Predictability of Dental Distalization with Clear Aligners: A Systematic Review

Abstract

The current review aims to evaluate the scientific evidence relating to the effectiveness of treatment with clear aligners (CAs) in controlling distalization orthodontic tooth movement. "Orthodontics, aligners" and "distalization" were the search terms used on the Scopus, Web of Science and Pubmed databases with the Boolean operator "AND". The results of the last ten years of research were 146 studies; of these, 19 publications were included for this review. The distalization movement is possible with invisible masks alone, but the risk of losing anchorage in the anterior sectors is very probable. The stability of the results and the reduction of unwanted effects can be guaranteed by the use of skeletal anchoring devices and interproximal enamel reduction (IPR), with which compensations are obtained to reduce the initial overjet. Temporary anchorage devices (TADs) can be used to manage posterior anchorage after distalization of maxillary molars with aligners. This hybrid approach has demonstrated the greatest orthodontic success. TADs are useful aids to provide direct and indirect skeletal anchorage. The opposite effect must be considered when planning dental distalization, especially of the molars, in patients with large overjet, and corrective measures or the use of auxiliaries may be necessary to prevent midcourse corrections. This systematic review provides a critical evidence-based assessment of the predictability of dental distalization with CAs, an ever-evolving orthodontic technique.

Keywords: alignment; clear aligner therapy (CAT); malocclusion; molar distalization; orthodontics; tooth movement.

Figure 1

Dental distalization movement is illustrated. The arrow indicates the direction of tooth distalization.

Figure 2

ClinCheck simulation of orthodontic distalization is illustrated.

Figure 3

Prisma Flow chart.

Figure 4

Risk of bias is illustrated; red indicates high risk, and green indicates low risk of bias. Judgment: + low concerns; ? no informations; − very high concerns [1,15,24,25,26,27,28,29,30,31,32,33,34,35,36,38,39,40].

Figure 5

Examples of superimposition of pre- (a) and post-treatment (b) digital models of orthodontic clinical cases are presented, via digit.

Figure 6

Distalization of the canine in an orthodontic treatment with CAT, with extraction of the first upper premolar, is presented. The arrow indicates the direction of tooth distalization.