Objective. To evaluate the impact of objectively defined orthodontic needs (normative criteria) on the external aspect and mastigation's satisfaction, and to compare these needs to self-perceived ones (subjective criteria) among adolescents. Methods. A cross-sectional study was carried out among all 315 students aged 14-18 years who attended a highschool in Florianópolis, Brazil. A single dentist collected clinical data about malocclusion (Dental Aesthetic Index) and a questionnaire was applied to assess perceived aesthetic and masticatory satisfaction and need for orthodontic treatment. Data analysis included frequency distribution calculation and multiple logistic regression modeling. Results. There were high participation of 95% (n=300) and intra-examiner agreement (Kappa 0.6-1.0). The prevalence of one form of malocclusion was 71.3%. Crowding in one or two incisal segments [OR=2.8 (1.6-4.9)] and overjet [OR=2,4 (1.4-4.3)] were risk factors associated with perceived aesthetic dissatisfaction. Adolescents who had anterior mandibular irregularity [OR=3.3 (1.6-6.9)], overjet [OR=1.7 (1.1-3.0)] and anterior diastema [OR=3.1 (1.4-6.9)] revealed the highest self-perceived need for orthodontic treatment. Conclusions. There are different degrees of objectively defined occlusal problems acceptable in the population which interfere with their decision to seek treatment and have a direct impact on the need of care. Subjective measures should be incorporated to clinical criteria currently used.