So far, very little research has been done on the effectiveness of Clear Aligner Therapy. The current study aimed to compare the quality of life regarding the anxiety level, patient satisfaction, and oral health caused by treatment in patients treated with Clear Aligner Therapy and Fixed Orthodontic Treatment. In this descriptive-analytical research, a total of 200 patients were studied, of which 100 patients were undergoing Fixed Orthodontic Treatment and 100 patients were undergoing Clear Aligner Therapy. The Oral Health Impact Profile (OHIP-14) questionnaire was utilized to compare the impact of these two treatments on the life quality of these patients' oral health. Also, the Patient Satisfaction Questionnaire (PSQ-18) was utilized to study patients' satisfaction. In addition, the State-Trait Anxiety Inventory was utilized to check patients' anxiety. In this research, 78 patients were male and 122 were female. The average life quality of health mouth was 53.26, average patient satisfaction was 42.46, and the mean of anxiety caused by treatment was about 72.26. Based on the results, the average anxiety related to the Clear Aligner Therapy group was significantly higher than the Fixed Group Orthodontic Treatment (P<0.001). The average life quality regarding oral health in the Clear Aligner Therapy group was significantly lower than the Fixed Orthodontic Treatment group (P<0.001). The results of the current study revealed that the anxiety level and satisfaction of Clear Aligner Therapy recipients was higher and they had a lower quality of life.
