Effectiveness of Clear Aligner Systems in Mixed Dentition Maxillary Transverse Deficiency

NCT07586163 | Active Not Recruiting

• 1 other identifier: 2025/189
• Study Type: interventional
• Target: 75
• Locations: 1 country
• Sites: 1

Brief Summary

he primary aim of this study is to compare the dentoalveolar and skeletal effects of arch expansion using an in-house clear aligner system, produced chairside with an indirect manufacturing technique, and commercially available clear aligner systems (Invisalign) in patients during the mixed dentition period. Participants will be allocated into five groups: Group A-In-house aligners (5-day activation protocol), Group B-In-house aligners (2-day activation protocol), Group C-Invisalign First aligners, Group D-Invisalign Palatal Expander, and Group E-untreated control group. Before treatment, demographic data, dental models, intraoral and extraoral photographs, radiographic images, and clinical measurements will be collected. Skeletal measurements, including maxillary and nasal widths, will be evaluated using posteroanterior cephalometric radiographs. Digital models of the maxilla and mandible will be obtained using an intraoral scanner and used for dental measurements before and after treatment. Secondary outcomes include evaluation of facial soft tissue changes using stereophotogrammetry (3DMD), assessment of white spot lesions using quantitative light-induced fluorescence (QLF), and analysis of patient compliance using the Orthodontic Patient Cooperation Scale. In addition, changes in body mass index (BMI), maxillary-mandibular transverse discrepancies, and appliance wear time will be evaluated.

Conditions

Maxillary Transverse Deficiency

Keywords

Clear aligners; Mixed dentition; Maxillary expansion

Outcome Measures

Primary Outcomes (1)

• Maxillary Transverse Dentoalveolar Dimension

  20 weeks

Secondary Outcomes (1)

• White spot lesion incidence

  20 weeks

Study Arms (5)

Invisalign Palatal Expander

EXPERIMENTAL

Device: Invisalign Palatal Expander Therapy

In-House Aligner (2-Day Protocol)

EXPERIMENTAL

Device: In-House Clear Aligner Therapy (2-Day Protocol)

In-House Aligner (5-Day Protocol)

EXPERIMENTAL

Device: In-House Clear Aligner Therapy (5-Day Protocol)

Invisalign First Aligner

ACTIVE COMPARATOR

Device: Invisalign First Aligner Therapy

Control Group

NO INTERVENTION

Interventions

Invisalign Palatal Expander Therapy DEVICE

In patients treated with the Invisalign Palatal Expander (IPE) (Align Technology, Santa Clara, CA), three-dimensional digital models were obtained using an intraoral scanner (iTero Lumina™, Align Technology). Individualized maxillary expansion amounts were prescribed based on clinical objectives. Unlike conventional aligner therapy, the IPE system does not involve full digital treatment simulation; expansion was defined by the planned transverse increase. Following approval, customized IPE appliance sets were manufactured and delivered. Patients were instructed to wear the appliance full-time, including during meals, removing it only for oral hygiene procedures. The activation protocol consisted of appliance changes every 2 days, providing 0.25 mm transverse expansion per stage. After completion of expansion, retention was achieved using Invisalign Palatal Holder appliances fabricated from new digital scans.

Invisalign Palatal Expander

In-House Clear Aligner Therapy (2-Day Protocol) DEVICE

In-house clear aligners were fabricated using a fully digital workflow. Digital impressions were obtained with an intraoral scanner (3Shape TRIOS), and maxillary models were processed in CAD software for segmentation and attachment planning. Buccal retention attachments were placed on primary canines, primary molars, and permanent first molars. Maxillary models were digitally expanded in 0.2 mm increments per stage, generating sequential STL files. Models were 3D-printed and thermoformed to fabricate aligners, which were then trimmed, polished, and labeled. Patients received five aligners at each visit and were instructed to change them every 2 days. Follow-up visits were scheduled at 10-day intervals. At each visit, treatment progress was assessed, and the next series of aligners was provided.

In-House Aligner (2-Day Protocol)

In-House Clear Aligner Therapy (5-Day Protocol) DEVICE

In-house clear aligners were fabricated using a fully digital workflow. Digital impressions were obtained with an intraoral scanner (3Shape TRIOS), and maxillary models were processed in CAD software for segmentation and attachment planning. Buccal retention attachments were placed on primary canines, primary molars, and permanent first molars to enhance retention and support transverse expansion. Models were digitally expanded in 0.2 mm increments per stage and converted into sequential STL files. These models were 3D-printed (Asiga MAX UV) and thermoformed (MINISTAR S) to produce aligners. The appliances were trimmed, polished, and labeled with sequence numbers. Patients received five aligners per visit and were instructed to change them every 5 days. Follow-up visits were scheduled at 25-day intervals, during which treatment progress was evaluated and new aligners were delivered.

In-House Aligner (5-Day Protocol)

Invisalign First Aligner Therapy DEVICE

In patients treated with Invisalign First (Align Technology, Santa Clara, CA), three-dimensional digital models were obtained using an intraoral scanner (3Shape TRIOS). Intraoral, extraoral photographs and radiographs were collected and uploaded to the ClinCheck digital treatment planning platform. Individualized treatment objectives were defined, and expansion was planned without concurrent tooth movement to isolate maxillary transverse effects. After achieving the desired expansion, comprehensive orthodontic treatment was continued. Virtual treatment plans were reviewed and revised when necessary before approval. Attachments were placed on posterior teeth to enhance retention and support expansion. Enamel surfaces were etched, bonded, and light-cured using standard orthodontic protocols. Patients were instructed to wear aligners 20-22 hours daily,and aligners were replaced every 5 days.

Invisalign First Aligner

Eligibility Criteria

• Age: 7 Years - 10 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17)

You may qualify if:

• Patients in the early mixed dentition period;
• Maxillary intermolar width ≤ 31 mm;
• Presence of at least 5 mm transverse discrepancy between the maxillary and mandibular arches;
• Normal vertical growth pattern (Sn-GoGn: 32 ± 6°);
• Eruption of permanent first molars and central incisors;
• Presence of at least two primary posterior teeth in each quadrant;
• Posterior teeth with a clinical crown height of at least 4 mm;
• Patients aged between 7 and 10 years;
• Absence of any craniofacial anomalies;
• Good oral hygiene status; Healthy periodontal tissues.

You may not qualify if:

• Patients with the loss of more than one primary tooth
• Presence of stainless steel crowns on the maxillary permanent first molars, primary first molars, or primary second molars
• Patients with systemic or syndromic conditions
• Presence of palatal exostoses or morphological anomalies of the palatal surface
• Presence of active temporomandibular joint disorders
• Children with poor compliance
• History of allergy to any dental material
• Patients with multiple and/or advanced caries, tooth agenesis, or supernumerary teeth
• Patients with skeletal asymmetry

Sponsors & Collaborators

• TC Erciyes University: lead

Study Sites (1)

Erciyes University Faculty of Dentistry

Talas, Kayseri, 38039, Turkey (Türkiye)

Location

MeSH Terms

Interventions

Clinical Protocols

Intervention Hierarchy (Ancestors)

Therapeutics; Epidemiologic Study Characteristics; Health Care Evaluation Mechanisms; Quality of Health Care; Health Care Quality, Access, and Evaluation

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor of Orthodontics

Study Record Dates

• First Submitted: May 3, 2026
• First Posted: May 14, 2026
• Study Start: May 26, 2025
• Primary Completion: May 1, 2026
• Study Completion: July 1, 2026
• Last Updated: May 14, 2026

Record last verified: 2026-05

Locations

TU (1)