European Journal of Molecular & Clinical Medicine

Aims and Objectives: The objective of this review is to search the literature on repositioners and present as to how it has emerged as a crucial treatment plan in modern orthodontics. The conventional orthodontic treatments were deemed tiresome since a lot of impressions had to be taken which demanded more clinical hours and efforts in the laboratories to manufacture appliances. Apart from this, aesthetics, and patient discomfort such as pain, longer duration of treatment, continuous wire adjustments, restrictive dietary habits, poor oral hygiene, patient compliance, were other areas of concern since a long time now. Clear aligners, which is a concatenation of removable thermoplastic polyurethane aligners, came into limelight as an aesthetic, comfortable, alternative to the traditional orthodontic treatments. This system makes use of CAD/CAM technology which plays a pivotal role in the success of clear aligners. This literature review aims to discuss about the advancements in the clear aligner system over the years and how it has proved to be an indispensable asset in Dentistry. However, certain limitations still need to be addressed to improve the efficiency of this system.

Aim: To assess the predictability of crowding resolution and the efficacy of different strategies to gain space during clear aligners treatment.
Methodology: 3D casts of a total of 40 subjects were evaluated. Thus, 80 arches were collected and uploaded on the Orthoanalyzer software for arch measurements. The data were gained on the starting arch form (T0), on the virtual arch developed with digital planning (vT1), and on the arch form achieved at the end of the aligner sequences (T1). The following parameters were scored: Little’s Irregularity Index, transversal arch diameters, (intercuspid, interpremolar, and intermolar width), incisor position/arch length, and enamel interproximal reduction (IPR).
Results: For all the measurements, statistically significant differences were found at different stages. The predictability of crowding resolution was very high, ranging from 87% in the upper arch and 81% in the lower one. Among the different strategies to gain space, variations in sagittal incisor position were predictable, with a value of 70% both in the upper and lower arch. Conversely, changes in arch diameters were less reliable varying between 49 and 67% in the lower arch and 59–83% in the upper one. Moreover, IPR was the least accurate procedure, wavering at 49% in the upper arch and 42% in the lower arch.
Conclusion: The predictability of crowding resolution during treatment with aligners was high. However, the virtual arch forms obtained at the end of digital planning (vT1) did not correspond with the arch forms at the end of the aligner sequences (T1). The IPR was the least predictable strategy to gain space, being, perhaps, an operator-dependent procedure.