Effectiveness of Clear Aligner Systems in Mixed Dentition Maxillary Transverse Deficiency

Comparison of the Effectiveness of Different Clear Aligner Systems in Patients With Maxillary Transverse Deficiency During the Mixed Dentition Period: An In-Vivo Randomized Controlled Clinical Trial

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.

Inclusion Criteria:

• 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.

Exclusion Criteria:

• 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