Posterior crossbite occurs when the top teeth or jaw are narrower than the bottom teeth. It can happen on one side or both sides of the dental arches. This condition may increase the likelihood of dental problems (e.g. tooth wear), abnormal development of the jaws, joint problems, and unbalanced facial appearance. Posterior crossbites affect around 4% and 17% of children and adolescents in Europe and America.
Different treatment approaches have been proposed, resulting in many different braces being produced. The basic treatment to correct crossbite correction treatment involves using an orthodontic device on the palate (roof of the mouth) to expand the upper jaw by exerting pressure on both sides of the jaw. The devices can be fixed (e.g. quad‐helix, Haas, Hyrax expander) or removable (e.g. expansion plate). Fixed appliances are bonded to the teeth, while removable devices can be taken out of the mouth by patients.
What was the research?
A systematic review to examine the effects of different braces for posterior crossbite correction.
Who conducted the research?
The research was conducted by a team led by Alessandro Ugolini of the University of Genoa, Genoa, Italy on behalf of Cochrane Oral Health. Paola Agostino, Armando Silvestrini-Biavati, Jayne E. Harrison and Klaus B.S.L. Batista were also on the team.
What evidence was included in the review?
We included 31 randomised controlled trials, including 1,410 children and adolescents. Thirteen studies included children (7 to 11 years old), 12 included adolescents (12 to 16 years old), and six included both. Eight studies were conducted in Turkey, four in Brazil, four in Sweden, three in the USA, three in Italy, two in Canada, and one each in Germany, UK, Switzerland, Iran, Spain, India, and Australia. Twenty‐seven studies were carried out in universities and clinical centres, one study in private practice, and three did not state the location.
What did the evidence say?
For children, expansion of the upper arch with fixed or removable braces can correct posterior crossbites.
When testing fixed and removable braces against each other, the studies found that quad‐helix (fixed appliance) was more successful than expansion plate (removable appliance) and that treatment with quad‐helix took less time.
For other comparisons between different types of treatments, there was no evidence to show that one worked better than another, but we had moderate to low certainty in the results, so future research may change them.
How good was the evidence?
Our confidence in the results is high to moderate for the main results. For the other comparisons, our confidence in the results is low.
What are the implications for dentists and the general public?
Orthodontic treatment with quad‐helix (fixed) or expansion plates (removable) is effective for correcting posterior crossbite in children. Quad‐helix is probably even more effective than expansion plates. For adolescents, there is probably no difference between Hyrax and Haas for posterior crossbite correction.
What should researchers look at in the future?
More randomised controlled trials are required to address the question of what is the best treatment for posterior crossbites in children, adolescents, and adults. Such studies must be well‐designed, well‐conducted, and adequately delivered with subsequent reporting, including high‐quality descriptions of all aspects of the methodology.
Link
Ugolini A, Agostino P, Silvestrini-Biavati A, Harrison JE, Batista KBSL. Orthodontic treatment for posterior crossbites. Cochrane Database of Systematic Reviews 2021, Issue 12. Art. No.: CD000979. DOI: 10.1002/14651858.CD000979.pub3.
This post is an extended version of the review’s plain language summary, compiled by Anne Littlewood at the Cochrane Oral Health Editorial Base.
Cochrane Oral Health 