ABSTRACT
OBJECTIVES: Patients in active fixed orthodontic treatment or fixed retention phase may require magnetic resonance (MR) scans of the head and neck region. Orthodontists are challenged to decide whether to keep or remove orthodontic appliances prior to the scans. The aim of this study was to determine the effect of orthodontic appliances on the diagnostic capability of MR images. METHODS: Four electronic databases were searched, with no language restrictions, from database inception to October 2016: PubMed, EMBASE, CINAHL, EBMR. A search in Google Scholar and ProQuest, as well as a manual search, were also conducted. Two independent reviewers assessed articles for inclusion. Original studies including any orthodontic appliance on human subjects were considered. Outcomes measured were development of artefacts, diagnostic quality, accuracy, and treatment outcomes. Risk of bias was assessed with the Cochrane Risk of Bias Assessment and QUADAS-2 tools. RESULTS: Five of 1052 studies identified were included in the final qualitative synthesis. A total of 90 adult human subjects were included. Orthodontic appliances evaluated were brackets, bands, archwires, and fixed retainers. The outcomes assessed were production of artefacts, diagnostic quality and diagnostic accuracy. Detrimental effects on diagnostic quality, and subsequently diagnostic accuracy, rose with increased stainless steel (SS) and proximity to anatomic area of interest. Orthodontic appliances may render images uninterpretable and non-diagnostic. CONCLUSIONS: There is fair evidence to suggest orthodontic appliances, mainly those with SS, cause MR artefacts. Removal of metal orthodontic appliances prior to MR scans is recommended, especially if the area of interest is near the orthodontic appliance. Additional evidence is needed to provide guidelines to clinicians.
