Oral Candida in Orthodontic Patients Wearing Removable Orthodontic Appliances: A Systematic Review and Meta-Analysis

Objectives: To evaluate the impact of removable orthodontic appliances (ROA) on oral Candida colonization using a systematic review approach. Methods: We searched for human studies published from inception to April 29, 2024, in PubMed, Scopus, Cochrane central, and the VHL regional portal. Studies on oral Candida colonization in ROA wearers with acrylic components covering the oral mucosa, involving participants aged between 6 and 40 years, were considered eligible. Data on oral Candida colonization categorized by treatment period-before, during, and after ROA use- were the outcomes of interest. Additionally, the data for the treatment period were further subdivided into 4 time-frames: immediate-term (<3 months), short-term (>= 3-6 months), mid-term (>= 6-12 months), and long-term (>= 12 months). The quality of the included studies was assessed using appropriate tools based on their study designs, and a random-effects meta-analysis was conducted to pool the data, reporting odds ratios with 95% confidence intervals. Results: Of the 1,269 records identified, 7 observational studies met the inclusion criteria. These included 3 cross-sectional studies and 4 before-after studies. Based on the follow-up period, no significantly higher prevalence of oral Candida colonization was observed in the immediate-term treatment group compared with the before-treatment group (P = .15). However, oral Candida colonization was significantly more prevalent in the short-term and mid-term ROA wearers compared with the before-treatment group (P = .0006 and P = .001, respectively). Conclusions: Wearing removable orthodontic appliances for longer than 3 months increases the prevalence of oral Candida colonization. However, further randomized controlled trials are needed. (c) 2025 Published by Elsevier Inc. on behalf of FDI World Dental Federation. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)