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

Future University in Egypt20 enrolled

Overview

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 Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

Conditions

Dental Crowding Alveolar Bone Loss Malocclusion

Interventions

Fixed orthodontic applianceDEVICE

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.

Clear alignersDEVICE

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.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 25 YearsHealthy volunteers:

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

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.

Time frame: Baseline (T0) and end of alignment phase (T3)) (approximately 6 months)

Secondary Outcomes

Change in alveolar bone thickness

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.

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

Change in mandibular incisor inclination (torque)

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.

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

Rate of alignment (Little's Irregularity Index)

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.

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