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. 2017 Dec;18(1):9.
doi: 10.1186/s40510-017-0163-3. Epub 2017 Apr 3.

Prediction of Class II improvement after rapid maxillary expansion in early mixed dentition

Alberto Caprioglio  1 , Chiara Bergamini  2 , Lorenzo Franchi  3 , Nicolò Vercellini  4 , Piero Antonio Zecca  4 , Riccardo Nucera  5 , Rosamaria Fastuca  6   7
Affiliations

Prediction of Class II improvement after rapid maxillary expansion in early mixed dentition

Alberto Caprioglio et al. Prog Orthod. 2017 Dec.

Abstract

Background: The aim of this study is to identify cephalometric pretreatment parameters for prediction of Class II improvement induced by rapid maxillary expansion.

Methods: Lateral cephalograms of 30 patients (mean age 8.3 ± 1.6 years old) showing Class II molar relationship and undergone to rapid maxillary expansion on the upper deciduous molars were traced before treatment, and molar relation changes were evaluated on dental casts before and after treatment. Overall treatment time lasted 10.2 ± 2 months. Good responders (18 subjects, 10 females and 8 males) showed improvement of at least 2.50 mm, and bad responders (12 subjects, 7 females and 5 males) showed no improvement, improvement less than 2.50 mm, or worsening of molar relationship after treatment. Student's t test was used to assess significance of differences between groups, and discriminant analysis allowed identification of predictive pretreatment variables.

Results: Articular angle, superior gonial angle, and mandibular dimensions (Co-Gn, S-Ar, Ar-Go, Go-Me) showed significant differences in the comparison between groups. Mandibular length Co-Gn and superior gonial angle were selected as significant predictive variable for discrimination.

Conclusions: Patients with smaller mandibular length and more acute superior gonial angle are expected to have more chances to improve molar Class II after rapid maxillary expansion.

Keywords: Class II malocclusion; Maxillary expansion; Mixed dentition.

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Figures

Fig. 1
Fig. 1
Haas-type expander on deciduous second molars
Fig. 2
Fig. 2
Cephalometric analysis. Description of the measurements in Table 1
Fig. 3
Fig. 3
Examples of Class II molar relationship at T1 and T2 for good and bad responder. a Patient GR (good responder) at T1. b Patient GR at T2. c Patient BR (bad responder) at T1. d Patient BR at T2
Fig. 4
Fig. 4
Predictive measurements of successful improvement of Class II after RME treatment. 1 mandibular length (Co-Gn), 2 superior gonial angle (Ar^Go^N)
See this image and copyright information in PMC

References

    1. Fontana M, Cozzani M, Caprioglio A. Non-compliance maxillary molar distalizing appliances: an overview of the last decade. Prog Orthod. 2012;13(2):173–184. doi: 10.1016/j.pio.2011.10.002. - DOI - PubMed
    1. Will LA. Transverse maxillary deformities: diagnosis and treatment. Oral Maxillofac Surg. 1996;5:1–28.
    1. Baccetti T, Franchi L, McNamara JA, Jr, Tollaro I. Early dentofacial features of Class II malocclusion: a longitudinal study from the deciduous through the mixed dentition. Am J Orthod Dentofacial Orthop. 1997;11:502–509. doi: 10.1016/S0889-5406(97)70287-7. - DOI - 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 Dentofacial Orthop. 1996;110:417–422. doi: 10.1016/S0889-5406(96)70045-8. - DOI - PubMed
    1. Franchi L, Baccetti T. Transverse maxillary deficiency in Class II and Class III malocclusions: a cephalometric and morphometric study on postero-anterior films. Orthod Craniofac Res. 2005;8(1):21–28. doi: 10.1111/j.1601-6343.2004.00312.x. - DOI - PubMed