Predicted and actual outcome of anterior intrusion with Invisalign assessed with cone-beam computed tomography

Abstract

The purpose of this study was to compare predicted anterior teeth intrusion measurements with the actual clinical intrusion measurements using cone-beam computed tomography. Understanding the precision of the software in anticipating changes may help practitioners predict the need for overcorrection. Twenty-two patients, with a mean age of 23.74years, who underwent Invisalign (AlignTechnology, Santa Clara, Calif) clear aligners treatment for both arches only after having completed treatment with an initial series of aligners were included in this study. The pretreatment and posttreatment cone-beam computed tomography scans after the initial series were acquired by a single orthodontist practitioner. ClinCheck measurements were recorded with Align Technology. The long axis of the anterior tooth intrusion movement was measured in 142 teeth. A comparison between the predicted and actual measurements of anterior intrusion of the teeth was performed, and the intraclass correlation coefficients showed an almost perfect agreement in the linear measurements. A statistically notable difference between the predicted and actual measurements of anterior intrusion. The predicted intrusion movement of the maxillary canines (P=0.001), maxillary lateral incisors (P<0.0001), and maxillary central incisors (P<0.0001) significantly differed from the actual values. Similarly, the intrusion movement in the mandibular teeth seemed to be inaccurate, with significant differences in the mandibular canines (P<0.0001) and mandibular lateral and central incisors (P<0.0001). The mean precision of true anterior intrusion with Invisalign clear aligners was 51.19%, and the mean amount of correction was 48.81%. The use of other supplementary methods of anterior teeth intrusion may be helpful to reduce the rate of midcourse corrections and refinements.