Skeletal movements and changes in the position of the hyoid bone as a result of orthognathic surgery may have on the oropharyngeal airway.  The aim of this article was to report the results from a meta-analysis of the scientific literature concerned with changes in the airway in human clinical trials in adult subjects submitted to orthognathic surgery to correct sagittal skeletal deformities

The databases LILACS, IBECS, Medline, The Cochrane Library, SCIELO databases, Scirus, Ovid and the System for Information on Grey Literature in Europe (SIGLE) were searched.  In addition the reference lists of all included studies were searched and experts contacted to identify unpublished and ongoing studies.

49 articles met the inclusion criteria, Articles were independently assessed for quality and a meta-analysis was performed. Heterogeneity was assessed amongst the studies and results were presented in forest plots. Only studies with moderate or high methodological soundness were included.

They found:-

Moderate evidence  to support a significant decrease in the oropharyngeal airway in mandibular setback surgery, a milder decrease in bimaxillary surgery to correct Class III and an increase in maxillomandibular advancement surgery.

They concluded:-

Three-dimensional studies are important in the near future to confirm the results observed using two-dimensional tools, as evidence is lacking on the volume changes of the airway after orthognathic surgery.

Mattos CT, Vilani GN, Sant’anna EF, Ruellas AC, Maia LC. Effects of orthognathic surgery on oropharyngeal airway: a meta-analysis. Int J Oral Maxillofac Surg. 2011 Jul 20. [Epub ahead of print] PubMed PMID: 21782388.