Comparison of the Predictability of Dentoalveolar Expansion With Two Clear Aligner Systems

Comparison of the Predictability of Dentoalveolar Expansion With Two Clear Aligner Systems: Angel Aligner Pro-Angel Aligner and Invisalign. A Longitudinal Clinical Study in Adult Patients.

To analyze the clinical predictability of transverse arch expansion achieved with two clear aligner systems (Invisalign, Angel Aligner-Angel Aligner Pro) by comparing planned and achieved dental movements through digital model analysis at different treatment stages using a repeatable and reproducible digital measurement technique.

The study population comprised 60 adult subjects (mean age: 33.93 ± 8.38 years) presenting with transverse maxillary and mandibular deficiencies requiring dentoalveolar expansion with clear aligners in both arches. Participants were divided into three homogeneous groups of 20 patients treated with different aligner systems: Angel Aligner-Angel Aligner Pro (Angelalign Technology Inc., Shanghai, China), and Invisalign (Align Technology Inc., San Jose, CA, USA). Digital models of the maxillary and mandibular arches were obtained at baseline (T1) using an iTero Element 5D intraoral scanner. Virtual treatment planning was performed using iOrtho (version 5.2) and ClinCheck (version 6.0 Pro) software, generating a virtual setup model (T2) that served as the reference for calculating prescribed orthodontic movements. After aligner fabrication, composite attachments were bonded using standardized protocols and manufacturer-provided templates to ensure reproducibility and accurate expression of planned tooth movements. Digital STL models obtained before treatment, after virtual setup, and at the end of treatment were analyzed using a repeatable and reproducible digital measurement technique to evaluate the predictability of transverse dentoalveolar expansion achieved with each aligner system.

Inclusion Criteria:

• Adult patients with a full permanent dentition
• Absence of auxiliary orthodontic appliances
• A clinical indication for transverse expansion in both dental arches
• Complete diagnostic and treatment records
• Treatment plans involving a minimum of 15 aligners before any refinement phase
• Confirmed adequate compliance with aligner wear (20-22 hours per day)
• patients with skeletal Class I or mild skeletal Class II or III relationships (ANB angle ranging from 0° to 4°

Exclusion Criteria:

• Severe dental crowding (tooth size-arch length discrepancy exceeding -5 mm)
• Active periodontal pathology
• Treatment plans involving dental extractions