Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
. 2024 Jun 15;24(1):694.
doi: 10.1186/s12903-024-04435-y.

Predictability of expansion movements performed by clear aligners in mixed dentition in both arches: a retrospective study on digital casts

Saveria Loberto  1 , Chiara Pavoni  2 , Silvia Fanelli  3 , Letizia Lugli  4 , Paola Cozza  5 , Roberta Lione  2
Affiliations
Comparative Study

Predictability of expansion movements performed by clear aligners in mixed dentition in both arches: a retrospective study on digital casts

Saveria Loberto et al. BMC Oral Health. .

Abstract

Background: to evaluate the predictability of expansion achieved in patients in early mixed dentition treated with Clear Aligners (CA), analyzing the efficiency of the expansion at the end of the first set of aligners and at the end of the therapy in the upper and lower arch.

Methods: 36 patients (20 F, 16 M; mean age 8.3 ± 1.5 years) were selected retrospectively from the Department of Orthodontics of the Hospital of Rome "Tor Vergata". All subjects were treated with CA with no other auxiliaries than attachments. For each patient a standardized sequential expansion protocol was planned for both arches. Digital dental casts were created at three observation periods from an intraoral scanner: prior to treatment (T0), at the end of the first set of aligners (T1), at the end of treatment (T2). The 3D models in planned position determined by the first Clincheck (CC) were obtained for comparison with T1 and T2. Six linear transversal measurements were used to evaluate the dimensional changes and the predictability of expansion movements, comparing T1-CC and T2-CC.

Results: a statistically significant increase within the pre-treatment and the final outcomes for all the variables examined was found. In the upper arch, the greatest level of predictability was detected at the level of the first (46.44%) and second deciduous molar width (44.95%) at T1. The analysis of T2-CC changes showed a significant increase in the percentage of predictability of expansion at the level of the first permanent molars, at mesial (54.86%) and distal (58.92%) width. In the lower arch, a higher percentage of predictability than the upper arch was reported at T1-CC and T2-CC, with the greatest values at the level of second (T1-CC: 48.70%; T2-CC: 75.32%) and first deciduous molar width (T1-CC: 45.71%; T2-CC: 72.75%).

Conclusions: CA can induce significant transversal increments. The predictability of expansion is variable, but it did not exceed the 50% during the first set of aligners. It was necessary to apply refinement set to achieve a good predictability for expansion of about 70%. The expansion in the lower arch was observed to be more predictable than in the upper arch.

Keywords: Clear aligner; Digital dental casts; Interceptive treatment; Mandibular expansion; Maxillary expansion; Mixed dentition; Predictability; Transversal changes.

PubMed Disclaimer

Conflict of interest statement

The authors report a funding relationship between themselves and Align Technology. However, Align Technology had no role in the design of the study, in the collection, analyses or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.

Figures

Fig. 1
Fig. 1
Upper and lower arch widths measured on digital models at the level of deciduous canines’ cusp tips (A), vestibular cusp tips of first deciduous molars (B), vestibular sulcus of second deciduous molars (C), mesiobuccal cusp tips of first permanent molars (D), distobuccal cusp tips of first permanent molars (E), and sulci of the first permanent molars (F)
Fig. 2
Fig. 2
Occlusal views of upper arch at pre-treatment (a) and post-treatment (b)
Fig. 3
Fig. 3
Occlusal views of lower arch at pre-treatment (a) and post-treatment (b)
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Artese F. A broader look at Interceptive Orthodontics: what can we offer? Dent Press J Orthod. 2019;24(5):7–8. doi: 10.1590/2177-6709.24.5.007-008.edt. - DOI - PMC - PubMed
    1. Schneider-Moser UEM, Moser L. Very early orthodontic treatment: when, why and how? Dental Press. J Orthod. 2022;27(2):e22spe2. - PMC - PubMed
    1. Pavoni C, Gazzani F, Franchi L, Loberto S, Lione R, Cozza P. Soft tissue facial profile in Class III malocclusion: long-term post-pubertal effects produced by the Face Mask Protocol. Eur J Orthod. 2019;41(5):531–6. doi: 10.1093/ejo/cjz003. - DOI - PubMed
    1. Gazzani F, Pavoni C, Cozza P, Lione R. Stress on facial skin of class III subjects during maxillary protraction: a finite element analysis. BMC Oral Health. 2019;19:31. doi: 10.1186/s12903-019-0724-6. - DOI - PMC - PubMed
    1. Paoloni V, Lugli L, Danesi C, Cozza P. Mandibular morphometric analysis in open bite early treatment relapse subjects: a retrospective observational pilot study. BMC Oral Health. 2022;22(1):555. doi: 10.1186/s12903-022-02546-y. - DOI - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources