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

NCT07716007 | Completed

• 1 other identifier: FUE.REC (18)/7-2024
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Dental Crowding; Alveolar Bone Loss; Malocclusion

Keywords

clear aligners; fixed orthodontic appliances; alveolar bone level; alveolar bone thickness; cone-beam computed tomography; incisor inclination; torque; Little's Irregularity Index; rate of alignment; non-extraction treatment; adults

Outcome Measures

Primary Outcomes (1)

• Change in alveolar bone level

  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 Outcomes (3)

• Change in alveolar bone thickness

  Baseline (T0) and end of alignment phase (≈ 6 months)

• Change in mandibular incisor inclination (torque)

  Baseline (T0) and end of alignment phase (≈ 6 months)

• Rate of alignment (Little's Irregularity Index)

  Baseline (T0), 8 weeks (T1), 16 weeks (T2) and end of alignment (T3, ≈ 24 weeks / 6 months)

Study Arms (2)

Fixed appliances (Group FA)

ACTIVE COMPARATOR

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

Clear aligners (Group CA)

EXPERIMENTAL

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

Interventions

Fixed orthodontic appliance DEVICE

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.

Also known as: Conventional labial brackets, pre-adjusted edgewise appliance (0.022 MBT)

Fixed appliances (Group FA)

Clear aligners DEVICE

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.

Also known as: sequential clear aligners, Thermoformed removable aligners

Clear aligners (Group CA)

Eligibility Criteria

• Age: 18 Years - 25 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Future University in Egypt: lead

Study Sites (1)

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

Cairo, 11865, Egypt

Location

MeSH Terms

Conditions

Crowding; Alveolar Bone Loss; Malocclusion

Interventions

Orthodontic Appliances, Fixed

Condition Hierarchy (Ancestors)

Spatial Behavior; Behavior; Bone Resorption; Bone Diseases; Musculoskeletal Diseases; Periodontal Atrophy; Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Tooth Diseases

Intervention Hierarchy (Ancestors)

Orthodontic Appliances; Orthodontics; Dentistry

Study Officials

• ahmed mohamed hesham elzoghary

  Faculty of Oral and Dental Medicine, Future University in Egypt

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: Participants and care providers cannot be masked because the two appliances are visibly different. All CBCT and digital-model measurements are performed by independent outcome assessors blinded to group allocation, and the statistician analyses coded data.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Postgraduate researcher (orthodontic resident), Department of Orthodontics

Model Details: Two arms in parallel; participants are assigned 1:1 to clear aligners or fixed appliances for the full \~6-month levelling and alignment phase.

Study Record Dates

• First Submitted: July 15, 2026
• First Posted: July 21, 2026
• Study Start: August 15, 2024
• Primary Completion: July 25, 2025
• Study Completion: April 15, 2026
• Last Updated: July 21, 2026

Record last verified: 2026-07

Locations

EG (1)