Agostino, P., Ugolini, A., Signori, A., Silvestrini-Biavati, A., Harrison, J. E., and Riley, P. (2014). Orthodontic treatment for posterior crossbites. Cochrane Database of Systematic Reviews, Issue 8, Art. No.: CD000979. DOI: 10.1002/14651858.CD000979.pub2 https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000979.pub2/full

The authors concluded that there is some evidence which suggests the quadhelix appliance may be more successful than removable expansion plates at correcting posterior crossbites and expanding the intermolar width for children in the early missed dentition (aged 8–10 years).

 

Birnie, D. J. and McNamara, T. G. (1980). The quadhelix appliance. British Journal of Orthodontics, 7, 115–20. [DOI: 10.1179/bjo.7.3.115] [PubMed: 7002208].

The fabrication, management, and modifications of the quadhelix appliance are described in this paper.

 

Bucci, R., D’Antò, V., Rongo, R., Valletta, R., Martina, R., and Michelotti, A. (2016). Dental and skeletal effects of palatal expansion techniques: a systematic review of the current evidence from systematic reviews and meta-analyses. Journal of Oral Rehabilitation, 43, 543–64. [DOI: 10.1111/joor.12393] [PubMed: 27004835]

An interesting systematic review which looked at all the previous systematic reviews on this topic. They concluded that palatal expansion is effective in the correction of posterior crossbites in the short term. There is more evidence to support the use of RME rather than slow maxillary expansion. The amount of skeletal expansion is less than dento-alveolar expansion. More evidence is required on the long-term effects.

 

Hermanson, H., Kurol, J., and Ronnerman, A. (1985). Treatment of unilateral posterior crossbites with quadhelix and removable plates. A retrospective study. European Journal of Orthodontics, 7, 97–102. [DOI: 10.1093/ejo/7.2.97] [PubMed: 3926519].

In this study it was found that the clinical results achieved were similar with the two types of appliance. However, the number of visits and chairside time were greater for the removable appliance. The authors calculated that the mean cost of treatment was 40% greater for the removable appliance compared with the quadhelix.

 

Herold, J. S. (1989). Maxillary expansion: a retrospective study of three methods of expansion and their long-term sequelae. British Journal of Orthodontics, 16, 195–200. [DOI: 10.1179/bjo.16.3.195] [PubMed: 2669948].

 

Kilic, N., Kiki, A., and Oktay, H. (2008). Condylar asymmetry in unilateral posterior crossbite patients. American Journal of Orthodontics and Dentofacial Orthopedics, 133, 382–7. [DOI: 10.1016/j.ajodo.2006.04.041] [PubMed: 18331937].

 

Lagravère, M. O., Carey, J., Heo, G., Toogood, R. W., and Major, P. W. (2010). Transverse, vertical and anteroposteior changes from bone-anchored maxillary expansion vs traditional rapid maxillary expansion; a randomised clinical trial. American Journal of Orthodontic and Dentofacial Orthopedics, 137, 304.e1–12. [DOI: 10.1016/j.ajodo.2009.09.016] [PubMed: 20197161]

 

Lee, R. (1999). Arch width and form: a review. American Journal of Orthodontics and Dentofacial Orthopedics, 115, 305–13. [DOI: 10.1016/S0889-5406(99)70334-3] [PubMed: 10066980].

 

Linder-Aronson, S. and Lindgren, J. (1979). The skeletal and dental effects of rapid maxillary expansion. British Journal of Orthodontics, 6, 25–9. [DOI: 10.1179/bjo.6.1.25] [PubMed: 396941].

 

Marshall, S. D., English JD Jr, Huang GJ, Messersmith ML, Nah HD, Riolo ML, et al. (2008). Ask us – long term stability of maxillary expansion. American Journal of Orthodontics and Dentofacial Orthopedics, 133, 780–1. [DOI: 10.1016/j.ajodo.2008.02.001] [PubMed: 18538225]

 

McNally, M. R., Spary, D. J., and Rock, W. P. (2005). A randomized controlled trial comparing the quadhelix and the expansion arch for the correction of crossbite. Journal of Orthodontics, 32, 29–35. [DOI: 10.1179/146531205225020769] [PubMed: 15784941]

This study found that both appliances were equally effective, but that the expansion arch could be made at the chair side, did not require additional attachments, and was cheap to fabricate. However, 70% of patients disliked the appearance of the expansion arch.