JOCR Journal

Abstract

Objective - To measure the ability of digital planning software to accurately predict the final position of the dentition when fabricated in-office.

Setting and Sample Population – Two private practices located in Indiana. Sixty-one patients (thirty-eight maxillary arches and twenty-three mandibular arches) were assessed.

Materials and Methods - This retrospective study evaluated pre-treatment, predicted, and post-treatment digital scans that were superimposed for assessment of tooth movements. The difference between the achieved and desired final tooth positions was evaluated by superimposing achieved and desired final models. Predicted values were obtained by superimposing the final STL file to the planned digital setup. Superimpositions were completed and measured with the best-fit analysis in Geomagic software (3D Systems, Rock Hill, South Carolina).

Results - 72% of the predicted mandibular movements and 83% of the predicted maxillary movements met the clinically acceptable threshold of ≥0.5 mm. Significant differences were found between points on teeth and between tooth regions of separate teeth for the mandible and maxilla. Only maxillary teeth showed significant differences between teeth.

Conclusion - In-office fabrication of clear aligners appears to lead to clinically acceptable results with the majority of planned movements being achieved within 0.5 mm. Canines were more predictable in the mandible. In the maxilla, it was significantly more difficult to achieve planned torque on lateral incisors, and rotations measured at interproximal points were less often achieved by incisors compared to the canines.

Keywords – Aligner efficacy, Clear aligners, Orthodontic tooth movement, treatment design