Accuracy of Invisalign^® on Upper Incisors: A Systematic Review

Abstract

The current systematic review appraises the effectiveness of the types of tooth movements performed with Invisalign ® clear aligner on the maxillary incisors. An electronic literature search of published trials was performed through PubMed, LILACS, Scopus, Cochrane Library, and Web of Science databases, and selected journals, from 2009 to 2020. Out of 291 references, five relevant publications were identified for analysis: four studies were performed retrospectively and one prospectively, all non-randomized. Despite the limited set of selected articles, the sample size is significant, with 148 subjects included in the reviewed studies involving the orthodontic treatment of upper incisors. We concluded that movements with the Invisalign ® clear aligner on the upper incisors present distinct accuracy, possibly related with movement complexity; intrusion of the incisors has low accuracy (in some cases, 0% of accuracy was reported when the tooth extruded), while incisor extrusion exhibit some of the highest accuracy values reported in the included studies (45%-142%, when the achieved movement was greater than the predicted). Besides, axial (i.e., torque and tip) and horizontal (i.e., translation and rotation) movements are usually effective, with accuracy values between 39%-156% and 42%-79%, respectively. Overall, we determined that the efficiency of aligner to reach the desired movements in the upper incisors was low, as often refinements were required in the included studies. The use of aligner features must be more often considered to improve movement accuracy.

The predictability of arch expansion with the Invisalign First system in children with mixed dentition: a retrospective study

“…Studies have reported that the accuracy of arch expansion increases with the initial negative torque of the posterior teeth [14]. However, these findings differ from those reported by Gonçalves et al [17], who found that the predictability of mandibular arch expansion is less than that of the maxillary arch in patients with mixed dentition. This difference in tendency may be attributed to differences in the age distribution of the samples included in the studies, variation in the amount of arch expansion, the number of aligners used, and the attachment design during treatment planning.…”

“…Several studies have reported on the predictability of arch expansion using the Invisalign® system. However, most of the studies were conducted on adolescents or adults with permanent dentition [12][13][14][15], and there are few reports on the early mixed dentition stage where the Invisalign First® system can be used [16,17]. In addition, there are few studies on the clinical factors that can affect arch expansion [14].…”

A comparison of the upper anterior teeth movements with optimized and conventional attachment

“…( 14 ) found that the extrusion accuracy of superior incisors was 18.3%. Indeed, superior lateral incisors have a reduced size that is difficult for tooth movement, especially for extrusion movement ( 15 ).…”

Coronal Repercussions of the Maxillary Central Incisor Torque in the First Set of Aligners: A Retrospective Study

“…The aesthetic and comfort advantages, as well as the ease of cleaning, are points in favor of aesthetic aligners when compared to conventional fixed orthodontic appliances [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ]. Disadvantages related to the use of clear aligners include limited control root movement, limited intermaxillary correction, little or no control by the operator and full-time dependence by the patient, with the appliance being removed only for eating and sanitation [ 13 ].…”