Accuracy of Invisalign® treatments in the anterior tooth region. First results

Abstract

Aim: To analyse (a) to what extent the pretreatment model at the beginning of the treatment corresponds to the initial position in the ClinCheck® and (b) to what extent the predicted treatment result corresponds to the actual result of the therapy at the end of the treatment.

Material and methods: Pre- and posttreatment models as well as the initial and final position of the ClinCheck with a total of 35 patients aged between 15 and 59 were measured; all of whom were treated by using the Invisalign® technology (Invisalign®, Align Technology, S.C., Calif., USA). The measurement of the initial and final models was conducted by using an electronic digital calliper rule, i.e. that of ClinCheck® using the measurement tool ToothMeasure® of Invisalign® Software. The following parameters in the anterior region were measured: Overjet, Overbite, dental midline shift.

Results: Pretreament models and the initial ClinChecks® revealed slight deviations in the parameters overjet 0.08 mm (standard deviation (SD) 0.3), overbite 0.3 mm (SD 0.4) and dental midline deviation 0.1mm (SD 0.4). The final model and the final ClinCheck® revealed larger deviations: the differences for the Overjet were on average 0.4 mm (SD 0.7), Overbite 0.9 mm (SD 0.9) and dental midline shift 0.4 mm (SD 0.5).

Conclusions: The IT-based transmission of mal-aligned teeth into the ClinCheck® presentation provides sufficiently good accuracy. Tooth corrections in the vertical plane were more difficult to realize. A vertical overcorrection in the final ClinCheck®, a case refinement at the end of the treatment or additional measures (e.g. horizontal beveled attachments or vertical elastics) seems useful to achieve the individually intended therapeutic goal.