RESUMO
OBJECTIVE: The aim of this study was to evaluate the frequency of Staphylococcus aureus, Pseudomonas aeruginosa, and Candida species in removable orthodontic appliances (ROA) and the support oral mucosa in children. STUDY DESIGN: The study participants comprised 55 patients aged 6-12 years requiring ROA. The samples of biofilm colonization from the support oral mucosa and the ROA were taken prior to the use of the ROA (T0) and 4 weeks (T1) after ROA placement. The biofilm samples were seeded on chromogenic culture plates and incubated for 24-48 h. RESULTS: The microbial species evaluated were not present in either the support oral mucosa nor in the ROA at T0. After 4 weeks, P. aeruginosa was found in the support oral mucosa with a frequency of 60%, Candida spp. with 30.9% and S. aureus with 89.09%; in the ROA, P. aeruginosa with 67.7%, Candida spp. with 32.7%, while S. aureus with 90.9%. In the ROA were found C. glabrata in 15 cases, C. albicans in 14 cases, C. tropicalis in two cases, and C. krusei in one case. In the oral mucosa there were 10 cases of C. glabrata, 14 cases of C. albicans, one case of C. tropicalis, and 0 cases of C. krusei. CONCLUSIONS: The frequency of S. aureus, P. aeruginosa, and Candida spp. increased after the orthodontic treatment in either the ROA and or in the support oral mucosa. There is a direct relation between the use of the ROA and the increase of periodontal-pathogenic microorganisms.