Objective To assess whether there is a short negative psychological influence on adolescent patients at the beginning of the fixed orthodontic treatment. Methods 150 patients（average 14.8 years old） were selected. All the patients accepted the fixed appliance treatment. They completed a questionnaire regarding anxiety and depression at the first day when they came to the hospital（T1） and 7 days after fixed appliance insertion（T2）. 129 effective questionnaires were received. The scales of anxiety and depression of subjects were assessed according to the questionnaires. Results Comparing the scales of questionnaires before treatment（T1） and 7 days after placement of fixed appliance（T2）, there was a significant increase in anxiety and depression scales in female patients, extraction cases and patients who were unwilling to see an orthodontist. Conclusion There is a certain extent of negative psychological influence on adolescent patients during fixed orthodontic treatment. At the first week after the placement of fixed appliance, three kinds of subjects, female patients, extraction cases and patients who were unwilling to see an orthodontist would suffer from anxiety and depression in emotional reflection.
