Influence of Attachments and Interproximal Reduction on the Accuracy of Canine Rotation with Invisalign

Abstract

Objective: To evaluate the influence of attachments and interproximal reduction on canines undergoing rotational movement with Invisalign. Materials and Methods: In this prospective clinical study, 53 canines (33 maxillary and 20 mandibular) were measured from the virtual TREAT models of 31 participants treated with anterior Invisalign. The pretreatment virtual model of the predicted final tooth position was superimposed on the posttreatment virtual model using ToothMeasure, Invisalign's proprietary measurement software. A one-way analysis of variance (ANOVA) (P Ͻ .05) compared three treatment modalities: attachments only (AO), interproximal reduction only (IO), and neither attachments nor interproximal reduction (N). Student's t-tests (P Ͻ .05) compared the mean accuracy of canine rotation between arches. Results: The mean accuracy of canine rotation with Invisalign was 35.8% (SD ϭ 26.3). Statistical analyses indicated that there was no significant difference in accuracy between groups AO, IO, and N (P ϭ .343). There was no statistically significant difference (P ϭ .888) in rotational accuracy for maxillary and mandibular canines for any of the treatment groups. The most commonly prescribed attachment shape was the vertical-ellipsoid (70.5%). Conclusions: Vertical-ellipsoid attachments and interproximal reduction do not significantly improve the accuracy of canine rotation with the Invisalign system.

Efficacy of clear aligners in controlling orthodontic tooth movement: A systematic review

“…Eleven relevant publications were identified: four studies 5,10-12 were retrospective non-randomized, five studies 4,[13][14][15][16] were prospective non-randomized, and two studies 17,18 were prospective randomized. The article selection process is illustrated in the PRISMA Flow Diagram (Figure 1).…”

“…Thus, teeth with rounded crowns seem to be more difficult to rotate with CAT. Furthermore, in 2008 Kravitz et al 13 stated that IPR influenced in a positive way the correction of rotations, while in 2005 Djeu et al 10 supported the use of attachments to improve the accuracy of this movement. In their retrospective study, Simon et al, 12 analyzing premolar rotations of .10u, concluded that the use of attachments and the amount of movement per aligner had a great impact on the treatment predictability; reducing the staging and using attachments increase the predictability of tooth movement.…”

“…4,5,[11][12][13] Thus, conclusions with a limited level of evidence could be drawn from the review process. The most recurrent sources of bias were related to the study design, the sample size, and the lack of control group.…”

“…A prospective study 13 conducted on 53 canines of 31 subjects assessed a mean accuracy for canine rotation of 36%. Canines that received interproximal reduction (IPR) reported the highest mean rotational accuracy and lowest standard deviation (43%; SD 5 22.6%).…”

Use of Magnetic Forces in Orthodontics: A Review

“…Attachments are generally placed on the teeth to increase the undercuts and retention of the appliance to facilitate the desired tooth movement [18]. However, the current attachments are considered to be only partially effective [32], [33]. An improved system utilizing small magnetic attachments has been put forward to enhance the capabilities of this appliance.…”