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Randomized Controlled Trial
. 2017 Nov 6;18(1):36.
doi: 10.1186/s40510-017-0189-6.

Mandibular response after rapid maxillary expansion in class II growing patients: a pilot randomized controlled trial

Roberta Lione  1   2 , Valerio Brunelli  3   4 , Lorenzo Franchi  5   6 , Chiara Pavoni  3   4 , Bernardo Quiroga Souki  7 , Paola Cozza  3   4
Affiliations
Randomized Controlled Trial

Mandibular response after rapid maxillary expansion in class II growing patients: a pilot randomized controlled trial

Roberta Lione et al. Prog Orthod. .

Erratum in

Abstract

Background: The aim of this pilot randomized controlled trial (RCT) was to evaluate the sagittal mandibular response induced by rapid maxillary expansion (RME) therapy in mixed dentition patients with class II malocclusion, comparing the effects of bonded RME and banded RME with a matched untreated class II control group.

Methods: This RCT was designed in parallel with an allocation ratio of 1:1:1. The sample consisted of 30 children with a mean age of 8.1 ± 0.6 years who were randomly assigned to three groups: group 1 treated with bonded RME, group 2 treated with banded RME, and group 3 the untreated control group. All patients met the following inclusion criteria: early mixed dentition, class II molar relationship, transverse discrepancy ≥ 4 mm, overjet ≥ 5 mm, and prepubertal skeletal maturity stage (CS1-CS2). The expansion screw was activated one quarter of a turn per day (0.25 mm) until overcorrection was reached. For each subject, lateral cephalograms and plaster casts were obtained before treatment (T1) and after 1 year (T2). A randomization list was created for the group assignment, with an allocation ratio of 1:1:1. The observer who performed all the measurements was blinded to group assignment. The study was single-blinded in regard to statistical analysis.

Results: RME was effective in the correction of maxillary deficiency. Class II patients treated with both types of RME showed no significant improvement of the anteroposterior relationship of the maxilla and the mandible at both skeletal and occlusal levels. The acrylic splint RME had significant effects on reducing the skeletal vertical dimension and the gonial angle.

Conclusions: The orthopedic expansion did not affect the sagittal relationship of class II patients treated in the early mixed dentition when compared with the untreated control group. Additional studies with a larger sample are warranted to elucidate individual variations in dento-skeletal mandibular response to the maxillary expansion protocol in class-II-growing patients.

Trial registration: ClinicalTrials.gov NCT03159962 .

Keywords: Class II malocclusion; Growing subjects; Mandibular response; Rapid maxillary expansion.

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Conflict of interest statement

Ethics approval and consent to participate

Signed informed consent for releasing diagnostic records for scientific purposes was available from the parents of the patients. The protocol was reviewed and approved by the Ethics Committee of the University of Rome “Tor Vergata” (Rome, Italy) (protocol number 130/14), and procedures followed adhered to the World Medical Organization Declaration of Helsinki.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1
Fig. 1
a Bonded RME. b Banded RME
Fig. 2
Fig. 2
Cephalometric points, lines, and angles used in analysis: SNA angle (maxillary sagittal position), SNB angle (mandibular sagittal position), ANB angle (maxillomandibular sagittal discrepancy), point Pg to Nasion perpendicular (sagittal mandibular position relative to Frankfurt plane), mandibular total length (Co-Gn), SN to mandibular plane (Me-Go), gonial angle (Ar-Go-Me), lower anterior facial height (ANS-Me), overjet, overbite; molar relationship
Fig. 3
Fig. 3
Study flow chart
See this image and copyright information in PMC

References

    1. Baratieri C, Alves MJ, Bolognese AM, Nojima MCG, Nojima LI. Changes in skeletal and dental relationship in class II division I malocclusion after rapid maxillary expansion: a prospective study. Dental Press J Orthod. 2014;19:75–78. doi: 10.1590/2176-9451.19.3.075-081.oar. - DOI - PMC - PubMed
    1. Caprioglio A, Bergamini C, Franchi L, Vercellini N, Zecca PA, Nucera R, Fastuca R. Prediction of class II improvement after rapid maxillary expansion in early mixed dentition. Prog Orthod. 2017;18:9. doi: 10.1186/s40510-017-0163-3. - DOI - PMC - PubMed
    1. Tollaro I, Baccetti T, Franchi L, Tanasescu CD. Role of posterior transverse interarch discrepancy in class II, division 1 malocclusion during the mixed dentition phase. Am J Orthod Dentofac Orthop. 1996;110:417–422. doi: 10.1016/S0889-5406(96)70045-8. - DOI - PubMed
    1. Gianelly AA. Rapid palatal expansion in the absence of crossbite: add value? Am J Orthod Dentofac Orthop. 2003;124:362–365. doi: 10.1016/S0889-5406(03)00568-7. - DOI - PubMed
    1. McNamara JJ. Maxillary transverse deficiency. Am J Orthod Dentofac Orthop. 2000;117:567–570. doi: 10.1016/S0889-5406(00)70202-2. - DOI - PubMed

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