Abstract: Objective To investigate the influencing factors of restart in patients receiving clear aligner treatment and provide clinical reference for orthodontics. Methods A total of 354 patients receiving clear aligner treatment were collected and divided into restart group and non-restart group. Twelve factors were analyzed between two groups. SPSS 19.0 was used for statistical analysis, and univariate analysis and multivariate Logistic regression analysis were used to screen out factors related to restart. Results The restart rate of 354 patients with clear aligners was 39.27%, including 31 male patients (8.76%) and 108 female patients (30.51%). Further multivariate analysis showed that the restart risk of adult patients was lower than that of juvenile patients, about 40% of risks faced by juvenile patients (P=0.024). Patients with poor cooperation had a 5.7-fold increased risk of restart (P=0.000). The risk of restart increased about 2.7 times for patients requiring elastic traction cooperation (P=0.006). The restart rate of patient with over 48 treatment steps was 3.6 times higher than that of patients with less than 24 treatment steps (P=0.027). Conclusion Age of the patient (juvenile patient), need for elastic traction, poor cooperation and treatment steps (>48) are the influencing factors which would increase the risk of restart. It is suggested tha monitoring and guidance of these patients should be strengthened in clinic.

Key words: clear aligner treatment, restart, influencing factor