This is not the most recent version of the article. View current version (8 AUG 2014)
Orthodontic treatment for posterior crossbites
Editorial Group: Cochrane Oral Health Group
Published Online: 22 JAN 2001
Assessed as up-to-date: 15 NOV 2000
Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
How to Cite
Harrison JE, Ashby D. Orthodontic treatment for posterior crossbites. Cochrane Database of Systematic Reviews 2001, Issue 1. Art. No.: CD000979. DOI: 10.1002/14651858.CD000979.
- Publication Status: Edited (no change to conclusions)
- Published Online: 22 JAN 2001
This is not the most recent version of the article. View current version (08 AUG 2014)
'Posterior crossbite' occurs when the top back teeth bite inside the bottom back teeth. When it affects one side of the mouth the lower jaw may have to move to one side to allow the back teeth to meet together. It is unclear what causes posterior crossbites and they may develop or improve at any time from when the baby teeth come into the mouth to when the adult teeth come through. Several treatments have been recommended to correct this problem. Some treatments widen the upper teeth whilst others are directed at treating the cause of the posterior crossbite e.g. breathing problems or sucking habits. Most treatments have been used at each stage of dental development.
The aim of this review was to evaluate orthodontic treatments used to expand the maxillary dentition and correct posterior crossbites.
All randomised and controlled clinical trials identified from the Cochrane Oral Health Group Trials Register, a MEDLINE search using the Mesh term Palatal Expansion Technique and relevant free text words, handsearching the British, European and American journals of orthodontics and Angle Orthodontist, and the bibliographies of papers and review articles which reported the outcome of orthodontic treatment to expand the maxillary dentition and/or correct a posterior crossbite that were published as abstracts or papers between 1970 and 1999.
All randomised and controlled clinical trials published as full papers or abstracts which reported quantitative data on the outcomes crossbite correction, molar and/or canine expansion, signs and symptoms of temporomandibular joint dysfunction or respiratory disease.
Data collection and analysis
Data were extracted without blinding to the authors, treatments used or results obtained.
The first named authors of randomised and controlled clinical trials were written to in an attempt to establish the method of randomisation/allocation and identify unpublished studies.
Odds ratio, relative risk, relative risk reduction, absolute risk reduction, the number needed to treat and corresponding 95% confidence intervals, were calculated for event data. The weighted mean difference and 95% confidence intervals were calculated for continuous data.
Using the search strategy seven randomised and five controlled clinical trials were identified but following correspondence with the authors, three of the randomised and one of the controlled clinical trials were reclassified giving five randomised and seven controlled clinical trials for inclusion in the review. For the update an additional CCT was found giving five RCTs and eight CCTs for inclusion in this update.
Trials comparing occlusal grinding in the primary dentition with/without an upper removable expansion appliance in the mixed dentition versus no treatment, banded versus bonded and two point versus four point rapid maxillary expansion, banded versus bonded slow maxillary expansion, transpalatal arch with/without buccal root torque, an upper removable expansion appliance versus quad-helix were identified.
Occlusal grinding in the primary dentition with/without the addition of an upper removable expansion plate, in the mixed dentition for those children who did not respond to grinding, was shown to be effective in preventing a posterior crossbite in the primary dentition from being perpetuated to the mixed and permanent dentitions.
No evidence of a difference in treatment effect (molar and canine expansion) between the test and control intervention was found in the trials which compared banded versus bonded and two point versus four point rapid maxillary expansion, banded versus bonded slow maxillary expansion, transpalatal arch with/without buccal root torque, or upper removable expansion appliance versus quad-helix. Insufficient data were provided in the paper comparing two point versus four point rapid maxillary expansion to allow a formal analysis.
The evidence from the trials reported by Thilander 1984 and Lindner 1989 suggests that removal of premature contacts of the baby teeth is effective in preventing a posterior crossbite from being perpetuated to the mixed dentition and adult teeth. When grinding alone is not effective, using an upper removable expansion plate to expand the top teeth will decrease the risk of a posterior crossbite from being perpetuated to the permanent dentition.
The comparisons of treatments made in the trials reported by Mossaz-Joëlson 1989; Schneidman 1990; Ingervall 1995; Asanza 1997 and Sandikçioglu 1997 were inconclusive so recommendations for clinical practice can not be made based on the results of these trials. However, these trials were small and inadequately powered so further studies, with appropriate sample sizes, would be required to assess the relative effectiveness of these interventions.
Plain language summary
Orthodontic treatment for posterior crossbites
Early treatment of posterior crossbites appears to prevent them from being passed on to the adult dentition. However, this is only based on data from two small studies.
