The incidence of anterior crossbite, usually as the result of palatally placed maxillary incisors is reported to be around 4-5%
The aim of this study was to compare and evaluate the stability of outcome in patients who had undergone fixed or removable appliance therapy at the mixed dentition stage to correct crossbites affecting one or more incisors.
Patients in early to late mixed dentition with anterior crossbite affecting one or more incisors; anterior crossbite with functional shift; no inherent skeletal Class III discrepancy and no previous orthodontic treatment were eligible. They were randomised to either fixed or removable appliance treatment. Outcome measures were success rates for crossbite correction, overjet, overbite, and arch length. Measurements were made before treatment (T0), end of the retention period (T1) and 2 years after retention (T2).
- 62 children were randomised, 31 to each treatment.
- There were 3-drop outs in the removable group and 2 in the fixed.
- Treatment of crossbite was successful in all except 1 patient in the removable group.
- Treatment duration was significantly shorter in the fixed appliance group (mean, 5.5 months; SD, 1.41) than the removable group (mean, 6.9 months; SD, 2.8)
- The fixed appliance group also showed a significant increase in gingival arch length and overjet.
- At the 2-year follow-up, relapses had occurred in three subjects
- During the follow-up period (T1–T2), a small but significant increase in overbite occurred in the removable appliance group
The authors concluded
In the mixed dentition, anterior crossbite affecting one or more incisors can be successfully corrected by either fixed or removable appliances with similar stability and equally favorable prognoses.
As the authors highlight despite the randomisation there was a significant difference in age between the two groups at baseline with a mean 9.1yrs in removable compared with 10.4yrs in the fixed although there was no difference in other parameters. A previous systematic review by Borrie & Bearn (Dental Elf- 1-Sept-2011) was unable to identify any high quality studies on treating anterior crossbites so this study is welcome.
Wiedel AP, Bondemark L. Stability of anterior crossbite correction: A randomized controlled trial with a 2-year follow-up. Angle Orthod. 2014 Jul 8. [Epub ahead of print] PubMed PMID: 25004240.
Wiedel AP, Bondemark L. Fixed versus removable orthodontic appliances to correct anterior crossbite in the mixed dentition-a randomized controlled trial. Eur J Orthod. 2014 Aug 11. pii: cju005. [Epub ahead of print] PubMed PMID: 25114123.