Objective: To assess the prevalence, intensity, and extent of the impacts on daily performances related to wearing different types of orthodontic appliances. Materials and Methods: A total of 1657 students, 15 to 16 years old, were randomly selected from those attending all secondary schools in Bauru, Sã o Paulo, Brazil. Only those wearing orthodontic appliances at the time of the survey were included. Face-to-face structured interviews were done to collect information about impacts on quality of life related to wearing orthodontic appliances, using the Oral Impact on Daily Performances (OIDP). Adolescents were also clinically examined to assess the type of orthodontic appliance they were wearing. Comparisons, by type of orthodontic appliance and covariables, were performed using nonparametric statistical tests. Results: Three hundred fifty-seven adolescents (36.1% boys and 63.9% girls) undergoing orthodontic treatment participated in the study. The prevalence of condition-specific impacts related to wearing orthodontic appliances was 22.7%. Among adolescents with impacts related to wearing orthodontic appliances, 35.8% reported impacts of severe or very severe intensity and 90.1% reported impacts on only one daily performance, commonly eating or speaking. The prevalence, but not the intensity or the extent, of condition-specific impacts differed by type of orthodontic appliance (P ϭ .001). Conclusions: One in four Brazilian adolescents undergoing orthodontic treatment reported side effects, specific impacts on daily living, related to wearing orthodontic appliances. Such impacts were higher among adolescents wearing fixed rather than removable or a combination of fixed and removable orthodontic appliances. This information could help to inform patients about the frequency and intensity of sociodental impacts during the course of their treatment.