Enamel interproximal reduction during treatment with clear aligners: digital planning versus OrthoCAD analysis.
Level 4 - case-series / case-control
Single-center observational study evaluating pre- and post-treatment digital models without an independent control group
PubMed 33874922 · doi:10.1186/s12903-021-01487-2
What was done
Thirty patients (14 males, 16 females; mean age 24.53 ± 13.41 years) with mild to moderate dento-alveolar discrepancy (1.5–6.5 mm) treated with Invisalign clear aligners were evaluated to compare digitally planned interproximal enamel reduction (IPR) on ClinCheck with actual performed IPR. Pre-treatment (T0) and post-treatment before refinement (T1) digital models derived from iTero scans were analyzed using OrthoCAD software. Mesiodistal widths of all teeth excluding molars were measured at T0 and T1, and total enamel reduction was compared to ClinCheck planning using dependent sample t-tests.
What was found
In the upper arch, planned IPR averaged 0.62 mm and actual performed IPR averaged 0.62 mm (mean difference 0.00 mm). In the lower arch, planned IPR averaged 1.92 mm and actual performed IPR averaged 1.93 mm (mean difference 0.01 mm).
Why it matters
This study demonstrates that clinical execution of interproximal enamel reduction in clear aligner treatment can closely match digital planning.
Limits
The sample size was small (n = 30) from a single institution. Enamel removal was reported as aggregate sums per arch rather than site-specific or individual contact-point measurements, and measurements were derived from digital optical models rather than direct physical enamel thickness assessments.