Occlusal Changes with Clear Aligners and the Case Complexity Influence: A Longitudinal Cohort Clinical Study

Area of Science:

• Orthodontics
• Dental Biomaterials
• Biotechnology

Background:

• Clear aligners (CA) are worn 22 hours daily, potentially affecting occlusion.
• This study investigates occlusal changes throughout CA treatment and their correlation with case complexity and facial biotype.

Purpose of the Study:

• Analyze occlusal changes at different stages of clear aligner treatment.
• Compare planned versus achieved occlusal contacts.
• Identify challenging tooth movements and their impact on treatment completion.
• Evaluate the relationship between occlusal changes, case complexity, and facial biotype.

Main Methods:

• Longitudinal cohort study design with a sample of 82 individuals.
• Malocclusion complexity classified using Invisalign® evaluation tools (simple, moderate, complex).
• Quantitative analysis of occlusal data using specialized software (Meshlab®, ClinCheck®, My-Itero®).

Main Results:

• Statistically significant decrease in occlusal area and contacts from T0 to T1.
• Occlusal area changes differed significantly between hyperdivergent and hypodivergent facial biotypes.
• Achieved anterior occlusal contacts were significantly higher than planned.
• Significant increases in occlusal areas and contacts observed between T1 and T2 (post-treatment).

Conclusions:

• Clear aligner treatment results in reduced occlusal contact area and number.
• Anterior contacts tend to be overcorrected, while posterior contacts increase post-treatment.
• Distalization, rotation, and posterior extrusion are the most challenging tooth movements in CA therapy.