'Posterior crossbite' occurs when the top back teeth bite inside the bottom back teeth. It is unclear what causes posterior crossbites and they may develop or improve at any time from when the baby teeth come into the mouth to when the adult teeth come through. If they affect one side of the mouth the lower jaw may need to move to one side to allow the back teeth to meet together. This movement may have long term effects on the growth of the teeth and jaws. Several treatments have been used to correct posterior crossbites and stop this abnormal movement.
後牙錯咬(posterior crossbite)發生在上顎後牙咬在下顎後牙的內側。當它只影響到口內單側齒列，下顎可能會往側方移動，來讓後牙可以咬到。對於後牙錯咬的原因，或是它為何發生，或它從乳牙萌出到成人牙萌出，這時期之間何時會改善，都是未明的。有很多治療方式可以改善這個問題。有些是將上顎牙齒撐寬，有些是想辦法治療後牙錯咬的成因，例如呼吸問題或吮吸習慣(sucking habits)。大部分的治療都在牙齒發育的階段。
所有隨機和對照臨床試驗都來自於Oral Health Group Search Strategy 的Cochrane Controlled Trials Register，以及儲存在Cochrane Collaboration Oral Health Group Database of Clinical Trials的文章，在MEDLINE搜尋引擎上，利用關鍵字:上顎撐寬術(Palatal Expansion Technique)和相關的字句來做查詢，並手動查詢British, European and American journals of orthodontics和Angle Orthodontist，和那些文章或文獻回顧的標題包含有撐寬上顎齒列或矯治後牙錯咬的結果，這些摘要或文章都是在1970到1999年之間發表的。
選取的資料沒有隱蔽作者、治療方法或結果。我們會聯絡隨機和對照臨床試驗的第一作者，為了建立隨機分配的方法，和辨認出未發表的研究。比值比、相對危險度、相對危險度減少、絕對危險度減少、需要治療的個數和相對的95%信賴區間，在每個事件數據(event data)都被加以計算。加權平均差和95%信賴區間，在每個連續數據(continuous data)都被加以計算。
利用以上搜尋策略，找出了7個隨機、5個對照臨床試驗，但和文章作者連絡後，3個隨機、1個對照臨床試驗被重新分類，最後本篇文獻回顧包含了5個隨機、7個對照臨床試驗。近期文獻又有額外一篇對照臨床試驗，所以共有5個隨機、8個對照臨床試驗。這些試驗包括以下的比較：在混合齒列時期(mixed dentition)，對乳齒列(primary dentition)做咬合調整，配合有無上顎活動式撐寬裝置的組別，會和沒有治療的組別做比較；套環式(banded)或黏著式(bonded)以及以兩點或四點做支撐的上顎快速撐寬；套環式或黏著式的上顎慢速撐寬，橫顎弓(transpalatal arch)有無頰側牙根扭矩(buccal root torque)；上顎活動式撐寬裝置與四螺圈裝置(quadhelix)的比較。在混合齒列時期(mixed dentition)，對乳齒列(primary dentition)做咬合調整，配合有無上顎活動式撐寬裝置的組別，如果做咬合調整對這些小孩沒有效果，治療最好從乳齒列延續到混合齒列和恆齒列(permanent dentition)，即可有效的預防後牙錯咬的發生。以下的試驗，並無證據顯示經過治療後，實驗組和控制組在臼齒和犬齒撐寬量有所差距，包括:套環式或黏著式以及以兩點或四點做支撐的上顎快速撐寬；套環式或黏著式的上顎慢速撐寬，橫顎弓有無頰側牙根扭矩；上顎活動式撐寬裝置與四螺圈裝置的比較。而在以兩點或四點做支撐的上顎快速撐寬的文章中，數據還不足以建立一個正式的分析。
根據Lindner(1989)和Thilander(1984)年所提出的試驗，移除乳牙的過早接觸點(premature contact)，是能有效預防後牙錯咬延續到混合齒列和恆齒列的。如果只做咬合調整沒有效果，配合上顎活動式撐寬裝置，來撐寬上顎牙齒，可以減少後牙錯咬延續到恆齒列發生的機會。比較Asanza (1997); Sandikcioglu (1997); MossazJoelson (1989); Ingervall (1995); Schneidman (1990)等人的試驗，其結果是沒有定論的，所以無法基於這些試驗的結果給予臨床操作的建議。然而，這些試驗都是小型、沒有適當檢定的，所以有恰當樣本大小的進一步研究是需要的，才能評估這些治療相對的成效。
此翻譯計畫由臺灣國家衛生研究院(National Health Research Institutes, Taiwan)統籌。