of both sexes.
  • Mild-to-moderate mandibular anterior crowding (2-6 mm).
  • Angle Class I molar relationship with normal overjet (1-3 mm) and overbite (1-2 mm).
  • Full permanent dentition with a healthy periodontium.
  • Normal anteroposterior and vertical skeletal pattern.

Exclusion Criteria:

  • Any local or systemic condition, or trauma, capable of affecting craniofacial growth and development.
  • History of previous orthodontic or interceptive treatment.
  • Loss of periodontal attachment.
  • Craniofacial anomalies, facial asymmetry or skeletal discrepancy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Fixed appliances (Group FA)
Conventional pre-adjusted edgewise fixed appliance (0.022-inch slot, MBT prescription) bonded from first molar to first molar; levelling and alignment with a sequence of nickel-titanium and stainless-steel archwires over approximately six months.
Device: Fixed orthodontic appliance
Brackets bonded first-molar-to-first-molar; alignment sequence 0.014" NiTi → 0.016" NiTi → 0.016 × 0.022" NiTi → 0.017 × 0.025" stainless steel. Interproximal reduction performed on assigned contacts where indicated.
Other Names:
  • Conventional labial brackets
  • pre-adjusted edgewise appliance (0.022 MBT)
Experimental: Clear aligners (Group CA)
Three-dimensionally printed, thermoformed clear aligners with bonded attachments and interproximal reduction as indicated; worn ~22 hours/day and changed per the digital staging, with clinical review every four weeks over approximately six months
Device: Clear aligners
Digital intraoral scan and staging (3Shape Ortho Analyzer); 3D-printed models thermoformed into aligners; attachments bonded where planned; sequential aligners worn ~22 h/day. Interproximal reduction per contact from canine-to-canine is done.
Other Names:
  • sequential clear aligners
  • Thermoformed removable aligners

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in alveolar bone level
Time Frame: Baseline (T0) and end of alignment phase (T3)) (approximately 6 months)
Change (mm) in the distance from the cemento-enamel junction to the alveolar crest on the labial and lingual aspects of the mandibular central incisors, lateral incisors and canines, measured on CBCT (OnDemand software), calculated as the difference between baseline and end-of-alignment values.
Baseline (T0) and end of alignment phase (T3)) (approximately 6 months)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in alveolar bone thickness
Time Frame: Baseline (T0) and end of alignment phase (≈ 6 months)
Change (mm) in labial and lingual alveolar bone thickness measured at 3 mm and 6 mm from the CEJ and at the root apex of the mandibular central incisors, lateral incisors and canines on CBCT (OnDemand software), from baseline to end of alignment.
Baseline (T0) and end of alignment phase (≈ 6 months)
Change in mandibular incisor inclination (torque)
Time Frame: Baseline (T0) and end of alignment phase (≈ 6 months)
Change (degrees) in the inner angle between the long axis of each mandibular central incisors, lateral incisors and canines and the mandibular plane, measured on the sagittal view of CBCT (Invivo/Anatomage software), from baseline to end of alignment.
Baseline (T0) and end of alignment phase (≈ 6 months)
Rate of alignment (Little's Irregularity Index)
Time Frame: Baseline (T0), 8 weeks (T1), 16 weeks (T2) and end of alignment (T3, ≈ 24 weeks / 6 months)
Reduction in mandibular anterior crowding quantified by Little's Irregularity Index (mm) - the sum of the displaced anatomic contact points from canine to canine - measured on serial digital models; the change across time points and the percentage improvement from baseline describe the rate of alignment.
Baseline (T0), 8 weeks (T1), 16 weeks (T2) and end of alignment (T3, ≈ 24 weeks / 6 months)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Future University in Egypt

Investigators

  • Principal Investigator: ahmed mohamed hesham elzoghary, Faculty of Oral and Dental Medicine, Future University in Egypt

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 15, 2024

Primary Completion (Actual)

July 25, 2025

Study Completion (Actual)

April 15, 2026

Study Registration Dates

First Submitted

July 15, 2026

First Submitted That Met QC Criteria

July 15, 2026

First Posted (Actual)

July 21, 2026

Study Record Updates

Last Update Posted (Actual)

July 21, 2026

Last Update Submitted That Met QC Criteria

July 15, 2026

Last Verified

July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • FUE.REC (18)/7-2024

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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