Treatment effect of bone-anchored maxillary protraction in growing patients compared to controls: a systematic review with meta-analysis

OBJECTIVE: The aim of this systematic review was to determine which evidence level supports maxillary advancement after bone-anchored maxillary protraction (BAMP) in growing patients compared to controls. SEARCH METHODS: PubMed, Cochrane, Embase, Scopus, and Web-of-Science databases were searched with no restrictions on publication status or year. SELECTION CRITERIA: Prospective and retrospective human studies about BAMP, in at least three patients, were included. Authors were contacted when necessary, and reference lists of the included studies were screened. DATA COLLECTION AND ANALYSIS: Two authors undertook independent data extraction with conflict resolution by a third author. Risks of bias were assessed. A meta-analysis for estimates of changes for ANB angle, Wits appraisal, and incisor to mandibular plane angle (IMPA) angle of BAMP treatment compared to control groups was performed. RESULTS: A total of 449 articles were initially retrieved; 28 full-text articles met the inclusion criteria. Sample sizes ranged from 3 to 52 patients. There was heterogeneity in cephalometric outcomes reported, which prevented the comparison of certain outcomes. ANB angle improved more with BAMP in the maxilla combined with facemask (bone-anchored facemask, BAFM) compared to traditional facemask therapy: this was statistically but not clinically significant (0.2 degrees). No data are available for BAMP with skeletal anchorage in both jaws in combination with Class III elastics (bone-anchored Class III elastics, BAC3E). Likewise, no statistically significant differences in Wits appraisal were found (less than 1 mm). Lower incisor retroclination and facial height seemed to be better controlled with BAC3E compared to BAFM. CONCLUSIONS: The level of evidence available to support the maxillary advancement effect after BAMP was low. Publications reporting results based on identical samples tended to suggest overly positive results of BAMP. The differences in sagittal correction between BAMP and traditional facemask therapy were small and of questionable clinical significance. Long-term follow-up results are not available and, therefore, much needed. LIMITATIONS: Most articles had a low level of evidence and some included a historical control group. REGISTRATION: PROSPERO database number CRD42015023366.