Candida is an opportunistic pathogen present in about 50-60% of the healthy human population, and becomes pathogenic when the host immune defence is undermined such as in HIV infection. Adhesion and colonization of the oral cavity by Candida albicans is an initial step in candidosis, and the presence of orthodontic and other oral appliances seems to alter the oral ecological environment, hence may tip the balance to favour the candidal presence. The purpose of this paper was to review the literature with specific attention to prevalence; intra-oral density of the candidal organisms; and Candida carriage status in orthodontic patients before, during, and after treatment. The limited amount of literature demonstrated that the density of Candida increases; the most common Candida species isolated in the orthodontic patients was C. albicans; and that there seems to be a direct relationship between the presence of a removable appliance, Candida, and low salivary pH levels. No healthy patients developed Candida infection from the orthodontic appliances. However, there seems to be a trend that some non-Candida carriers converted to Candida carriers following the insertion of the appliances by unknown mechanism. This may indicate a more cautious approach when providing orthodontic treatments to immunocompromised children concerning the possible increased risk of candidal infection.