Transverse discrepancies in the maxilla can be treated by rapid maxillary expansion (RME). This is ideally carried out during the pubertal growth spurt, usually before 15 years of age. In older patients surgically assisted rapid maxillary expansion (SARME) has been used.  The aim of this review was to assess the long-term dental and skeletal changes associated with SARME.

A number of electronic databases were searched (SCIRUS, OVID, ISI Web of Knowledge, Cochrane Library, VHL (Virtual Health Library), and PubMed) with no language restrictions.  Papers meeting the following criteria were included; prospective and retrospective human clinical trials; patients undergoing SARME; measurements in dental casts or postero-anterior (PA) cephalometric radiographs; (4) Tooth (TB) or bone borne (BB) palatal distractor appliance; follow-up of at least 1 year after expansion; no other craniofacial surgery.  Selection and grading of the quality of the papers was carried out independently.

Ten studies were included; seven articles were ranked as moderate and 3 as low methodological quality. Those of low quality were excluded leaving & non-randomised clinical trials  (5 prospective and 2 retrospective).  Meta-analysis was conducted using data from the 5 prospective studies.

• The meta-analysis showed a significant long-term increase in the maxillary alveolar width, and in the inter-canine and inter-molar width in patients submitted to SARME.
• Alveolar width showed no relapse from just after the expansion until the last follow-up assessment. Although the inter-canine width showed a significant relapse of 1.5 mm, its increase from the initial phase to the follow-up evaluation was highly significant.
• It may be inferred from these results that the alveolar width changes remain stable and that some relapse is expected in the inter-canine width, thus some over correction may be advisable.

The authors concluded

There is moderate evidence to conclude that maxillary alveolar width and inter-canine and inter-molar width have a long-term significant increase as a result of surgically assisted rapid maxillary expansion. A significant relapse is expected in the inter-canine width after expansion.

Comment

While the searches conducted for this review used a number of databases only a small number of studies were identified. This is similar to other reviews in the area.  The fact that several of the included studies had no control groups, no reporting of dropouts and only 3 out of the 10 studies originally selected had the outcomes assessed blindly all impact on the quality of the evidence available to assess this intervention.  The authors also raise the issues of the different ways in which the measurements of the skeletal changes were made which adds another potential bias.  While there have been a number of reviews of different outcomes from RME there is still a lack of high quality randomised trial to guide clinical practice in this area.

Links

Vilani GN, Mattos CT, Ruellas AC, Maia LC. Long-term dental and skeletal changes in patients submitted to surgically assisted rapid maxillary expansion: A meta-analysis. Oral Surg Oral Med Oral Pathol Oral Radiol. 2012 Aug 1. [Epub ahead of print] PubMed PMID: 22858019.

Zuccati G, Casci S, Doldo T, Clauser C. Expansion of maxillary arches with crossbite: a systematic review of RCTs in the last 12 years. Eur J Orthod. 2011 Dec 9. [Epub ahead of print] PubMed PMID: 22158610.

Baratieri C, Alves M Jr, de Souza MM, de Souza Araújo MT, Maia LC. Does rapid  maxillary expansion have long-term effects on airway dimensions and breathing? Am J Orthod Dentofacial Orthop. 2011 Aug;140(2):146-56. Review. PubMed PMID: 21803251.

Gordon JM, Rosenblatt M, Witmans M, Carey JP, Heo G, Major PW, Flores-Mir C. Rapid palatal expansion effects on nasal airway dimensions as measured by acoustic rhinometry. A systematic review. Angle Orthod. 2009 Sep;79(5):1000-7. Review. PubMed PMID: 19705938.

Verstraaten J, Kuijpers-Jagtman AM, Mommaerts MY, Bergé SJ, Nada RM, Schols JG; Eurocran Distraction Osteogenesis Group. A systematic review of the effects of bone-borne surgical assisted rapid maxillary expansion. J Craniomaxillofac Surg. 2010 Apr;38(3):166-74. Epub 2009 Aug 6. Review. PubMed PMID: 19664932.

Lagravere MO, Major PW, Flores-Mir C. Long-term skeletal changes with rapid maxillary expansion: a systematic review. Angle Orthod. 2005 Nov;75(6):1046-52. Review. PubMed PMID: 16448254.

Lagravere MO, Major PW, Flores-Mir C. Long-term dental arch changes after rapid maxillary expansion treatment: a systematic review. Angle Orthod. 2005 Mar;75(2):155-61. Review. PubMed PMID: 15825776.

Harrison JE, Ashby D. Orthodontic treatment for posterior crossbites. Cochrane Database Syst Rev. 2001;(1):CD000979. Review. PubMed PMID: 11279699.