Alar width changes due to surgically-assisted rapid palatal expansion: A meta-analysis

A major objective of orthognatic surgery is the aesthetic outcome. Treatments only correcting for dentoskeletal deformities are not sufficient for optimal facial results because undesirable soft tissue changes may accompany skeletal manipulations. The primary objective of this study was to investigate alar base width (ABW) changes a minimum of 6 months following surgically-assisted rapid palatal expansion (SARPE). The following electronic databases and citation indices were searched: PubMed, Cochrane Library, Scopus, Web of Science, Embase, and Virtual Health Library. The search included articles published until September 2015 without language restriction. The intervention was SARPE with maxillary vestibular incision from first molar to contralateral first molar, a modified LeFort I osteotomy with or without pterygomaxillary disjunction, and a V-Y closure. The primary outcome was the unstandardized mean difference between pre and postoperative ABW. A random effects meta-analysis was performed to combine study results, and included studies that were assessed for statistical heterogeneity using a Chi-square test for independence. The results of this meta-analysis (N = 41) showed a significant + 1.74 mm, 95% CI [0.14, 3.34] ABW increase in patients submitted to SARPE. There was no statistical heterogeneity among included studies (χ(2) = 0.03; df = 2; P = 0.98). ABW increases were observed despite including cinched patients in the analysis. None of the three included studies were completely free of bias. The most prominent flaws were measurement bias, limited sample size, and patient recruitment.