American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection in the orthodontic literature—use and trends: A systematic review

Introduction The American Association of Orthodontists Foundation (AAOF) Craniofacial Growth Legacy Collection is a digital repository of records from 9 craniofacial growth study collections in the United States and Canada. The purposes of this article were to describe the use of materials from the AAOF Craniofacial Growth Legacy Collection in the orthodontic literature in comparative and follow-up studies, and to analyze trends before and after the project's launch in 2009. Methods An electronic search without date or language restriction was conducted in the following databases: PubMed, Embase, Evidence-Based Medicine Reviews, and CINAHL. Grey literature resources and the bibliographies of the selected studies were also consulted. Three independent reviewers assessed the studies for inclusion. The criteria were human subjects of any age, sex, and ethnicity; at least 1 of the 9 AAOF legacy collections used as either the main sample population or the comparison or control; and orthodontic outcomes assessed. Data were analyzed using STATA software (version 14.2; StataCorp, College Station, Tex). Results A total of 199 studies (127 follow-up, 72 comparative) were included. The most commonly used collection in comparative studies was the Michigan Growth sample. The number of published studies more than doubled after the AAOF Legacy Collection project testing and launch in 2009. The increase continued through 2010 to 2014, during which there was a trend to use multiple collections. The Burlington Growth collection was the most commonly used collection for follow-up studies. The overall use of the legacy collection showed a small increase in published studies after 2009. Conclusions The overall numbers of published studies in the comparative and follow-up categories increased after 2009, reflecting the efforts of the AAOF team and collection curators to make the records available worldwide. Further research should consider studying each collection to identify utilization predictors.